Question: Is mankind's impact the main driver of alterations in the global climate?

Climate Change and Human Influence
I find my opponent's argument perplexing. He has taken the opposing stance, yet his arguments seem to support the affirmative side. Perhaps he is employing sarcasm, but it's unclear. Here's the case for the affirmative:
Point A: Climate Change is Real
Subpoint 1: Scientific Agreement
"Carbon dioxide and other greenhouse gases are accumulating in the atmosphere, trapping the sun's heat and causing the planet to warm. Although local temperatures naturally fluctuate, the average global temperature has increased at an unprecedented rate over the past 50 years. Unless we limit emissions causing climate change, average U.S. temperatures could rise by 3 to 9 degrees by the end of the century." Scientists are unanimous in their belief that climate change is a genuine threat, as evidenced by numerous scholarly studies. 97% of climate scientists concur. (1)(2)(3)(4)(5)(6)(7)
Point B: Humanity Influences Climate Change
Subpoint 1: Scientific Agreement
"The United States Global Change Research Program (including the Department of Defense, NASA, National Science Foundation, and other government agencies) has stated that 'global warming is clear and primarily human-induced' and that 'climate changes are occurring in the United States and are projected to grow.'"(3)"The climate change denial mechanism has been working hard to discredit the latest UN Intergovernmental Panel on Climate Change (IPCC) report, which confirms that climate change is happening and that human activity is mainly responsible."(5)"Ninety-seven percent of climate scientists agree that the climate-warming trends over the past century are very likely due to human activities, and most leading scientific organizations worldwide have issued public statements endorsing this position."(6)Once again, there is overwhelming scientific consensus.
Subpoint 2: Carbon Emissions, a Human Product, are a Major Cause
"The only way to explain the pattern [of climate change] is to include the effect of greenhouse gases (GHGs) emitted by humans."(2)"Most climate scientists agree that the primary cause of the current global warming trend is human expansion of the 'greenhouse effect' - warming that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere prevent heat from escaping. Long-lived gases, remaining semi-permanently in the atmosphere, which do not respond physically or chemically to changes in temperature, are described as 'forcing' climate change"(7)Scientists concur that humanity has altered the balance

"On the rebuttals, apologies. I misworded the debate structure. It should be "no rebuttals by pro." Just present your arguments affirming the resolution. Thanks."As said by Con, I will present my argumentsThe typical argument is like this [1] The Earth's atmosphere keeps the planet much warmer than it would be without an atmosphere. The main gases which contribute to this are carbon dioxide, methane and water vapor. Collectively these are called greenhouse gases. The ability of these gases to act as greenhouse gases can be shown in a laboratory. The quantity of these greenhouse gases in the atmosphere has increased sharply since the Industrial Revolution, and their concentration continues to do so. The concentration of these gases has increased as a consequence of human activity. The temperature of Earth's atmosphere has been increasing and continues to increase. The increase in global temperature correlates with the increases of greenhouse gases. Just about every scientist agrees with these 7 premises. Even some skeptics do too and I believe Con does (although I could be wrong). The following premise is the disputed one8. The increase in temperature has been caused by the increase in greenhouse gases from humans.We know the climate on Earth has changed before. We must understand that in order for a climate to rise naturally, A forcing must exist to force the climate to change. There's no known forcing that fits the fingerprint of the evidence we see, except one, anthropogenic greenhouse gases.We know that humans are producing 30 billion tons of Co2 a year in the atmosphere [3]. Let's see evidence that follows from this.I will paste 6 evidences from “10 Indicators of a Human Fingerprint on Climate Change” [2]1. When we measure the type of carbon accumulating in the atmosphere, we observe more of the type of carbon that comes from fossil fuels [4]2. This is corroborated by measurements of oxygen in the atmosphere. Oxygen levels are falling in line with the amount of carbon dioxide rising, just as you'd expect from fossil fuel burning which takes oxygen out of the air to create carbon dioxide [5]3. So we know humans are raising CO2 levels. What's the effect? Satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat, thus finding "direct experimental evidence for a significant increase in the Earth's greenhouse effect". [6]4. If an increased greenhouse effect is causing global warming, we should see certain patterns in the warming. For example, the planet should warm faster at night than during the day. This is indeed being observed [7]5. With the lower atmosphere (the troposphere) warming and the upper atmosphere (the stratosphere) cooling, another consequence is the boundary between the troposphere and stratosphere, otherwise known as the tropopause, should rise as a consequence of greenhouse warming. This has been observed [8]. This also contradicts the hypothesis that the earth is warming because of solar activity.6. ....A closer look at the downward radiation finds more heat returning at CO2 wavelengths, leading to the conclusion that "this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming." [9] [10]The resolution is affirmed[1] From http://rationalwiki.org... all references for the premises are within that[2] http://www.skepticalscience.com...[3] http://www.ldeo.columbia.edu...[4] http://www.esrl.noaa.gov...[5] Ibid[6] http://www.nature.com...[7] http://www.knmi.nl...[8] http://www.math.nyu.edu...[9] http://ams.confex.com...[10] http://www.agu.org...

First of all, what scientists say dis irrelevant, scientists used to think that the earth is flat, and even today they are telling us that GMO's are safe, even though foreign scientists have proven time and time againthat they are in fact not safe. Yet, this is the general concensus. Second of all, in Round 2 you tried to disregard my citation that global tempartures are in fact dropping because "newsmax is a conservative news site," as if someone being a conservative automatically discredits them. So this is prettty much just an ad-hominim attack. I could say that because all your citations are highly liberal that they are false. Either way, you claim that CO2 levels are increasing, which is true, and that tempartures are increasing, which is partialy true. But you are yet to prove that these temparture increases are caused by CO2 emmissions. I could say that since 1700 the number of Pirates on the high seas have decreased while global warming has increased, therefor pirates reduce the global temparture. Also do the math, if 3.25% of CO2 emmissions are man made, and 0.04% of ouratmosphere is CO2, {1} then the global temparture can only increase by 0.0013% as a result of CO2 emmissions. Mathmatically speaking, it makes no sense that such a small influence on the atmosphere can cause gobal warming. And look at this graph: It looks like the tempartures are increasing t a rapid rate, but if you accountfor the highest temparture anomaly we have is less than 1 degree celcius, and that it has developed over 76 years, then the idea of global warming being a threat to humanity is shewn to be completely absurd. {1}. https://en.wikipedia.org...

