• CON

    However, Pro's figure shows is that the model predictions...

    Anthropogenic Climate Change Exists

    CO2 has increased by 54% in past 17 years with no global warming, and CO2 theory cannot explain why NASA data, which I cited in [6], shows there has been no global warming for 17 years. Here is the graph from [6]: Pro argued that the average temperature for each decade has increased for each of the last three decades. That does not contract the fact of there being no global warming for 17 years. Suppose the temperature anomalies were scaled to be 1 in 1980, 2 in 1990, 3 in 2000, and 3 in 2010. Then the decade averages would be 1.5, 2.5, and 3 respectively, with a higher decade average despite no increase in the 2000s. The post-2010 data, which Pro did not consider, also shows no temperature increase. Temperatures rose sharply in the 1990s, so the average for the decade is about half way between the low at the start of the decade and the high at the end. There is no increase from the end of the 90s to the present, so saying the average for 2001 through 2010 is higher than the 90s only says that 90s were warmer at the end of the decade than the beginning. My primary reference for the claim that that IPCC models cannot explain the 17 year lack of global warming is Tinsdale's book “Climate Models Fail” [7]. Tinsdale provides a book length comparison of IPCC model results showing that what actually happened in climate was outside of the error band of model predictions. Tinsdale correctly references Von Storch, but I provided the wrong link, for which I apologize. The Von Storch paper cited by Tinsdale is online, but it can only be accessed with academia.edu membership [17. http://www.academia.edu...] Storch says “we find that the continued stagnation in global warming, from 1998 to 2012, is inconsistent with model predictions, even at the 2% confidence level.” Tinsdale also referenced the Mauritsen paper, which I linked in [7]. Like Von Storch, it shows that no reasonable tweak in the IPCC models can bring then into agreement with what actually happened. If CO2 dominated climate in the 20th century, then temperature should have risen monotonically through the century. If fact, there was a sharp decline at the beginning of the century and long gradual decline from about the 40s through the 60s. The general trend is upwards, but a general upward trend is what we would expect if sunspots dominated climate. I presented the sunspot graph previously, but here is a nicer rendition [18. http://www.paulmacrae.com...] Temperature is closely following sunspot activity, but not CO2, through 2000 The continuation, below, shows the pause in global warming post-2000 is consistent with the sunspot cycle having peaked. [19. http://wattsupwiththat.com...] The 17 year pause in global warming is causing great consternation among scientists who previously believed CO2 predominated. A news report by Voosen summarizes the widespread recognition among scientists that the models are not working, and that some major factors are missing, although among CO2 advocates, there is no agreement among CO2 theorists as to what is wrong. [20. http://www.eenews.net...] Pro's [5] shows that natural forcing of climate is only a minor part of the model predictions. However, Pro's figure shows is that the model predictions are completely wrong. Temperature was supposed to rise sharply after 2000, as the figure shows, but it did not. Models proved wrong cannot be relied upon for future predictions. As Voosen documents, in the IPCC models, sunspots are only modeled as having a direct irradiance effect, and that effect is negligible for the 20th century through the present. Something else is happening that gives sunspots a much greater influence on climate. Total sea ice is at a high Pro's initial contention was that vanishing Arctic sea ice proves that CO2 dominates climate. That's wrong on two counts. Correlation does not prove causation. Also, global warming is global, so it cannot be that Arctic ice measures warming but Antarctic ice does not. In the last round, Pro changed his position and argued that total ice is important and not sea ice. But total ice has been decreasing since the early 1800s, well before any claim of anthropogenic warming. [21. http://www.davidarchibald.info...] Total ice shrinking doesn't say anything about the cause. Pro claimed that melting land ice in Antarctica caused the increase in sea ice. That's impossible, because 99.9% of Antarctica has never gotten warm enough for ice to melt. There is a tiny peninsula that goes far enough north to occasionally have some melting, but that's negligible. Future CO2 levels are unknown Pro speculates that once there is any warming from anthropogenic CO2 it will take 10,000 years or even millions of years to correct. Pro agrees that warming causes the release of CO2 from the oceans. That does not address the issue of what future CO2 levels will be. It only says that if there is warming from some cause, that the CO2 levels in the atmosphere would be higher, after some delay, than if CO2 were not released from the ocean. We know it is not the case that warming causes a runaway of temperature due to the release of CO2 causing further warming. The data by Rasmussen [15] shows that CO2 goes up and down following temperature with a lag of a few hundred years, and that is true when either temperatures or CO2 levels are higher than present. It cannot matter whether there was one degree of warming due to sunspots or due to anthropogenic CO2, if any warming were to cause a CO2 induced runaway of temperature, it would have shown up in the temperature and CO2 variation of the past 250,000 years, and it has not happened. All of the IPCC models assume that CO2 levels in the atmosphere are dominated by a continuing exponential rise in anthropogenic CO2. But fossils fuels are unquestionable being exhausted, so it is impossible for CO2 levels from burning fossil fuels to continue to rise exponentially. The only question is when anthropogenic CO2 will fall below the assumed exponential increase. Prof. David Archibald, an expert on fossil fuel reserves claims, “At best, we might get to about 600 ppm ...” [21. p.91] As fossil fuels become scarce the price will rise, which will lead to the use of alternatives like nuclear power, which is present only marginally more expensive than fossil fuels. But let's suppose that the 600 ppm level is reached at the end of the century. That's a 56% increase in CO2. But the 54% increase in CO2 in the past 17 years produced no net increase in global temperature. Because scientists agree CO2 warming is logarithmic, the same percentage increase should produce the same amount of warming. The CO2 warming of the past 17 years was canceled by natural phenomena not in the climate models, so Pro's claim that the climate problem is solved is false. Is 600 ppm total CO2 is the correct number? I don't, and no one knows for sure. The upper limits and the future rates of CO2 production are major unknowns that make it impossible for Pro to meet his burden of proof. Climate prediction based upon solar activity The IPCC model projections of climate depend upon the CO2 effect on warming being multiliplied by a positive factor of two or more by secondary effects, such as the warming increasing water vapor in the atmosphere. Archibald [21. p 1] summarizes: The real world evidence says the opposite. In late 2007, Dr. Roy Spencer of the University of Alabama published a paper analyzing data from the Aqua satellite. Based on the response of tropical clouds, Dr. Spencer demonstrated that the feedback is negative. He calculates a 0.5°C warming for a doubling of the pre-industrial carbon dioxide level. Global warming, as caused by carbon dioxide, is real but it is also minuscule, and will be lost in the noise of the climate system.

    • https://www.debate.org/debates/Anthropogenic-Climate-Change-Exists/1/