Global warming is likely (and mostly) anthropogenic

1. Correlation CON essentially says a robust correlation does not increase the chance for causation, only the relationship. However, for this correlation to be robust is has to precede the warming (or, in others, amplify them). In this debate I have not said CO2 is the only factor in climate change, rather it is the largest factor in modern climate change. In past cycles, CO2 has often played a secondary role, however amplifying warming significantly—and in other cycles it may have even been a predominant factor. My opponent ignores the study by Shakun, which found that CO2 preceded the warming at the end of the ice age. So, assuming CO2 still plays a secondary role, all Co2 needs to do is precede modern warming to show causation. Because if it is an amplifier, if it precedes now it likely plays a significant role. So, since CO2 has preceded modern temperature (and some older temperatures) [1]. My opponent’s second claim is from a source that denies the greenhouse effect—even Anthony Watts has responded to their literature and claims that they are misrepresenting science. The Press release by my opponent’s source assumes the atmosphere (upper and lower) work the same. Of course the upper atmosphere cools the planet by reflecting the sun’s rays, if it didn’t we would be dead [2]. The upper atmosphere cooling actually proves man-made climate change. The upper atmosphere has cooled, as shown by satellites, and this has been predicted by models—and the cooling is because of the lower atmosphere greenhouse effect [3]. We can also determine the power of CO2 from outgoing radiation measurements. A 2004 study has found that outgoing radiation has been decreasing due to the greenhouse effect [4]. These studies have been cited throughout the debate. Skeptic Roy Spencer has even supported the CO2 greenhouse effect [5], though he thinks the effect is minimized via feedbacks (discussed R2). 2. Correlation strength My opponents graphs rely upon data from Joseph D’Aleo. His study is also flawed in that it included data from pre-1970s. The IPCC and others have argued Co2 played a large role, but not a near-100% role, in that time period. It merely dilutes CO2’s near-100% role after that date. Further, it includes the cooling between 1950-60. This period still had a strong CO2 effect… why did it cool? Aerosols cooled the climate and temporarily override the greenhouse effect of the CO2 increase [6]. Even if we add the beginning part, the middle cooling is responsible for the low correlation. This would be easily fixed if the cooling was accounted for by aerosols. And, if we add that in, it warms in that period. The PDO, too, has seen little change and has cooled since the 1980s [15] I find a bigger problem: the study used local US data versus global CO2 data. The fact he didn’t use global data for both obfuscates the results and renders them useless. A study by Amman et al. 2003 finds when we compare the Keeling curve to GLOBAL temperature, we get an excellent correlation [7]. 3. Ocean levels To say that Co2 levels are not unprecedented is absolutely false. My opponent cites data from millions years ago. If temperature is causing the increase in CO2, and not vice versa, to obtain the CO2 level of 100 million years ago would have to mean unprecedented warming. This is in direct contradiction to my opponent’s later argument. If he says that we are 100 ppm above 2 million years ago, it means we have to be at the same temperature to meet that CO2 level (it was hotter then) if we say it is all natural. This forces him into contradiction. Human CO2 is identifiable to natural CO2. Studies have shown most of this CO2 is from fossil fuels [8]. To say humans are only a tiny fraction of the atmosphere is false. “Before the industrial revolution, the CO2 content in the air remained quite steady for thousands of years. Natural CO2 is not static, however. It is generated by natural processes, and absorbed by others. … But consider what happens when more CO2 is released from outside of the natural carbon cycle – by burning fossil fuels. Although our output of 29 gigatons of CO2 is tiny compared to the 750 gigatons moving through the carbon cycle each year, it adds up because the land and ocean cannot absorb all of the extra CO2. About 40% of this additional CO2 is absorbed. The rest remains in the atmosphere, and as a consequence, atmospheric CO2 is at its highest level in 15 to 20 million years”.[9] My opponent misrepresents his source on CO2 lag. It says “until now the most comprehensive records to date on a major change in Earth’s climate came from the EPICA Dome C ice core on the Antarctic Plateau”. In other words, the data my opponent cited is old school. The newer studies drastically reduce the lag to less 200 years and use less flawed ice core data [10]. The reduced lag actually shows that CO2 could have been a driver in past climate [11]. 4. Past Climate I did present evidence—the fact I cited the whole paragraph I thought was noticeable. Although regionally the MWP was warmer, specifically in the Atlantic, global temperatures refute this conclusion and find that the MWP was cooler than today [12]. A study by Kellerhals et al. finds that South American temperatures rose, but not to the levels of modern day warming [13]. The MWP can be found in regions like my opponent pointed out, but the data shows that global temperatures were cooler in the MWP [12]. 5. The sun Closer examination of cons study yields this result, “Although the inferred increase of solar irradiance in 24 years, about 0.1 percent, is not enough to cause notable climate change, the trend would be important if maintained for a century or more”[14]. It will be important in the future, but has not been important as of recently. The study my opponent cited refutes his sun-climate link for the 20th and 21st century. CONCLUSION His case, although he claims refutes mine, has been torn down with the facts. My opponent has been unable to de-link CO2 with past climate and modern climate, show natural cause, and his outright opposition to the greenhouse effect is unscientific. Even skeptic scientists agree that CO2 has some warming potential. 1. http://tinyurl.com...; 2. http://tinyurl.com...; 3. http://tinyurl.com...; 4. http://tinyurl.com...; 5. http://tinyurl.com...; 6. http://tinyurl.com... 7. http://tinyurl.com...; 8. http://tinyurl.com...; 9. http://tinyurl.com...; 10. http://tinyurl.com...; 11. http://tinyurl.com...; 12. http://tinyurl.com...; 13. http://tinyurl.com... 14. http://tinyurl.com...; 15. http://tinyurl.com...