I need to urge Pro to read the sources he/she is citing a bit more carefully before just throwing them into a debate. Beyond the fact that I thoroughly disproved his/her contention that their facts are all from Tesla whose stance is one suggesting "Man-Made Global Warming Isn't Real", they have actually cited sources that say the exact opposite of what they are trying to prove. The other sources, as I describe below, are simply not valid scientific sources in any sense of the term. Especially given that BoP is on Pro, he/she should have to combat my claims with counterclaims from equally, if not superior sources. Rather, they have utilized highly-contested articles from non-scientific sources, some of which are explicitly labeled "opinions" rather than fact.For example, Pro's first source about "WWII/Greenhouse Gasses" is actually titled: Climate myths: The cooling after 1940 shows CO2 does not cause warming. Emphasis on myths. The article is all about the fact that this argument is in no way true. It specifically states that, "The sudden drop in temperatures in 1945 now appears to be an artifact of a switch from using mainly US ships to collect sea surface temperature data to using mainly UK ships. The two fleets used a different method. The temperature record is currently being updated to reflect this bias." This shows that, not only does Pro's claim have no standing because the statistic is actually a result of changing methodology, but they are actually attempting to cite new sources (since their original ones were copied and pasted from a Tesla forum) which either contradict previous arguments or are based on non-scientific, opinion-based, vastly-refuted claims.The source they cite for the "0.7 - 0.9"C increase in the average global temperature" is a 13-page long, fairly technical document which I actually took the time to read. The only time the numbers 0.7 and 0.9 even occur is in a section titled, "2. The importance of data quality and consistency when studying extremes." This section states, among other things, "Nicholls (1996) observed that a major problem undermining our ability to determine whether extreme weather and climate events were changing was that it is more difficult to maintain the long-term homogeneity of observations required to observe changes in extremes, compared to monitoring changes in means of variables. Inhomogeneities affecting station records can most commonly be introduced through site moves, changes in instrumentation, changes in local site conditions (through urbanization for example), or changes in observing practices." This section is about bringing into question the integrity of the very data Pro is attempting to cite. Furthermore, this section actually discusses the "Monthly minimum value of daily min temperature" and in no way speaks to the "average global temperature" as suggested by Pro.Regarding Pro's discussion of the myth of receding glaciers, I should point out first that the article is from 6 years ago, second that it is from the Daily Mail as opposed to the actual scientific sources I provided, and third, only covers the change over one year. Even though the artic sea ice may have increased over this one year, it was still at far lower than average levels. Also, the IPCC did not hold the crisis meeting that was alleged. That is a complete fabrication. The IPCC actually directly came out to state how terrible of a source of information this specific article was:"The UN’s climate science body has rejected claims in the Mail on Sunday newspaper that it plans to hold a crisis meeting to discuss the impending release of its latest major report. In an article labelled ‘Global cooling‘ journalist David Rose said that the growth in Arctic ice was proof of a worldwide global warming scam, and that the predictions of the current climate models were “gravely flawed”. Rose said that leaked reports showed that governments were demanding 1,500 changes to the Summary for Policy makers, as it failed to adequately explain the recent “pause” in global warming. As a result, he said, the IPCC was calling a crisis meeting to deal with the “revelations”. “Contrary to the articles the IPCC is not holding any crisis meeting,” it said in a statement. “The IPCC will convene a plenary session to finalize the Working Group I contribution to the IPCC’s Fifth Assessment Report, in line with its normal procedures, in Stockholm on 23-26 September 2013. “The session has been scheduled for several years and this timetable has been repeatedly publicized by the IPCC.”Pro's article from TheHill.com stating that there is "no real scientific proof" regarding the rise in greenhouse gases is actually an OpEd piece contributed by a seismologist/volcanolgist. In no way is this an actual corroborated scientific source, nor was it even contributed by the type of expert who could refute the plethora of evidence I've provided.Pro's citation of an article about the sun being responsible for a great share of climate change starts with the sentence "In the last 35 years of global warming, the sun has shown a slight cooling trend. Sun and climate have been going in opposite directions." It is an article debunking the exact myth that Pro is trying to perpetuate with their argument. Again, I'm not sure Pro actually read this.Finally, regarding the petition by "scientists", I urge voters to take a closer look. First of all, this petition is over 10 years old. A more "2013 peer-reviewed study evaluated 10,306 scientists to confirm that over 97 percent climate scientists agree, and over 97 percent of scientific articles find that global warming is real and largely caused by humans." Second of all, this petition required no actual proof that the signatories had the credentials they claimed. Third, and perhaps most importantly, many of the signatories in no way were qualified to give factual, unbiased opinions on the matter. Surely those who are best suited to make judgments here are climatologists, meteorologists, agencies like NASA, etc. (all of which are the type I provided). Here are just a few examples of the qualifications of those signatories on Pro's outdated petition, for which I have already provided a more recent, peer-reviewed counter:- Wilbur A. Aanes specializes in veterinary and animal surgery.- Ralph F. Abate specializes in bridge design - Ursula K. Abbott is an avian geneticist - Dirk Den Baars deals in the exploring and mining of copper and precious metals- P. S. Gaal works with the transport properties of materialsThese are just a select few of the hundreds (if not thousands) of scientists who signed this petition who were actually in no way qualified to do so. To restate: This petition is old and outdated I have provided a more recent, peer-reviewed, established petition which directly counters Pro's claim The signatories on Pro's petition are largely unqualified to opine on the matter To summarize this round's argument: Pro initially stated that Tesla was their source for all of their facts. Actually, their claims were all copied and pasted from a forum to which anyone can post. Pro claimed that Tesla's stance was one in line with his/hers, but did nothing to counter my proof that their stance was just the opposite Pro attempted to find new sources to support the points he/she found on the Tesla forum, but ultimately used ones that either proved exactly the opposite of what they were trying to say or were from non-scientific, opinion-based, unqualified sources It is clear that Pro did not read many of these sources as the claims he/she seems to think some of them prove are actually the description of the very myth they debunk

First off, my opponent did not refute my arguments, and completely dropped my most conclusive argument (the DDO global warming opinion page samples). He copy and pasted an article from http://www.redorbit.com...Con's only commentary on this article was "So as you can see that the debate on man-made GW would be useless and the debate should be on weather or not GW exists as we currently have it."The entire article was about how man-made global warming doesn't exist, or is greatly exaggerated, but the author agrees global warming exists. I completely fail to see how this doesn't help my side, as the 'big issue' in this article is man-made global warming, NOT global warming in general. This shows Con's complete lack of understanding on this issueCon then goes on to say "It's too difficult to change things," citing examples of how hard it would be to implement the resolution. This is not a valid argument because it doesn't attempt to analyze the situation. He fails to show that the long and difficult process he described somehow means that the costs outweigh the benefits. The resolution is not trivial, because as it stands, the big issue (global warming exists) is a complete failure of a prompt. It fails to provide clear results because people are too interested in expressing their opinion that man-made global warming exists as seen by the samples in my round one. People shouldn't have to take multiple levels of thought just to 'guess' what someone's opinion on an issue is. I mean, I could vote Con to the prompt global warming exists, assuming everyone else assumes that I assume it means 'man-made global warming exists'. However, another person might assume that I'm ignorant because I don't think global warming exists, when really I do. In conclusion, Debate.org should change the "global warming exists" big issue to "Man-made global warming exists" to present a prompt that represents the opinion that the members of debate.org actually want to share, as seen by the comments on http://www.debate.org......

My case is essentially a counter case to my opponents, so it refutes his arguments in and of itself. 1. Global warming, true?Much of the data that claims the world is heating is actually unreliable, the classic examples (cited in most global warming editorials) is the ground heaters that show massive increases, yet the funny thing is they are unreliable. First, these scanners started seeing heat at certain times, mainly around 2000. At the same time, many of these stations where previously recording no change. But in 2000, many of the recorders where moved or things where built. Many where found like this. One started seeing increased temperatures, BUT the time it saw an increase is when an are conditioner was installed next to it. [1] Now this is a problem as the air conditioner emits hot air, hence the increases in these modules can be linked to the air conditioner. Many of the recorders used where moved into urban areas when previously where rooted in the suburbs. They saw an increase, obviously, they installed them next to roads, asphalt reflects heat, metal buildings, same problems as roads, and then again a lot near air conditioners. A kid could see the problems with this. Other stations saw growth if they where rooted in suburbs, then the suburbs expanded in population, more houses roads etc. [2] As we can see this has serious problems as these highly cited materials fall into one basic problem: The extra asphalt, man made heating objects therefore emit heat near the censors confounding the result, hence there is a likely hood many of the stats you cite are, well, unreliable.Further many of the large studies that show global warming are highly exaggerated, and have been found of fraud accounts. Hence the data my opponent cites is data, but whether or not the data is fabricated is another question. [3]89% of global warming detectors failed to meet accuracy standards due to the reasons above. [8]Quote:" The southern hemisphere of the earth has been generally cooling for the past fifty years, Hundreds of years of data show that temperature rises precede increase in CO2 levels, rather than following them, Ice cover at the north and south pole is growing, which results in more glaciers breaking away Throughout the 20th Century, temperatures have been rising on other planets in our solar system – including Mars, Jupiter, Pluto, and Triton, Neptune's largest moon – where few people drive SUVs. This clearly points to increased solar activity as the cause of global warming on the Earth, rather than any human activity." [10] http://a-sceptical-mind.com... (graphs)My graphs aren't posting anymore, its really annoying, is it like this for everybody? I cant ask Ima for cnfidnetial reasons. 2. Polar ice is expanding We can see from data in Greenland that the ice and snow is actually expanding, not decreasing like Al Gore would claim. As we can see:"Though the ice may be melting around the edges of the Greenland Icecap in recent years during the warm mode of the AMO much as it did during the last warm phase in the 1930s to 1950s, snow and ice levels continue to rise in most of the interior. Johannessen in 2005 estimated an annual net increase of ice by 2 inches a year." [4]Cold war satellites (during time of their function), find that the ice is expanding continually in Greenland, and not decreasing. These stations first received 4 feet of snow, per fall, but in 2006 many of the stations where semi-burried by the snow. The site, formerly alive, is now buried in snow, while greenland ice expands. [5] Now what about overall arctic ice volume? Using US navy data the volume of the ice is increasing and the ice is expanding. [6] "The blink map above shows the change in ice thickness from May 27, 2008 to May 27, 2010. As you can see, there has been a large increase in the area of ice more than two metres thick – turquoise, green, yellow and red. Much of the thin (blue and purple) ice has been replaced by thicker ice." [6]So the thin ice is being defeated, this implies that the ice is getting thicker, this requires colder temperatures, this is an "arrow to the knee" for global warming proponents. How can ice get thicker under warmer temperatures, and how can formerly thin ice get thicker? 3. Global cooling? Now, this is generally pushed to the side in most climate change debates. Well yaddy blah blah blank my liberal science teacher said X. People are mainly going of knee jerk reactions look towards the "majority". Ice in the caps are one way both sides look at the global warming debacle. New data has come to light, we see the earth is no longer "warming", assuming those faulty data sets are correct, but cooling. [7] Now if the things near metal buildings are seeing cooling, this means the earth must be REALLY cooling down to show a decrease. "As Robert Felix just reported in his authoritative iceagenow.com, on various days is June of 2009 there were record low temperatures in 18 states; record low temperatures in 15 states; record low temperatures in 24 states; record low temperatures in 11 states; record low max temperatures in 20 states; record low temperatures in seven states; and record low temperatures in 10 states." [8]4. Even if the earth is warming, it may be natural. http://www.forbes.com... (page two graph)Due to the predicatable fluctuations, we can assume we could predict the cycles and it also shows that global warmign is also caused by a natural cause. Also:http://www.isil.org... (half way down graph[s])This also shows the earths temperture is constantly changing, and we can assume it is a natural fluctuation. With this data, the resolution is negated as even if you prove the global wamring scare, you need to explain the natura fluctuations which easily explain it. If global warmign exists, the governments CANT do anything to stop natural cycles, hence it would be a waste of reasources. 5. Economic harms of regulations First if we assume humans create this phenomona, we must ask what is the cause? The most common claim is human CO2 and oil usage, natural gas etc. But these regulations DO harm the economy. Many of tese regulations are huge costs to buisness, this is hard on them as now they must eiher give up or find ways to compensate (fire workers, or declare bankrupsy), and then no body is helped. These regulations hurt buisness by raising costs, and higher costs to buisness hurt the companies, econ 101. Further, many of these regulations outsoruce jobs for the reason above, or actually make it impossible to do X here, so they do X in china as they can actually do stuff there. One perfect regulaton is the congress' plan to regulate 85% of energy, this harms big time. It is estimated to lease 85% of our energy, and prevent them from drilling on areas that could sustain us from Saudi Arabias imports for 30 years. [9] So these regulations FORCE other countries to take our supplies, well not take, but replace and indirectly take out jobs. Sorry, tese regulaitosn hurt us. CONCLUSION: My case disproves global warming claims, and proves if global warming occurs it is likely natural, hence if it doesn't exist its a waste of time, if it does exist but is natural its a waste of time, if the earth is cooling it is a waste of time, and if it hurts the economy it is one colstly downside. My case esentially refutes my opponents, and I used facts. I urge a CON vote. _________[1] http://bit.ly... [2] http://bit.ly... [3] http://onforb.es... [4] http://bit.ly... [5] http://bit.ly... [6] http://bit.ly... [7] http://on.wsj.com... [8] http://bit.ly... [9] http://bit.ly... [10] http://bit.ly...

