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Real climate has disproved all models to date. There has been no forthcoming explanation for the 15 year hiatus in warming. In other words the science underlying climate is far from known. As Feynman reminds us “It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.”. Thus we have to push on and cannot advise politicians.

Since 1979 the IPCC report has published a best estimate for the climate sensitivity. Its latest report says "No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines of evidence and studies.".

It is not a question of denying or conspiring. It's a matter of discovering the science behind our climate. Let's do it without the silly rhetoric.

By the way, if you believe the very worst prediction (proposed on the basis of failed models) then you will be interested in this link which asks what the cost of 'doing something' is. http://topher.com.au/50-to-1-video-project/

2 comments

You're proposing "discovering the science behind our climate" by ignoring what the actual scientists are saying. For example their explanation for the 15 year pause http://www.theguardian.com/environment/damian-carrington-blo...

You'll note that the article carefully doesn't link to actual data showing the amount of heat that has actually been "trapped". (No, the IPCC report is not "data". I'm talking about actual data sets that are archived on publicly available servers with cryptographic signatures to ensure that it's complete and intact. You know, the sort of thing that is routine when you're downloading a piece of code, but which the climate science community has decided is much too difficult for data on which they want to hang the fate of the planet.)

Reading between the lines, their numbers for "trapped heat" are based on computer models, not on actual data; what they're basically saying is "the only data we have doesn't show the heat, but our models say it should be there, so we assume it went into the oceans".

Good demonstration of my point. You refuse to believe what actual scientists are saying.

I refuse to believe it without checking it, yes. (I noted somewhere upthread that there was a link to a GRL paper that might shed more light on the details in this particular case.) I take the same attitude when I read a claim about physics. I don't accept arguments from authority, and that's what "actual scientists are saying it" is. Actual scientists can be wrong. So can I, but that doesn't mean they get a free pass.

What are you talking about?

http://blogs-images.forbes.com/petergleick/files/2012/02/Glo...

That's because they carefully picked 1997 as the starting year. What does the trendline look like if you pick other starting years?

More generally, why do we assume that a linear trendline is the appropriate way to analyze this data? Has anyone actually done an analysis that doesn't start from that assumption?

Here's from 1880, with a non-linear trendline: http://blogs-images.forbes.com/petergleick/files/2012/02/Glo...

The full article is here: http://www.forbes.com/sites/petergleick/2012/02/05/global-wa...

Thanks for the links. I at least see why the second graph had to pick 1880 as the starting point, since that's as far back as the instrumental record it used went. And at least it considered the possibility of a non-linear fit.

However, the curve fitting is still subject to error, because you don't have the trend before 1880, at least not in this dataset. What if the temps around 1880 were anomalously warm compared to, say, 1800? (Which we have reason to believe they were.) Then the actual trendline from 1800 or so might still be roughly linear.

But more importantly, 1880 is still an arbitrary starting point; any starting point is arbitrary unless you know you have the entire dataset, which we obviously don't. If the actual trend is, say, a sine wave with a period of roughly 800 to 1000 years, with the last peak being around 1000 - 1200 AD and the last trough being around 1600 - 1700 AD, what we're seeing now could just be the approach to the next peak.

I note that the article links to a GRL paper, which I'll have to read; its abstract doesn't make it quite clear what is actual data and what is extrapolated from models.

For funsies, I fitted linear trend lines to a sliding 15 year block, and plotted the slope of the trend line.

http://imgur.com/CYc5G5A

Top graph is slope of a linear trend line for the 15 years prior to each indicated year. Bottom graph is the underlying temperature data.

For 30 of the 15-year blocks the trend was negative; for 88 the trend was positive. The last year in which there was a linear cooling trend for the 15 years prior was 1977.