Not sure where you seeing warming starting in 1700. To my eye I don't see a change in trend until 1900. Perhaps you are looking at the pink line and that other one? I discount those as they are outliers. I don't see any definitive change until around 1900. But I suppose it depends on how you look at it. Perhaps this shows it better.
this study cited by fraudcurrents... has been pretty much shot down... but recent studies and observations of water vapor and clouds... since this study... there have been new studies that show water vapor and clouds probably have a net cooling effect... especially in the tropics. and more that once... I have shown fraudcurrents NASA's website where they admit they don't understand co2 impact on clouds or even the impact of clouds themselves on temperature. in addition to what lucrum stated the point is this level of warming was natural in the past. And we really don't know what the real level of co2 was... as we were not there to measure it.
True. I'm more interested in crops and crop yields than temperature representations. And I don't want to get jem started. (oops, too late)
I largely agree with you, but disagree on what I consider important points. I am in agreement that it matters what the cause is for the increase seen from he late 19th Century up until approximately 1997. The problem is that a few tenths of a degree increase is so small compared to natural variation that we are at a loss to distinguish it. Being able to distinguish it is not critically important however. What is, is whether Hansens hypothesis is correct, because if it is, we could be in serious trouble! But we can't escape the reality that there has been no net detectable increase since about 1997 (or so), and that considerably weakens the probability of Hansen having been correct. So we are talking now about the increase between the late 19th Century and about 1997. It would be nice to know what caused that, but it is far more important to know whether Hansen's hypothesis is correct. A place where we would disagree is what the preponderance of evidence is telling us and of the importance of public opinion. The preponderance of the evidence is telling us that the Hansen's hypothesis is wrong, and it is telling us unequivocally so. Consequently we do not have to be concerned about reaching a Hansen "tipping point" due to positive feedback beyond which we would see a rapid uncontrolled increase in temperature. We should not decide scientific questions by opinion polls nor media hype. We should let all that stuff, including marches and banner waving, go in one ear and out the other. We should, on the other hand, pay close attention to what the majority of meteorologists and atmospheric physicists are saying, and they are now saying what Lindzen is saying (the majority, not all). They are saying we can't tell the slight increase in temperature we experienced over the past 150 years from the natural variance of climate. It is, however, consistent with the measurable rise in CO2 plus the other non-condensing greenhouse gases. And although we as yet don't have a way to distinguish what fraction of the increase in CO2 is man caused, because CO2 exchanges far more rapidly than Hansen originally thought, and the natural sourcing and sinking is two orders greater than man's emissions. (Many have just assumed that the increase is mostly due to man because the increase very roughly approximates the amount we have emitted.) The early hope that man's fossil fuel emissions had a unique isotope signature have been dashed upon the rocks by discovery that even larger natural emissions have the same signature. Most importantly, for the purpose of addressing the validity of Hansen's hypothesis, is any evidence of positive feedback. (See Lindzen's talk before the House of Commons for much detail on this matter.) We now have -- in Hansens's defense, we didn't in 1988 -- unequivocal evidence that there is feedback, but it is slightly negative, not positive as required by Hansen. That is to say that the response of our biosphere to a temperature rise is to dampen it via negative feedback, rather then amplify it via positive feedback. This is consistent with the known history of the atmosphere. It's also logically gratifying, because if the feedback were positive none of us should be here! (This is something Hansen, unaccountably, missed in putting forth his hypothesis.) The satellite data, which is the best and most reliable data we have, shows us the feedback is negative, not positive.. Those are facts. We should accept them. If we don't, we will surely look like fools to future generations. What should we do then. Well, we should still be conscious of our CO2 emissions and, for several good reasons, try to convert, at a reasonable pace, to alternate forms of energy with a smaller carbon footprint. And we should be good protectors of our biosphere. We need to protect our oceans and our forests from pollution and destruction. The animal kingdom's success is integrally linked with that of the plant kingdom. We must avoid over population. Birth control is hugely important if we want to be kind to our environment! I would say that if one feels the urge to take up a banner and march, then by all means march for birth control. We should avoid, however, making public policy based on an incorrect hypothesis. To do so is nonsense. Thank you, by the way for not calling every one you disagree with, including those scientists you've never met who have long-standing international reputations in atmospheric physics, "idiots and frauds". How very refreshing it is to have a discussion without name calling.
And you claim that the amount of CO2 released into the atmosphere over the last hundred years is no different that at any other time during the last millenium?