To adress your argument, never in this 4.5 billion year history has the temperature climbed this quickly before. In 650,000 years the CO2 levels have never been this high (source: https://climate.nasa.gov...) despite 7 cycles of warming and cooling periods In that time. The introduction of CO2 from humans, however small that may be, has shifted the balance that Nature has held over the 650,000 years, and plants and other "Carbon Sinks" can no longer absorb enough CO2 to prevent the collection of greenhouse gases in the atmosphere. I would like to ask you a question, if global warming is a hoax, like you claim it to be, why would the government 'waste' $32.5 billion on solving the issue.

I would first like to start with the science community. A large and growing number of distinguished scientists and engineers do not agree that global warming is occurring and we do not need to change anything to prevent it. Nobel Prize winning physicist Ivar Giaever publicly resigned from the American Physical Society with a letter stating that he could not live with the APS policy that "global warming is occurring." Much of the funding for the study of the climate comes from pro-warming sources. So much of the publicity and funding of environmental science community makes it seems like global warming is real and hurting everyone everywhere every day. Now I would like to address greenhouse gases. In an article by the New Zealand Climate Science Coalition, they talked to Dr. Jim Renwick and Dr. David Wratt who are lead authors for the IPCC (Intergovernmental Panel on Climate Change) who say that "the earth has not warmed for about 10 years. Yet the government still say that man-made global warming is real and dangerous... But the temperature records say it isn't happening. CO2 is a harmless gas that promotes plant growth and reduces desertification. Ian Plimer, Professor of Geology at the University of Adelaide, says "During the Earth's history, there have been six great ice ages and each of these ice ages started when the atmospheric CO2 content was higher than now, showing that CO2 in the past has not driven global warming. Ice cores show that temperature increases some 800 years before CO2 increases, hence temperature drives the release of CO2 from the oceans into the atmosphere. This is the inverse of the current populist view that CO2 drives global warming. Next, I would like to talk about indicators of the environment. People claim that glaciers are melting and raising sea levels above normal rates extremely. Well, glaciers around the world are continuously advancing and retreating with a general pattern of retreat since the end of the Little Ice Age. There is no evidence of a increased rate of melting overall since CO2 levels rose above their pre-industrial levels, suggesting CO2 is not responsible for glaciers melting. Sea ice area and extent have continued to increase around Antarctica over the past few decades. The mean rate of global sea level has not accelerated over the recent past. Sea levels has been rising for thousands of years and continues at about one inch per decade. Various non-thermometer sources such as tree rings, ocean and lake sediments, ice cores, stalagmites, support an absence of warming. Coral data also show no pronounced warming trend of the sea surface. In fact, according to 30,000 measuring stations around the world confirm a trend that temperatures have not risen since 1997. In a study by Berkeley, it confirmed that marine atmosphere shows no warming. People may talk about the recent extreme weather patterns as examples of global warming. That is wrong. Meteorologists can easily explain these occurrences. The tornadoes and strong rain storms are formed when cold Northern air and warm tropic arm meet, it sets off strong storms that can lead to tornadoes and floods. It has been like this for many years. Hurricanes are also shown to be decreasing. In data taken from 1930s to the 1960s and the 1960s to the 1990s. The data from the 1960s to the 1990s show that there is less hurricane activity than the 1930s to the 1960s data. Any increase in the number of hurricanes can simply by a naturally occurring cycle. So from the information and data we have recieved, it proves that global warming is not occurring. That is why I urge for a Con ballot.

You said: "After the Second World War, their was a huge increase in co2 emission, yet global temperatures fell for decades after that" Over this period, global CO2 emissions were a fraction of current levels. Currently we are emitting over 8000 million tonnes per year. 2012 was the hottest year on record in the continental U.S. Last year beat the previous record holder 1998, by a full 1F. And while 2012 certainly stood out for its high temperatures, it was hardly unusual. The last decade globally has been the hottest in recorded history. (U.S. temperature records go back to 1895.) And the heat has been above average for some time. You talked about how glaciers are melting from pollution not global warming. Well, you may be correct. But does all of the Glaciers that are melting melt from pollution, or is some of it global Warming? You say it's possible that pollution caused them to melt, but that is not saying it's the only explanation. Now your final point, is Global Warming alarmists are liars, because you have disproved their evidence. But did you really? You didn't say: We'll this is how it have happened. You said : this is how it MAY have happened. I may say: The reason is because people are destroying the ice with ice picks. Well that's possible, but yet still not a solid explanation. Thanks.

Links Merely showing a website claiming it 'debunks' skeptics is not an argument. You should explain what the links describe and post them here. I argue with my opponent, not a website.A few things I agree with my opponent:1. It has warmed2. CO2 increased over the period of time that it warmed Things we don't agree about:3. CO2 caused the warming My opponent must prove that CO2 causes the modern warming period--this means proving causation, not correlation (and even the correlation is weak). Ice caps melting (doomed is NOT a scientific term) does not prove that manmade CO2 has produced the warming. It only proves that we have warmed--a premise which I agree with. But the fact is, warming existing does not prove that the warming was manmade. My opponent must show that CO2 causes the warming, not that warming exists. 1. Sun and volcanoes I agree volcanoes do not cause the modern warming period. I do, however, think the sun causes the majority of the modern warming. Arguing that the sun causes 1/3 of the warming is almost a concession. The study my opponent cites, although claiming greenhouse gasses cause much of the warming, did concede that, "the current climate models underestimate the observed climate response to solar forcing over thetwentieth century as a whole, indicating that the climate system has a greater sensitivity to solar forcing than do models" [1. http://climate.envsci.rutgers.edu...]. Indeed, the models do not adequatley account for solar forcing. In fact, if they cannot account for basic TSI, then how can they account for other factors which the sun accounts for? Another study which looks at many types of solar impact--TSI, cosmic rays, etc has found that the sun has likely contributed to 66% of the recent warming, and maybe more [2. http://heartland.org...]. Another study has found that the sun is underrepresented in the models by a factor of 6 [3. http://arxiv.org...]. There is a strong body of research which demonstrates that the sun has caused a significant portion of the modern warming. TSI, luminosity, and many other solar effects are increasing. This means the current warming, based on a solar theory, is to be expected. Research has found strong modern correlations with temperature and solar luminosity. Overall, this line of research finds that the sun has been responsible for at least half of the modern warming, and maybe even more. Correlations have also been found with solar magnetic activity. Now, skeptics are unlike alarmists: they actually accept there is a margin of error (like a good scientist should). These skeptic reports have admitted that, when it comes to the sun, some of the mechanisms remain undescribed--unknown--but still maintain the overall position that the weight of the evidence suggests a strong solar forcing [4. Michaels, Patrick J. Shattered Consensus]. The fact is, we cannot rule out anything. The climate is a complex system and alarmists claim to know much more about it than they actually do. The sun, at this point in the research, is likely the main culprit behind global warming: likely over 50%. And even the 1/3 my opponent claims would be near concession: as 1/3 is very significant, and if we include other natural factors (PDO, AMO, ENSO) and other solar factors (like GCR's), the overall natural effect from global warming does in fact seem to approach--or exceed--the 50% mark. As Dr. Roy Spencer explains, "if the climate system is insensitive, this means that the extra carbon dioxide we pump into the atmosphere is not enough to cause the observed warming over the last 100 years — some natural mechanism must be involved." [5. http://www.drroyspencer.com...]. 2. Appeals to Authority My opponent cited multiple scientific organizations which support AGW theory. This is merely an appeal to authority. Science is not done by consensus. Many of these organizations--namely, the NAS--supported global cooling theory in the 1970s. As did many of the leaders of those organization's leaders. Although many people criticize the skeptic NIPCC, they have been extensivley cited in the academic literature and do have a body of scientists working with them on each of their reports [6. http://climatechangereconsidered.org...]. Their reports have also been hailed and supported by the Chinese Academy of Sciences [7. http://wattsupwiththat.com...]. Further, scientific polls of scientists do not always show a strong consensus. Geologists do, in fact, study climate change. They understand the past and are what are often called paleoclimatologists. The American Association of Petroleum Geologists has stated that "The earth’s climate is constantly changing owing to natural variability in earth processes." A survey of geologists has found that about 68% of geologists remain skeptical of AGW theory, and only 26% think it is due to man made causes. Geologists remain skeptical because the paleo-climactic proof for AGW is very weak, at best, and the evidence tends to show that CO2 is not the main driver of climate over geological epochs [8. http://www.paulmacrae.com...]. 3. Rule things out? We cannot rule anything out, thats not science. We know that, for example, creatonism is very very unlikely, and that evolution is likely true, but we cannot simply rule creationism out as evolution still is not a 'law' (it is almost impossible to make something a 'law'. And to clarify, I support the theory of evolution). But the evidence for AGW is nowhere NEAR as solid as it is for evolution or old earth, and even then we cant say the chances for creationism are 0%, only infinitesimally small. When it comes to AGW, I see a complex climate system we do not know much about: and what we do know about it, natural variations can almost alone explain the modern warm period. The fact is, we cannot rule anything in this area 100% out, and in fact many natural variations seem to explain the modern warming much better than man. Do I deny CO2 has some effect on warming? Absolutley not. However I do argue that its effects are much smaller than 50%, and natural variations are the main cause of the modern warm period.

