[Zuider]

Hans von Storch, professor at the Meteorological Institute of the University of Hamburg discussed this issue in a recent interview with Der Spiegel. He remarked that less than 2% of model runs reproduced the 'pause'.

http://www.spiegel.de/international/world/interview-hans-von...

SPIEGEL: Just since the turn of the millennium, humanity has emitted another 400 billion metric tons of CO2 into the atmosphere, yet temperatures haven't risen in nearly 15 years. What can explain this?

Storch: So far, no one has been able to provide a compelling answer to why climate change seems to be taking a break. We're facing a puzzle. Recent CO2 emissions have actually risen even more steeply than we feared. As a result, according to most climate models, we should have seen temperatures rise by around 0.25 degrees Celsius (0.45 degrees Fahrenheit) over the past 10 years. That hasn't happened. In fact, the increase over the last 15 years was just 0.06 degrees Celsius (0.11 degrees Fahrenheit) -- a value very close to zero. This is a serious scientific problem that the Intergovernmental Panel on Climate Change (IPCC) will have to confront when it presents its next Assessment Report late next year.

SPIEGEL: Do the computer models with which physicists simulate the future climate ever show the sort of long standstill in temperature change that we're observing right now?

Storch: Yes, but only extremely rarely. At my institute, we analyzed how often such a 15-year stagnation in global warming occurred in the simulations. The answer was: in under 2 percent of all the times we ran the simulation. In other words, over 98 percent of forecasts show CO2 emissions as high as we have had in recent years leading to more of a temperature increase.

[JoeAltmaier]

Confused: this is the hottest year on record worldwide. In what way is this 'taking a break'?

[tjradcliffe]

Simple: this is exactly what you would expect on a high plateau. Think about it in terms of climbing a mountain with a fairly flat top. For a long time you're moving continuously up-slope, then when you get to the plateau you wander around randomly and frequently find outcroppings that are higher than anything you've encountered before. That doesn't mean you're still climbing, and if we were still climbing at the rate seen from 1980-2000 the "global mean temperature" (which is a thermodynamically meaningless arithmetic average) would be even higher than what we see today.

People who continually beat on extrema (like Denialists who claim that cold weather on the East Coast last winter is somehow proof that AGW isn't happening) are adding noise to the argument, not signal. The physically meaningful number is the heat content of the Earth/ocean system, and there's quite a bit of evidence it is rising, and that a significant portion of that rise is due to human activity.

[DanBC]

And the ten hottest years have been since 1997?

[Tycho]

This makes me think of when financial journalists/broadcasters constantly report that the SPX or the DJIA or the FTSE or whatever are hitting 'all time highs' and it's a really useless piece of information. Investors want to know how much it went up by on the day (and what he trend of the last few days/months has been), the fact that it poked through to a new high level is not important.

[JoeAltmaier]

Except - temperature! It does actually matter if its 100 or 200 degrees.