global warming is significantly man man made

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.