No, your first two references do not show anything.The first one, about that Maurice guy, does not provide any kind of sourcing, and therefore cannot be taken seriously. It's basically just a bunch of had hominem calling him and his sister marxists and what not, with the whole point being "he created all of global warming in order to make a new world order". Yeah.The second one, in which "1000" (It's actually 24) scientists are quoted as saying that they don't believe in climate science. This, of course, is just a massive appeal to authority fallacy.False InformationWhat?! You know you can't just say "that's not true" and then have something not be true, right?Climate change poses a threat to humanityHere: http://www.greenpeace.org...Here: http://www.greenpeace.org...;Aaaand here: http://www.who.int...;Earth Self RegulatesWhere'd you get that from? The graphs obviously show that the temperature has not stayed level, so this point is just misinformation."Hockey stick is broken" No it isn't, ya silly: https://www.skepticalscience.com..."CO2 increase doesn't affect temperature." *sigh* Graphs.What even is this point. It talks about radiation, then some arbitrary distance, then shortening that arbitrary difference, then talks about how distance =/= temperature (reasonable), and finally throws out some arbitrary percentage to top it all off.


Question: Is mankind's impact the main driver of alterations in the global climate?

Climate Change and Human Influence
Case Point A: Climate Shift is a Real Phenomenon
The scientific consensus is clear that climate shift is real and primarily human-induced. Carbon dioxide and other global warming pollutants are accumulating in the atmosphere, trapping the sun's heat and causing the planet to warm up. Over the past 50 years, the average global temperature has increased at the fastest rate in recorded history. Scientists predict that unless we curb the emissions that cause climate change, average U.S. temperatures could rise by 3 to 9 degrees by the end of the century. (1)(2)(3)(4)(5)(6)(7)
Case Point B: Climate Shift is Influenced by Human Activity
The scientific consensus is overwhelming that climate shift is influenced by human activity. The United States Global Change Research Program, which includes the Department of Defense, NASA, National Science Foundation, and other government agencies, has stated that "global warming is unequivocal and primarily human-induced" and that "climate changes are underway in the United States and are projected to grow." (3) The climate change denial machine has been working hard to discredit the latest UN Intergovernmental Panel on Climate Change (IPCC) report, which confirms that climate change is occurring and that human activity is primarily responsible. (5) Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities, and most of the leading scientific organizations worldwide have issued public statements endorsing this position. (6)
Sub Point 1: Carbon Emissions are a Major Cause and a Product of Humanity
The only way to explain the pattern of climate shift is to include the effect of greenhouse gases (GHGs) emitted by humans. (2) Most climate scientists agree that the main cause of the current global warming trend is human expansion of the "greenhouse effect" - warming that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere block heat from escaping. Long-lived gases, remaining semi-permanently in the atmosphere, which do not respond physically or chemically to changes in temperature, are described as "forcing" climate change. (7) Scientists agree that humanity has altered the balance of greenhouse gases on the earth, which is a direct major cause of climate shift.
Case Point C: Climate Shift Threatens the Future, and is Therefore a Legitimate Concern of Those Who Care About the Future of Humanity
Global climate change leads to increased temperatures, changing landscapes, a higher number of drought

Thanks Pro for concise and focused argument.General limitations of Climate modellingIn perfect scenario, we would have simple deterministic mathematical model to simulate deterministic phenomena on which we can run multiple experiments with controlled conditions in order to validate the model. While for example engineering simulations can comply with such scenario to some extent, complex phenomena in economic, social or climate sciences are another story. We don't have enough beforehand knowledge about every important climate feedback so we in fact estimate such feedback's with the model itself based on its output compared to measurements. But unless we know all other forcing that can influence output in similar way, we won't get good estimate of the parameter we look for.For example Koutsoyiannis[1] or Tennekes[2] (extending on Poper and Lorenz) challenge the notion that complex models could ever be reliable according to their nature. "Theories that are complex may become untestable, even if they happen to be true."[2] etc.If we look at QT's definition of GCM, it is clear that to fulfill their purpose, those models must have the structure of forcings and feedbacks right. We won't get reliable "scenario predictions", no matter how lucky we are in predicting aggregated mean temperature if the true causes are different then we thought.What is the reliability of current GCMs in scientists eyes?"We compare the output of various climate models to temperature and precipitation observations at 55 points around the globe... Besides confirming the findings of a previous assessment study that model projections at point scale are poor, results show that the spatially integrated projections are also poor."[1]"We examine tropospheric temperature trends of 67 runs from 22 ‘Climate of the 20th Century' model simulations and try to reconcile them with the best available updated observations (in the tropics during the satellite era). Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by more than twice the uncertainty of the model mean."[3]"These weaknesses combine to make GCM-based predictions too uncertain to be used as the bases for public policy responses related to future climate changes." [4]"So there has been a large activity to bring models and observations into agreement, strangely only by adjusting the measurements instead of adjusting the models. "[5]Even Kevin Trenberth (from the Mann et al. group) now acknowledges many of the GCM's troubles in his paper "More knowledge, less certainty"[6] publicly."The scientific literature is filled with studies documenting the inability of even the most advanced GCMs to accurately model radiation, clouds, and precipitation."[7]For those interested, NIPCC report [7] and their topical updates [8] provide comprehensive information about studies dealing with GCM reliability.RefutationAs you put it, Hansen's predictions look totally perfect and within 100th of degree of Celsius. Lets examine the claim. "Dr. Jim's 1988 projections weren't looking so good, so he dropped an apple in the middle of his oranges. The red line is land only temperatures, but his projections were for global temperatures."[9] Let us also compare it with satellite [10] and other [11] data. Now suppose I made highly oscillating prediction. At some points in time, my prediction would be always spot on as it would cross the real data. Look back at the figures. Where is this precision from 2006 until now, or in early nineties? Also note that curve C assumes "emissions drastically reduced" in 1990 [10,11]. I therefore call this conduct a fallacy of cherry-picking.On top of that, Hansen is known for not so transparent temperature data manipulation.[12,13]Dessler's assumptions are refuted by Spencer's satellite observations [14], supporting rather Lindzen's hypothesis:"Our measured sensitivity of total (SW + LW) cloud radiative forcing to tropospheric temperature is -6.1 W *m^-2 K^-1... This decrease in ice cloud coverage is nominally supportive of Lindzen's 'infrared iris' hypothesis.""This is exactly opposite of the way all climate models behave," as Spencer put it in his own words in [15]. (technical note: Don't take the whole video as extension of my argument. Its used only as source of the quote in 6:19 and for information purpose as I acknowledge I must make my argument myself on this page within its limitations.)Now lets see the warming troposphere, because it was predicted it would be significantly warmed by CO2 forcing. See figures 3.4.1 and 3.4.2 for PCM model prediction and 3.4.3 for radiosondes.Updated study [17], taking in account errors stated by Pro, supports overall warming trend in troposphere of +0.052 ± 0.07 K per decade (while RSS temperature is somewhat higher then other methods, but much less then models).That is in good agreement what the figure 3.4.3, but in complete disagreement with figure 3.4.2 (also note the scales). The problem is not whether the troposphere warmed, but how much it warmed (1.2 °C at hotspot vs 0-0.3°C) and how different layers warmed relative to each other. The model predicted much stronger warming in troposphere then on surface, but that is not true. It means that model is wrong about GHG forcing or feedbacks in troposphere.ConclusionModels may be useful in furthering our knowledge of the problem, mostly by showing us what our assumptions really mean. If we are humble enough and learn from comparing our assumptions to measurements, we can learn from our mistakes.But the climate models fail if used as defined by Pro.[1] http://www.tandfonline.com... [2] http://ff.org...[3] http://www.pas.rochester.edu... [4] http://www.ncpa.org... [5] http://hockeyschtick.blogspot.com... [6] http://www.nature.com... [7] http://www.nipccreport.org... [8] http://www.nipccreport.org... [9] http://sppiblog.org... [10] http://www.climate-skeptic.com... [11] http://rankexploits.com... [12] http://stevengoddard.wordpress.com... [13] http://www.omsj.org... [14] http://www.drroyspencer.com... [15] Video: "Why the IPCC Models...." http://www.youtube.com... [16] http://www.nipccreport.org..., pages 106-108[17] https://www.cfa.harvard.edu...

