Does the data support anthropogenic global warming theory?

[Eric_meyers]

According to HadCRU global temperature warming per decade has been .12C with uncertainty intervals of .13C (since 1995) (using Santer17 formula) which given my thoughts of an upward heating bias due to data handling and urban heat island effect still indicates that since 1995 - there has been no statistically significant warming.

Other data metrics, such as UAH and RSS show cooling trends from 2001-2008 which invalidate the IPCC's 2C/century claim within 95% confidence intervals http://rankexploits.com/musings/2008/ipcc-central-tendency-of-2ccentury-still-rejected/

Obviously this cooling trend is too short a time period to adequately correct for possible noise, but I do believe that since the PDO shifted to "cool" this year temperatures will decline immensely, recently a strong negative SOI came up almost erupting into a new La Nina, I do say if global warming is suppose to be occurring from all this build up of CO2 and other related GHG's, it sure is well hidden.

 

[Gokul43201]

The AMO is also near a peak and will likely begin a downswing soon. So, yes, there may very well be a weak cooling trend over the next couple of decades. But does that refute the possibility of an underlying warming trend from CO2? No.

Come back to this thread in about 20 years and we can compare the cooling trend (if there is one) over the 2010-2030 period with the trends during past downswings of the AMO and PDO (say, with the 1955-75 and 1885-1905 periods). We can do all kinds of happy analysis, weighting for the amplitudes of the oscillations and factoring in solar cycles, sunspot activity, magnetosphere variations, correcting for ENSOs, geological activity, land use, piracy in the high seas and everything else you can think of. Then if there is no residual trend of warming, it's not very good news for the AGW models. If there is, then they get to gloat, justifiably or not.

Over the next 20 years though, I expect the state of the science to have evolved at least a little bit.

Right now, to paraphrase your own words - there's not enough data to ask a meaningful question about whether the data supports anything (especially if you are going to choose endpoints - like 1995 - that are not designed to minimize errors from noise).

 

[Haelfix]

My personal take after going over the science is that yes, indeed there is evidence and strong correlation in the data sets with the anthropogenic hypothesis.

What I feel is controversial is exactly how much this effect is or is not important (judged by numbers like the climate sensitivity) and crucially what sort of confidence and statistics are used in ascertaining whatever number comes out. Frankly, there's some rather sloppy math in the literature (particularly by the IPCC groups) with regards to the latter question and I am skeptical if anyone really can make both a precise and accurate mathematical statement about it without using a simplified toy model.

 

[vanesch]

My personal take after going over the science is that yes, indeed there is evidence and strong correlation in the data sets with the anthropogenic hypothesis.

What I feel is controversial is exactly how much this effect is or is not important (judged by numbers like the climate sensitivity) and crucially what sort of confidence and statistics are used in ascertaining whatever number comes out. Frankly, there's some rather sloppy math in the literature (particularly by the IPCC groups) with regards to the latter question and I am skeptical if anyone really can make both a precise and accurate mathematical statement about it without using a simplified toy model.

my uneducated guess also.

 

[Andre]

My personal take after going over the science is that yes, indeed there is evidence and strong correlation in the data sets with the anthropogenic hypothesis.

What I feel is controversial is exactly how much this effect is or is not important (judged by numbers like the climate sensitivity) and crucially what sort of confidence and statistics are used in ascertaining whatever number comes out. Frankly, there's some rather sloppy math in the literature (particularly by the IPCC groups) with regards to the latter question and I am skeptical if anyone really can make both a precise and accurate mathematical statement about it without using a simplified toy model.

Could you share those data sets, so that we can judge the science as well?

No need for links, just references,