Arctic Methane - This Does Not Sound Good...

[Nederland]

86. It would be helpful...

...if you actually took the time to read and look at what I post. I've never used short year slump data anywhere.

Let's review.

Look at the graphic I posted in #71. The point of that graphic is that regardless of what trend you believe is the "correct" one, they are ALL well below a rate that would put us at 5 or 6 degrees by 2100. Even if you cherry pick the highest trend--the 20 year trend--you end up with something slightly under 0.2 degrees per decade. Given that IPCC models show a fairly flat rise in temperature over the next 100 years, that suggests that we are not anywhere close to the 0.5 or 0.6 degree rise per decade trend you would need to get to 5 or 6 degrees total by 2100.

Now look at the graphics in post $#71. That is not "short year slump" data either--it shows 12 and 22 years of data respectively. Those graphs show that ALL of the land based temperature records have slopes under 0.2 degrees per decade, and that actual temperature numbers have been coming in UNDER model predictions for as long as they have been predicting (keep in mind that the models displayed are AR4 models whose runs were done in 2006--anything before that is hindcasting and doesn't count). Most significantly, the line has just dropped below the one sigma line, which is where you need to be to claim 68.3% likelihood. When people like Al Gore said "the science is settled", I'm pretty sure most people thought he was talking about something probabilities higher than 68%.

Now, is it possible that the temperature line will rise back up above the sigma one line? Absolutely. In fact, it is downright likely. However, every year that passes makes it harder and harder to get back where you really need to be--between the sigma two lines--the typical scientific standard for saying something has been "proven correct". Just look at the graph and where we are today. At this point you will need several years of temperature increases beyond those we saw in the blistering 1990's just to get back into a trend that yields the mean IPCC predicted 2.5 degree rise by 2100. To push the numbers high enough to get to a trend that yields a 5 or 6 degree rise by 2100 you would have to have consistent increases that we have never seen before for ten years or more in a row.

Could that happen? Of course. But until it actually does happen I'm going to repeat what I said earlier: current temperature trends simply do not support that notion that we are in for a 5 or 6 degree rise by 2100.