Well I see youre only 14 so I will be nicer that usual- now you dont REALLY make 150K per year do you? : ) lets look at your statements #1 I strongly disagree with the pro's argument. Al Gore has absolutely no reason to lie about this. The pro states that he does this to curtail fossil fuel usage. YES. That is the entire point. But is this evil??? Not at all. And it doesn't benefit him personally at all. He and other Global Warming Believers are doing this simply to save mankind, not to benefit themselves. Are you kidding ? Al Gore is making millions of dollars jetting around the world, and he picked up a nobel prize as well. He flies around in jets- giving off tons of emissions his house uses like 10 times as much energy as his neighbors He is a total hypocrite , and is loving the limelight as he has become the grand poobah preacher of this new religion - and thats what it is- a religion the UK has furthermore said that there are at least 9 factual errors in "An Inconvenient Truth" http://www.timesonline.co.uk... summary : A High Court judge today ruled that An Inconvenient Truth can be distributed to every school in the country but only if it comes with a note explaining nine scientific errors in Al Gore's Oscar-winning film. The Government had pledged to send thousands of copies of the film to schools across the country, but a Kent father challenged that policy saying it would "brainwash" children. BREAK Now we all care about the earth, and I sell solar systems for a living, i hike and bike and kayak and am totally concerned about the planet. I also KNOW we need to get off fossil fuels for national security. We need to use hydrogen for that- I have been pushing that for 20 years But al Gore and the global warming crowd are NOT advocating solar hydrogen- they are pushing taxes and control so they can get rich and accrue power here is you other point Also, their is OVERWHELMINGLY HIGH SUPPORT AMONG THE WORLD THAT GLOBAL WARMING IS REAL. The majority of the U.S. gov't, The Pope, Canada, Austrailia, and almost all of Europe agree that global warming is set to drastically hurt and even destroy the earth. The argument that global warming exists goes much farther than just Al Gore. Also, the argument that it is false is only held by a few American politicians and large oil companies that have been known to mislead the government. Well, you obviously watch the news and all that you said is repreating what they say, which is REALLY SCARY and BELIEVABLE isnt it? Well , you mention the pope here, who I admire greatly. lets see what the pope had to say today about Global Warming : http://www.dailymail.co.uk... excerpt from article : Pope Benedict XVI has launched a surprise attack on climate change prophets of doom, warning them that any solutions to global warming must be based on firm evidence and not on dubious ideology. The leader of more than a billion Roman Catholics suggested that fears over man-made emissions melting the ice caps and causing a wave of unprecedented disasters were nothing more than scare-mongering. Well now, the Pope, a man of incredible integrity, agrees with those of us who see it is scare mongering. What I would like you to learn is that not everything that people tell you is true. Especially DEMOCRAT TYPES. they LIE ALL THE TIME . cheers Solarman

I experienced slight formatting difficulties with this and apologise for any confusion that may result.I'm sure you've heard it all before: rising global temperatures, melting glaciers around the poles, greenhouse gases, deforestation, rising sea levels and advanced mutation of various exotic diseases have all been in the media spotlight at some time over the past decade. Multiple influential politicians like Al Gore have all spoken out in favor of environmental action. However, over the course of my research, I have discovered that most climatologists don't seem to agree. I will refute these phenomena in order by citing facts from various sources. Because this is such a scientifically oriented topic, I have stayed away from emotional statements to the best of my ability and encourage my opponent to do the same.I should break now to define some key terms:Global warming is the theory that increased levels of carbon dioxide and certain other gases are causing an increase in the average temperature of the earth's atmosphere due to the greenhouse effect. The Kyoto Protocol sets binding targets for "37 industrialized targets and the European Community for reducing GHG [Greenhouse Gas] emissions... By five percent against 1990 levels... [between] 2008-2012. (http://unfccc.int...)."If the Kyoto Protocol is to be quoted in this debate, I request that the copy at http://unfccc.int... be used for our mutual convenience.Back to the arguments (key statements have been written in bold):Firstly, let me refute the "major Antarctic melting sea ice problem" statement. Before I do so, I must establish whether or not we agree on the following statements: that the Antarctic Peninsula encompasses approx. 2% of the continent, and that Antarctica contains 90% of the world's ice (http://www.gma.org...). Please reply to this in your response. Now to the refutation: according to a report in the Science Magazine in an article titled "Interpretation of Recent Southern Hemisphere Climate Change" by Thompson, D.W.J., and Solomon, S., 2002, Antarctic peninsula has warmed several degrees while interior has cooled somewhat. Ice shelves have retreated but sea ice has increased . The link to the abstract can be found here: http://www.sciencemag.org... Unfortunately, you have to sign up for the full article, something I haven't done. The article found at http://www.daycreek.com... conclusively proves that the earth was warmer than it is today during the last four interglacials, dating back 420,000 years. http://journals.ametsoc.org...(2000)013%3C1674%3AVATIAS%3E2.0.CO%3B2 references a slight cooling trend over the past 20 years, according to a consensus between satellite and ground stations. Ian Joughin and Slawek Tulaczyk used "ice-flow velocity measurements from synthetic aperture radar to reassess the mass balance of the Ross Ice Streams, West Antarctica... find strong evidence for ice-sheet growth (+26.8 gigatons per year)." Their findings can be found at http://www.sciencemag.org.... "Climate models generally predict ampliﬁed warming in polar regions as observed in Antarctica’speninsula region over the second half of the 20th century. Although previous reports suggest slight recent continental warming ,our spatial analysis of Antarctic meteorological data demonstrates a net cooling on the Antarctic continent between 1966 and 2000, particularly during summer and autumn. The McMurdo Dry Valleys have cooled by 0.7 8C per decade between 1986 and 2000, with similar pronounced seasonal trends." http://atoc.colorado.edu... Now for the carbon dioxide: Carbon dioxide levels have grown only seventy parts per million in the past 50 years. (http://www.esrl.noaa.gov...) In the scheme of Kyoto, which decreases CO2 levels by 5% of 1990 levels (17.5ppm), this shows that such implementation would have an insignificant impact on the atmosphere, decreasing levels by only around 3% of 2010 levels (same source). The margin of error for this measurement, according to the same source, is 0.11 ppm. According to http://www.futurepundit.com..., increasing CO2 rates will stimulate plant growth and therefore be beneficial to the human race. Deforestation: Deforestation has not been scientifically tied with global warming. Rising Sea Levels: http://tidesandcurrents.noaa.gov... says that "The mean sea level trend is -1.74 millimeters/year with a 95% confidenceinterval of +/- 0.91 mm/yr based on monthly mean sea level data from 1964 to 2006 which is equivalent to a change of -0.57 feet in 100 years." at that station. http://tidesandcurrents.noaa.gov... says that "The mean sea level trend is 0.57 millimeters/year with a 95% confidenceinterval of +/- 0.42 mm/yr based on monthly mean sea level data from 1943 to 2009 which is equivalent to a change of 0.19 feet in 100 years." at that station. http://tidesandcurrents.noaa.gov... says that "The mean sea level trend is 1.64 millimeters/year with a 95% confidenceinterval of +/- 0.80 mm/yr based on monthly mean sea level data from 1937 to 1971 which is equivalent to a change of 0.54 feet in 100 years." Aside from the abovementioned measurements, It has been scientifically proven that sea levels have been rising at roughly the same rate (10-20cm per hundred years, or 4-8 in. every hundred years) for the past 6000 years, and even faster than that beginning at 15000 years ago. (http://www.grida.no...) This rate has not accellerated and many computer models say this trend will be reversed within the next few hundred years. Rising sea levels are clearly not a currently global phenomenon. It would be counter-productive to the purpose of the debate if my opponent references computer models as these contain errors of up to 300% as seen in their failure to predect the large El Nino of 1998. Computer models of weather rarely predict accurately two days from the time of prediction, so assuming accuracy years from the time of prediction is ridiculous.Conclusion:Kyoto and Global Warming Theory Should be Abandoned Unless Impact on Environment is Objectively ProvenAlthough the politically convenient movement is no longer in the global spotlight, we still spend an enormous amount of money on green energy etc. For instance, Obama invested $535 million dollars in the Solyndra which still ended up bankrupt (http://www.time.com...). Considering that all this money is flowing out of the US to prevent a catastrophe that may or may not exist, it is necessary that an objective review of all the past studies on the subject be conducted and further environmental spending be severely reduced if the outcome is determined by the facts cited above. Also considering the evidence regarding the ineffectiveness of the Kyoto Protocol, I belive that the Global Warming Crisis is much exaggerated and funding to prevent this Crisis should be regulated accordingly. Clearly, Global Warming Theories and the Kyoto protocol should be respectively disregarded and annulled.I look forward to your response,ant981228

