Global warming is likely (and mostly) anthropogenic

Correlation Deception First off I did not ignore Pro’s study I rebutted it with a more recent study, which was much more extensive than the study provided by Pro. This false accusation is a weak attempt to deceive the voters. Furthermore, while Pro has not claimed CO2 was the only cause of global warming, he did argue than man was the main cause of global warming due to their production of CO2. Lag Pro tries to claim that temperatures now lag behind CO2. In actuality CO2 still lags behind temperatures. The only difference is that instead of lagging by hundreds of years it now lags by only 11 to 12 months. (1) Greenhouse Effect I have not now, nor have I ever denied the existence of the greenhouse effect. I do however disagree to the extent in which man has contributed to the greenhouse effect. As Pro’s chart shows, the greenhouse effect converts solar activity to heat in the lower atmosphere, but in the upper atmosphere it prevents solar activity from reaching the lower atmosphere. If the cooling effect in the upper atmosphere is 100 times greater than the heating effect in the lower atmosphere, than the cooling effect of the upper atmosphere cancels out the heating effect of the lower atmosphere. You cannot look at one without the other. Correlation strength Pro’s rebuttal is based on the assumption that temperature now lags CO2; which it clearly does not. The role CO2 plays in global temperatures, if any, is too insignificant to be of any concern. (1) According to geological records, sunspot cycle length plays a much larger role than CO2. It is far more likely that the sun is the real cause of Global Warming. (2) My opponent cited a graph with a J-peg link, so I have no info to verify his study. Pro claims that the graph shows a stronger correlation using global temperatures, yet fails to provide any statistical information regarding the claim. By looking at the graph, I cannot see a strong correlation, as many times the temperature dips as CO2 rises, and the data points in the trends don’t seem to correlate with one another. A bigger issue is that looking at past data, the correlation between CO2 and global temperatures tends to be very week. When CO2 was 7000 ppm the global temp was only 22 ºC, which was the same global temperature as when it was 1200 ppm. (3) Ocean levels Pro claims that if CO2 levels were the same as millions of years ago, than there would be unprecedented warming; this is a false assumption. I did not say that temperature always correlates with CO2; only that recent correlation can be explained by oceanic temperature fluctuations. There are a number of other causes for CO2 levels, throughout history. This only shows that CO2 levels were much higher in the past, and it was not the end of the world. That 2% figure came from the data pro provided. Pro tries to claim that a correlation between the industrial revolution and the rise in CO2 proves man caused the rise; once again correlation does not equal causation. According to studies, man is only responsible for 3.225% of CO2, which is close to the 2% figure received from Pro’s data. Water vapor also accounts for 95% of all greenhouse gases. (4) Pro misrepresented my source. My source said, “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.” Pro skipped to the end of the article, clearly without reading its contents. At the end of the article it says that “Parrenin’s team addresses these concerns with a new method that establishes the different ages of the gas and ice.... The researchers then compared results from multiple locations to reduce the margin of error.” Thus the raw data showed a gap of up to 1,400 years. After correcting for the margin of error their published results “show CO2 lagged temperature by less than 200 years”. The study still found that CO2 lagged temperature; by correcting for the margin of error they reduced the gap. (5) Past Climate Pro attempts to refute my source, by citing Wikipedia; wiki is not the most reliable of sources. Even if the medieval warming period was on average cooler than today, it does not negate from the fact that the earth was much warmer in earth’s history previous to the medieval warm period. The medieval warm period occurred before the little ice age, and we have been warming since the end of the little ice age. Simply because it is hotter in point B than in point C does not mean man caused it to be hotter, especially when point A was hotter than point B and point C. Most of the history of Earth’s temperature was remained unchallenged because pro decided to fixate on the medieval warming period. 5. The sun Pro is once again cherry picking quotes from my source, in order to misrepresent my sources. Pro tried to quote my NASA source, in attempt to prove that the increase in sun activity was insignificant. But he quoted them out of context. The current heating trend was caused by the sun, but for it to pose any real threat it would have to continue for a century or more. If pro read on he would have seen that my source also says; “TSI interaction with the Earth's atmosphere, oceans and landmasses is the biggest factor determining our climate. To put it into perspective, decreases in TSI of 0.2 percent occur during the weeklong passage of large sunspot groups across our side of the sun. These changes are relatively insignificant compared to the sun's total output of energy, yet equivalent to all the energy that mankind uses in a year. According to Willson, small variations, like the one found in this study, if sustained over many decades, could have significant climate effects.” (6) Conclusion CO2 has a week correlation to the changes in temperature. In recent years the correlation has gotten stronger, but the correlation lags behind the temperature fluctuations. The cooling effects of greenhouse gases are 100 times greater than their heating effects. Most greenhouse gases are natural, with only a tiny fraction being man made. The sun is primarily responsible for climate change. 1.) http://www.thegwpf.org... 2.) http://paulmacrae.com... 3.) http://www.ei.lehigh.edu... 4.) http://blog.deadlycomputer.com... 5.) http://www.scientificamerican.com... 6.) http://www.nasa.gov...