Re: Marvin would love this news
quote: "on geological timescales, (your 80M years) you'd probably be in the right. Revert to mean n all that.
On our 200 year timescale any rapid increase is suspicious, innit? Certainly atmo CO2 increase has been pretty dramatic over that time and totally out of line with "millions of years"."
Regarding CO2, here are graphs for CO2 levels for the last ~400 million years alongside temperatures for the same period
You'll note that there are points where high CO2 correlates with high temp, and also points where low CO2 correlates with high temps. There are also points where increasing CO2 correlates with rising temps, and points where increasing CO2 correlates with falling temps. I'd especially draw your attention to the points between 250-100Mya; if you follow the 30Myr filter line, we sat around 1500-2000ppmv CO2 (4-5 times more than today), and overall it was indeed warmer than now. However over that period, the first 50My have increasing CO2 (1500ppmv to 2000ppmv) and falling temperatures, the second 50My have decreasing CO2 (2000ppmv to 1500ppmv) and falling temperatures, and the last 50My have increasing CO2 (1500ppmv to 2000ppmv) and rising temperatures.
Over the scale of those graphs, 200 years are insignificant, we can only talk about long term trends. Also, all of those data points are calculated, none were observed. So while I am in agreement that the data from the last 200 years is explicitly more accurate than any calculated paleoclimate data, paleoclimate data does not support the hypothesis that increased CO2 inevitably and immediately causes increases in global temperatures. An increase of 500ppmv (33% extra at the time) somehow failed to increase global temperatures over a 50 million year timescale (250-200Mya), it barely even slowed an existing decline. Claiming it can (and will) dramatically increase global temperatures in less than a century does not fit those existing data sets, and to be scientifically sound, any new theory has to both fit existing data as well as accurately predict new data. Something is not right, and I would be far more suspicious of people deciding to rewrite paleoclimate data to fit the current models, than of people rewriting the current models to fit paleoclimate data.
Anyway, moving on from my rant regarding some less than scientific practise amongst people calling themselves scientists, I think we mostly agree that people should be doing proper science (which by definition includes unbiased research), and also properly planning for the impact of increased global temperatures. Regardless of who's (or what's) fault it is, we're going to have to live in a warmer world, so we'd better make sure we can do so, right?