As I truly do not have enough time over the next two days to fully refute, I will refute your short summary. "Secondly, like I've stated before, humans are adapting and evolving, and they've never stopped. Global warming is just one more thing to adapt to." Now, when is the last time that humans have undergone a major physical change? We have been the same physical form since we transferred from apes to humans. we will not be adapting to any new physical changes. I direct your attention to Web MD, under Apert Syndrome: General Discussion Apert syndrome, also known as acrocephalosyndactyly type I (ACS1), is a rare genetic disorder that is apparent at birth (congenital). The disorder is character-ized by distinctive malformations of the head that lead to distinctive facial features. In addition, the hands and/or feet may be webbed (syndactyly) and in some cases, mental retardation may also be present. Now, you may have a birth defect (to put it nicely). There are other reasons too: Smoking, Finger Birth Defects Linked Pregnant Smokers May Be More Likely to Have Babies With Abnormal Fingers and Toes By Miranda Hitti WebMD Medical NewsReviewed by Louise Chang, MDJan. 11, 2006 -- Women have one more reason not to smoke during pregnancy. Smoking during pregnancy may boost a woman's chances of having a baby with abnormal fingers and toes. Those problems include webbed feet, extra toes or fingers, and missing toes or fingers. This is also abnormal. Now, here is the page of possible syndromes for webbed feet: Smoking, Finger Birth Defects Linked Smoking during pregnancy may boost a woman's chances of having a baby with abnormal fingers and toes...of having a baby with abnormal fingers and toes. Those problems include webbed feet, extra toes or... WebMD Health News Smoking, Finger Birth Defects Linked Smoking during pregnancy may boost a woman's chances of having a baby with abnormal fingers and toes...of having a baby with abnormal fingers and toes. Those problems include webbed feet, extra toes or... WebMD Health News Apert Syndrome Important It is possible that the main title of the report Apert Syndrome is not the name you expected. Please check the synonyms...facial features. In addition, the hands and/or feet may be webbed... WebMD Medical Reference from the National Organization of Rare Disorders Guide to Plastic Surgery An interactive guide to plastic surgery procedures WebMD Health Zone Guide to Plastic Surgery An interactive guide to plastic surgery procedures WebMD Health Zone Chromosome 18,Monosomy 18p Important It is possible that the main title of the report Chromosome 18, Monosomy 18p is not the name you expected. Please check...present. Such findings commonly include a short, webbed neck; a... WebMD Medical Reference from the National Organization of Rare Disorders Ready or Not: The First Trimester WebMD and "The Unofficial Guide to Having a Baby" give you the scoop on the first trimester of your...The limb buds have grown into arms and legs, but the hands and feet are mere ridges. 8 The... WebMD Medical Reference from "The Unofficial Guide to Having a Baby" Reconstructive Surgery Here's a brief overview of reconstructive surgery...back problems or other related health issues; men also undergo breast reduction. Surgeries for feet and hands. This surgery is available for people... WebMD Medical Reference Wet Workout Basics I hate to say, there is nothing here about evolving into water-bound creatures. Thank you and I agaian apologize for not refuting all of your points.

i define the topic to mean: globel warming over the past few decades is a result of human activity. so there

c1. 1) There hasn't been any global warming since 1997: If nothing changes in the next year, we're going to have kids who graduate from high school who will have never seen any "global warming" during their lifetimes. That's right; the temperature of the planet has essentially been flat for 17 years. This isn't a controversial assertion either. Even the former Director of the Climate Research Unit (CRU) of the University of East Anglia, Phil Jones, admits that it's true. Since the planet was cooling from 1940-1975 and the upswing in temperature afterward only lasted 22 years, a 17 year pause is a big deal. It also begs an obvious question: How can we be experiencing global warming if there's no actual "global warming?" 2) There is no scientific consensus that global warming is occurring and caused by man: Questions are not decided by "consensus." In fact, many scientific theories that were once widely believed to be true were made irrelevant by new evidence. Just to name one of many, many examples, in the early seventies, scientists believed global cooling was occurring. However, once the planet started to warm up, they changed their minds. Yet, the primary "scientific" argument for global warming is that there is a "scientific consensus" that it's occurring. Setting aside the fact that's not a scientific argument, even if that ever was true (and it really wasn't), it's certainly not true anymore. Over 31,000 scientists have signed on to a petition saying humans aren't causing global warming. More than 1000 scientists signed on to another report saying there is no global warming at all. There are tens of thousands of well-educated, mainstream scientists who do not agree that global warming is occurring at all and people who share their opinion are taking a position grounded in science. 3) Arctic ice is up 50% since 2012: The loss of Arctic ice has been a big talking point for people who believe global warming is occurring. Some people have even predicted that all of the Arctic ice would melt by now because of global warming. Yet, Arctic ice is up 50% since 2012. How much Arctic ice really matters is an open question since the very limited evidence we have suggests that a few decades ago, there was less ice than there is today, but the same people who thought the drop in ice was noteworthy should at least agree that the increase is important as well. 4) Climate models showing global warming have been wrong over and over: These future projections of what global warming will do to the planet have been based on climate models. Essentially, scientists make assumptions about how much of an impact different factors will have; they guess how much of a change there will be and then they project changes over time. Unfortunately, almost all of these models showing huge temperature gains have turned out to be wrong. Former NASA scientist Dr. Roy Spencer says that climate models used by government agencies to create policies "have failed miserably." Spencer analyzed 90 climate models against surface temperature and satellite temperature data, and found that more than 95 percent of the models "have over-forecast the warming trend since 1979, whether we use their own surface temperature dataset (HadCRUT4), or our satellite dataset of lower tropospheric temperatures (UAH)." There's an old saying in programming that goes, "Garbage in, garbage out." In other words, if the assumptions and data you put into the models are faulty, then the results will be worthless. If the climate models that show a dire impact because of global warming aren't reliable -- and they're not -- then the long term projections they make are meaningless. 5) Predictions about the impact of global warming have already been proven wrong: The debate over global warming has been going on long enough that we've had time to see whether some of the predictions people made about it have panned out in the real world. For example, Al Gore predicted all the Arctic ice would be gone by 2013. In 2005, the Independent ran an article saying that the Artic had entered a death spiral. Scientists fear that the Arctic has now entered an irreversible phase of warming which will accelerate the loss of the polar sea ice that has helped to keep the climate stable for thousands of years....The greatest fear is that the Arctic has reached a "tipping point" beyond which nothing can reverse the continual loss of sea ice and with it the massive land glaciers of Greenland, which will raise sea levels dramatically. Of course, the highway is still there. Meanwhile, Arctic ice is up 50% since 2012. James Hansen of NASA fame predicted that the West Side Highway in New York would be under water by now because of global warming. If the climate models and the predictions about global warming aren't even close to being correct, wouldn't it be more scientific to reject hasty action based on faulty data so that we can further study the issue and find out what's really going on? Rebuttal to physical realities 1. Scientists have only been observing temperature objectively since the 1970's, which proves pro wrong on this point. 2. My opponent provides links to few of his claims, so they should be considered false. 3. "http://nsidc.org...; does not work. (page not found) so that is thrown out. 4. The record is less than 30 years (there were fluctuations until 1980), so I doubt this is any proof. Scientists can tell you how long a star upwards of 50 light-years away will die with more accuracy than telling you next week's weather. (Earth has very unpredictable climate and weather due to large amounts of liquid water.) Short-term warming is not the Earth's climate changing. 5. http://www.globalresearch.ca... (yay canada) 6. There have been 27-year long heat/cold fluctuations since 1428. (link above) 7. Actually, the 1900's are even better proof of this. (link above) 8. Pro has not fulfilled BoP, so it is safe to say that pro cannot prove this topic.

I accept most of the rules of your debate, but do not accept the character limit. Since you didn't respond in time to my comments, but were apparently online during this time, I believe I gave you sufficient time to respond.Since you didn't change the character limit to 10,000 within a half hour despite being online, I will use a google docs if I go over 8,000 characters, but will not go over 10,000 characters. You may do the same if you go over 8,000, but be sure not to go over 10,000 characters. Do you agree to this? If not, I'll just forfeit the debate. Definitions:Anthropogenic: "of, relating to, or resulting from the influence of human beings on nature"[1]I felt the definition of that word may be necessary since it's a large word that many people may not have heard of before, so I defined it for the benefit of the voters.Sources:[1] https://www.merriam-webster.com...

