Select to expand quote
holy guacamole said..
You're obsessed with Cook aren't you? I'll let you stew over Cook ......
Not particularly, I am merely providing references that you will be comfortable with. If I quoted a source you viewed as flawed becuase it was from a "denier" with some other agenda you will just dissmiss it irrespective of it's accuracy. So I use Cooks mob at Skeptical Science a lot.
Select to expand quote
holy guacamole said..
The underlying trend you refer to was very weak until 1950 when GHG's started to spike. I don't expect you to accept the solidity of that observation and logical inference.
Lets look at the graph again. I agree there is a strong warming trend since about 1970. Yes there is correlation with that trend and significant increasing CO2 from about 1940 and we know that CO2 has the possibilty to warm the atmosphere. However there was also an almost equally strong increasing trend from 1910 to 1940 (very small amount of additional CO2 at that time), which continued an ongoing longer term trend from around 1810. This is a short amount of data in the scheme of things, but the reality is that no one can say what the trend might have been with no additional CO2, but more importantly you cannot dissmiss the posibility that much of this trend is and extention of a warming movement that started naturally 200 years ago.

A simple regression line on the data would suggest that the natural warming pattern prior to 1970 would account for all but 0.5deg of observed warming to date. It's crude and highly error prone but it does match roughly with the 1 deg of warming per doubling of CO2 a lot of scientists suggest is the maximum we can expect.
The graph also highlights that the rate of warming we are seeing is strong, but it's not unprecedented even in the last 200years. One could also argue the 95% uncertainty areas indicate we are not even 100% sure that it wasn't this warm in the late 1700's.
No one is saying CO2 isn't contributing, but because we don't know its magnitude, we must also consider a large portion of the trend could be natural. The point is there is an equally plausible hypothesis that competes with the CO2 influence hypothesis, and there is no evidence to definately say one or the other is dominant and that is why there is debate and uncertainty. We dont know.
Select to expand quote
holy guacamole said..
You're still yet to provide any evidence that supports your theory that there is quote "hot debate" about the anthropogenic contribution to warming observations since the middle of last century. I don't expect much to materialise from you in this regard because this so called "debate" tends to come from fossil fuel stooges and spin doctors. People with links to fossil fuels, dodgy think tanks and propaganda organisations.
Once again, ive posted a link to Skeptical Science that admits there is debate and uncertainty over the magnitude of the influence of CO2. If they admit it then you would have to be inclinded to beleive them as it works against thier cause. As CO2 is hailed as the biggest contributer to AGW then by association AGW contribution is debated.