I would first like to apologize for not posting any graphs; my computer's internet is down and I am writing this from my 4G iPad. I will point out the graphs with their respective sources at the appropriate times. Now on to my arguments: I. Various Universal Causes I. i. Cosmic Rays I. i. a. Position Every approximately 135 million years, Earth enters a more populated area of the Milky Way, and as a result, more cosmic rays hit the Earth, which causes cooling. Currently, we are in a less populated area of the Milky Way, which means that less of these cosmic rays will be hitting the Earth, which means less cloud formation, and of course, warming. [1] for the source on this hypothesis. I. i. b The Sun The sun can also cause it: "The implications, if true, had potentially enormous implications for the debate about natural causes of warming. When the sun is very active, it can be thought of as pushing away cosmic rays from the Earth, reducing their incidence. When the sun is less active, we see more cosmic rays. This is fairly well understood. But if Svensmark was correct, it would mean that periods of high solar output should coincide with reduced cloud formation (due to reduced cosmic race incidence), which in turn would have a warming effect on the Earth, since less sunlight would be reflected back into space before hitting the Earth. Here was a theory, then, that would increase the theoretical impact on climate of an active sun, and better explain why solar irradiance changes might be underestimating the effect of solar output changes on climate and temperatures. "[2] "Since he first suggested his hypothesis over a decade and a half ago, Svensmark and other researchers have slowly been putting together research to test it. " The results were: "Scientists found that when shielding was removed and natural cosmic rays allowed to hit the chamber, cloud seeding increased dramatically, and it increased substantially again when additional artificial cosmic rays were added. Svensmark appears to have gotten it right. "[3] Proof here is in the next sub-sub point. I. i. c. The Sun: part II The sun's cycles have a lot to do with temperatures also. "In this chamber, 63 CERN scientists from 17 European and American institutes have done what global warming doomsayers said could never be done — demonstrate that cosmic rays promote the formation of molecules that in Earth's atmosphere can grow and seed clouds, the cloudier and thus cooler it will be. Because the sun's magnetic field controls how many cosmic rays reach Earth's atmosphere (the stronger the sun's magnetic field, the more it shields Earth from incoming cosmic rays from space), the sun determines the temperature on Earth. "[4] "Svensmark matched the data on cosmic rays from the neutron monitor in Climax, Colorado, with the satellite measurements of solar irradiance from 1970 to 1990. Over the period between 1975 and 1989, he found cosmic rays decreased by 1.2 percent annually, amplifying the sun's change in irradiance about four-fold"[5] So, as the sun's activity increases, so does the temperature. Graph 1: View the Correlation between Solar Activity and Temperature in Source 6. This graph clearly shows that temperature goes up and down with solar activity, because an increase in solar activity directly correlates with an increase in average temperature 1-2 years later. I. ii. Rest of the Solar System The Sun clearly is in a warmer phase, because all of the other planets have increasing temperatures as well. "In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide "ice caps" near Mars's south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. "[7] "'Global warming on Neptune's moon Triton as well as Jupiter and Pluto, and now Mars has some [scientists] scratching their heads over what could possibly be in common with the warming of all these planets … Could there be something in common with all the planets in our solar system that might cause them all to warm at the same time? '"[8] Two things can be drawn from this. One, that if other planets are warming, that it is only natural for the Earth to be warming as well. And second, that even if all these planets did have natural causes, then that is a sign of Earth's natural climatic change, instead of man-made. II. Earthly Causes II. i. Ocean Currents Ocean temperature anomalies seem to be rising-along with the temperature. ". .. one can model past temperatures as a linear trend (that started well before CO2 was added in any substantial quantity) and periodic bumps. .. . .. temperatures over the last 100+ years look a lot like a linear trend plus ocean cycle-driven bumps"[2] What is causing all the bumps? : Graph 2: Omitted: The Pacific Decadal Oscillation Has an Enormous Effect on Tempetature in Source 2 II. ii. The 1500-Year Cycle This has to do with a cycle of the climate that can explain the warming. "Through at least the last million years, a moderate 1500-year warm-cold cycle has been superimposed over the longer, stronger Ice Ages and warm interglacials. "[5] Graph 3: 1500-Year Cycle in Source 11 There are two things we can conclude from this graph. First, that up-and-down cycles are normal for the long-term climate. This century's global warming is nothing new. The second thing we can conclude, is that today's global warming is not as bad as the Medieval Warm Period's peak yet, and the Medieval Warm Period was less than the Holocene Maximum Period. "Even more important, the earth is not "the warmest it has ever been. " In fact, the earth was much warmer during the Medieval Warm Period when human agriculture flourished! "[9] "The scientists found evidence that on average, every 1,470 years, plus or minus 500 years, cold, ice-bearing waters, which today circulate around southern Greenland, pushed as far south as Great Britain. "[10] There seems to be a full cycle of up-down-up temperatures of the climate every 1470 years. And this goes as far back as at least 1 million years ago. Currently, we are in an upswing of temperatures, just coming off of the Little Ice Age, the peak to be in a few hundred years, making the peak-to-peak difference between today's global warming and the Medieval Warm Period a little less than 1500 years. So today's Global Warming is a natural, cyclical occurence. Conclusion: And as a final side note, I would like to present this graph that helps disprove the anthropogenic cause theory, regarding again, ocean temperature anomalies: Graph 4: Two 51-Year Periods: Which Is Man and Which Is Mother Nature? Source 2. Sources: [1]: MacRae, Paul: "Alarm: Global Warming-- Facts versus Fears" [2]: . http://www.climate-skeptic.com... [3]: . http://www.forbes.com... [4]: . http://www.eutimes.net... [5]: Singer, S. Fred, and Dennis T. Avery: "Unstoppable Global Warming: Every 1,500 Years" [6]: . http://www.petitionproject.org... [7]: . http://news.nationalgeographic.com... [8]: . http://www.livescience.com... [9]: . http://www.isil.org... [10]: . http://www.sciencedaily.com...

The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere. Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. = 1. The 0.7 - 0.9"C increase in the average global temperature over the last hundred years is entirely consistent with well-established, long-term, natural climate trends. 2. The slight increase in temperature which has been observed since 1900 is entirely consistent with well-established, long-term natural climate cycles 3. It is claimed the average global temperature increased at a dangerously fast rate in the 20th century but the recent rate of average global temperature rise has been between 1 and 2 degrees C per century - within natural rates The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost and average of 281 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 119 billion tons during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade./Glaciers are retreating almost everywhere around the world " including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa. 1. It is myth that receding glaciers are proof of global warming as glaciers have been receding and growing cyclically for many centuries. 2. It is a falsehood that the earth"s poles are warming because that is natural variation and while the western Arctic may be getting somewhat warmer we also see that the Eastern Arctic and Greenland are getting colder. 3. Research goes strongly against claims that CO2-induced global warming would cause catastrophic disintegration of the Greenland and Antarctic Ice Sheets. 4. It is a falsehood that the earth"s poles are warming because that is natural variation and while the western Arctic may be getting somewhat warmer we also see that the Eastern Arctic and Greenland are getting colder Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier. 1. There is strong evidence from solar studies which suggests that the Earth"s current temperature stasis will be followed by climatic cooling over the next few decades Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century. 1. Politicians and activists claim rising sea levels are a direct cause of global warming but sea levels rates have been increasing steadily since the last ice age 10,000 ago. The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. 1. Warmer periods of the Earth"s history came around 800 years before rises in CO2 levels. 2. Throughout the Earth"s history, temperatures have often been warmer than now and CO2 levels have often been higher - more than ten times as high. 3. Significant changes in climate have continually occurred throughout geologic time. The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost and average of 281 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 119 billion tons during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade. 1. I already refuted this before. Each of the last three decades has been successively warmer at the Earth"s surface than any preceding decade since 1850 1. Already refuted this 2. After World War II, there was a huge surge in recorded CO2 emissions but global temperatures fell for four decades after 1940. "It is 'extremely likely that more than half of the observed increase in global average surface temperature' from 1951 to 2010 was caused by human activity. By 'extremely likely', it meant that there was between a 95% and 100% probability that more than half of modern warming was due to humans. - Intergovernmental Panel on Climate Change"s (IPCC) fifth assessment report. 1. There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man"s activity. 2. Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history. 3. Most of global warming is completely natural. 4. A large body of scientific research suggests that the sun is responsible for the greater share of climate change during the past hundred years. "Between 93% to 123% of observed 1951-2010 warming was due to human activities." - US Fourth National Climate Assessment 1. A large body of scientific research suggests that the sun is responsible for the greater share of climate change during the past hundred years. "Scientists Agree: Global Warming is Happening and Humans are the Primary Cause" - UCSUSA 1. The IPCC theory is driven by just 60 scientists and favorable reviewers not the 4,000 usually cited. 2. Leaked e-mails from British climate scientists - in a scandal known as "Climate-gate" - suggest that that has been manipulated to exaggerate global warming 3. A petition by scientists trying to tell the world that the political and media portrayal of global warming is false was put forward in the Heidelberg Appeal in 1992. Today, more than 4,000 signatories, including 72 Nobel Prize winners, from 106 countries have signed it. 4. A large body of scientific research suggests that the sun is responsible for the greater share of climate change during the past hundred years. Human influence on the climate system is clear, and recent anthropogenic emissions of green-house gases are the highest in history. ["] Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia." - IPCC AR5 1. There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man"s activity. 2. Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history. 3. After World War II, there was a huge surge in recorded CO2 emissions but global temperatures fell for four decades after 1940. 4. Warmer periods of the Earth"s history came around 800 years before rises in CO2 levels. 5. Despite activist concerns over CO2 levels, CO2 is a minor greenhouse gas, unlike water vapor which is tied to climate concerns, and which we can"t even pretend to control Of all the radiative forcings analysed, only increases in greenhouse gas emissions produce the magnitude of warming experienced over the past 150 years." - Berkeley Earth 1. There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man"s activity. 2. After World War II, there was a huge surge in recorded CO2 emissions but global temperatures fell for four decades after 1940. 3. Despite activist concerns over CO2 levels, CO2 is a minor greenhouse gas, unlike water vapour which is tied to climate concerns, and which we can"t even pretend to control Today, CO2 levels are 40 percent higher than they were before the Industrial Revolution began; they have risen from 280 parts per million in the 18th century to over 400 ppm in 2015 and are on track to reach 410 ppm this spring. In addition, there is much more methane (a greenhouse gas 84 times more potent than CO2 in the short term) in the atmosphere than at any time in the past 800,000 years"two and a half times as much as before the Industrial Revolution. While some methane is emitted naturally from wetlands, sediments, volcanoes and wildfires, the majority of methane emissions come from oil and gas production, livestock farming and landfills." - Earth Institute, Columbia University 1. There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man"s activity. 2. Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history. 3. Warmer periods of the Earth"s history came around 800 years before rises in CO2 levels. 4. After World War II, there was a huge surge in recorded CO2 emissions but global temperatures fell for four decades after 1940. Today, almost 100 percent [plus or minus 20 percent] of the unusual warmth that we"ve experienced in the last decade is due to greenhouse gas emissions," - Peter de Menocal, dean of science at Columbia University and founding director of Columbia"s Center for Climate and Life 1. There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man"s activity. 2. Despite activist concerns over CO2 levels, CO2 is a minor greenhouse gas, unlike water vapor which is tied to climate concerns, and which we can"t even pretend to control If the sun were brighter, we would see warming all the way up through the atmosphere from the surface to the stratosphere to the mesosphere. We don"t see this. We see instead warming at the surface, cooling in the stratosphere, cooling in the mesosphere. And that"s a signature of greenhouse gas forcing, it"s not a signature of solar forcing. So we know it"s not solar." - Gavin Schmidt, director of National Aeronautics and Space Administration"s Goddard Institute for Space Studies 1. A large body of scientific research suggests that the sun is responsible for the greater share of climate change during the past hundred years. Rest in comments section.

Correlation and CausationConsider the Cenozoic era (the last 65 million years). Overall, solar activity increased 0.4% over this period. "Because Earth absorbs about 240 W/m^2 of solar energy, that brightness increase is a forcing of about 1 W/m^2. This small linear increase of forcing, by itself, would have caused a modest global warming through the Cenozoic Era. " The CO2 levels caused a much higher forcing. In contrast, atmospheric CO2 during the Cenozoic changed from at least 1000 ppm in the early Cenozoic to as small as 170 ppm during recent ice ages. The resulting climate forcing, as can be computed accurately for this CO2 range using formulae in Table 1 of Hansen et al. (2000), exceeds 10 W/m^2. It is clear that CO2 was the dominant climate forcing in the Cenozoic. "[1]In fact, the temperature changes correspond to the CO2 changes. ". .. there is a close correlation between Antarctic temperature and atmospheric concentrations of CO2 (Barnola et al. 1987). The extension of the Vostok CO2 record shows that the main trends of CO2 are similar for each glacial cycle. Major transitions from the lowest to the highest values are associated with glacial-interglacial transitions. During these transitions, the atmospheric concentrations of CO2 rises from 180 to 280-300 ppmv (Petit et al. 1999). The extension of the Vostok CO2 record shows the present-day levels of CO2 are unprecedented during the past 420 kyr. "[2]This graph shows the CO2-temperature correlation over the last 700,000 years: Excess CO2 traps heat. Considering the recent global warming, satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat, thus finding ". .. direct experimental evidence for a significant increase in the Earth's greenhouse effect. " In other words, the Earth is retaining more of the heat that it receives from the sun that it received from before. This excess heat manifests itself through global temperature increases. "If less heat is escaping to space, where is it going? Back to the Earth's surface. Surface measurements confirm this, observing more downward infrared radiation. A closer look at the downward radiation finds moreheat returning at CO2 wavelengths,leadin to the conclusion that '. .. this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming. '"[3][4][5]Evidence of Mankind's Influence on the Recent Global Warming TrendIt would be rather coincidental if the recent rise in global warming happened to start just around the time that humans started to emit large quantities of greenhouse gases. However, there is direct evidence as well, in addition to the already established correlation between temperature and CO2. Now, it is known that CO2 levels are increasing. "In pre-industrial times over the last 10,000 years, CO2 was relatively stable at around 275 to 285 parts per million. Over the last 250 years, atmospheric CO2 levels have increased by about 100 parts per million. " CO2 levels are increasing at a level not seen in at least 500,000 years, if not longer. [6]Here is a graph showing CO2 concentrations over the last 10000 years: [7][8]Now, carbon has several isotopes, three of which are C12, C13, and C14. C14 is radioactive, and has a half life of around 5,730 years. The CO2 emissions that humans make come from fossil fuels. Thus, if humans were the cause of the excess CO2, we'd except the C14/C12 ratio to decline, because, while there is a relatively constant amount of C14 in the atmosphere due to continuous replenishment (when a neutron collides with a regular nitrogen atom, a C14 atom and a proton result), the amount of C14 in the Earth has steadily decreased because it is not replenished, and since fossil fuels come from the ground, almost pure C12 is being ejected into the atmosphere. Indeed, it is observed that the C14/C12 ratio has declined. And thus, if humans were the cause of the excess CO2, we'd except the C13/C12 ratio to decline, because plants find it easier to take in carbon dioxide with a C12 atom than one with a C13 atom, implying that plants have a lower C13/C12 ratio than the atmopshere and, since animals eat plants (either by directly eating then or eating something that eats plants), also implying that fossils also have a lower C13/C12 ratio than the atmopshere, implying that we'd see a decline in the C13/C12 ratio as well. Indeed it is also observed that the C13/C12 ratio has declined. [9][10][11]This can be observed in the graph below (this is the C13/C12 ratio over the last 650 years; the C14/C12 ratio graph was too big to put in the debate): The evidence that this excess CO2 is the cause of the recent global warming is voluminous. One piece of evidence is a comparison of warming in the troposphere and stratosphere. Because the CO2 is in the upper troposphere, the troposphere temperature would increase, while the stratospheric temperature would decrease, because there would be less heat reaching the stratosphere. "Computer model estimates of the ‘human influence’ fingerprint are broadly similar to the observed pattern. In sharp contrast, model simulations of internal and total natural variability cannot produce the same sustained, large-scale warming of the troposphere and cooling of the stratosphere. "[4][12][13]This graph shows this: [4]Another piece of evidence is the frequency of cold days and nights. Because the sun only shines in the day time, is the sun was causing global warming, the days would warm faster than the nights, while if greenhouse gases were causing global warming, this wouldn't be observed. It is the latter's prediction that is observed. "What we observe is a decrease in cold nights greater than the decrease in cold days, and an increase in warm nights greater than the increase in warm days. "[4][14]This can be shown in the below graph: [4]Overall, the evidence shows that human-emitted greenhouse gases are the cause of global warming. CO2, in addition to other gases like methane and nitrous oxide are being emitted by humans in very large amounts, and this is manifesting itself in an increase in the average global temperature. Climate Sensitivity and FeedbacksClimate sensitivity is the amount the temperature would rise if the CO2 concentration were doubled. Obviously, if there's a large climate sensitivity, then increases in CO2 have large effect. It is known that the climate sensitivity is around 1 degree C. However, this can be amplified through feedbacks. Positive ones amplify the sensitivity, while negative ones diminish the sensitivity. The evidence overwhelmingly comes down on the former, that positive feedbacks are happening. Increases in CO2 cause temperature increases, which are amplified by water vapor and the effect on clouds. "Since the radiative effects associated with the buildup of water vapor to near-saturation levels and the subsequent condensation into clouds are far stronger than the equilibrium level of radiative forcing by the non-condensing GHGs, this results in large local fluctuations in temperature about the global equilibrium value. "[15]This can be shown in the below graph: Further, increases in CO2 affect the carbon cycle in this way: Global warming can result in the death of vegetation (due to droughts) and the warming of the ocean. Both of these further reduce the maximum absorption of the Earths carbon cycle, thus resulting in even more CO2 being released into the atmosphere. And with this, CO2 increases even more. In other words, CO2-caused temperature increases are amplified by positive feedbacks and the mechanics of the carbon cycle. So, the positive feedback amplifies the climate sensitivity. How much it is amplified can be determined through study. Using a Bayesian statistical approach, which is “the dominant [method] in the literature”, these findings support the notion of climate sensitivity as maximum 4 degrees C, a mean of 3 degrees C, and likely not lower than 3 degrees. [16]The graph below gives a statistical analysis: [17]The mean is around 3 degrees C. The CO2 that humans emit thus has an effect of 3 degrees C per doubling of CO2. This can be shown by the fact that CO2 concentrations have increased from around 275 ppm to around 400 ppm. This is an increase of around 40%. This should manifest itself with a temperature increase of a little less than 1.5 degrees C. Indeed, temperatures have increased around this amount over the last 150 years. The anthropogenic-forcing climate models thus match observations. [18]In other words, in addition to the direct evidence of how the Earth is warming, the climate models based on a greenhouse gas cause to global warming explain almost perfectly the recent global warming. This is a lot of evidence for a human case to the recent global warming. ConclusionGreenhouse gases cause global warming because of their heat trapping abilities. Humans have been emitting vast amounts of greenhouse gases over the last 150 years, and this shows itself on the CO2 measurements. The atmospheric warming pattern and greater heating at night are evidence that the recent global warming is caused by those human emitted greenhouse gases. These increases are amplified through the water vapor and cloud positive feedbacks and the positive feedback that arises through the climate cycle. The climate sensitivity ends up being around 3 degrees C. Finally, the CO2-temperature record shows that the two correlate with remarkable correlation. SourcesSources in comments.