Global Warming Did Not Pause [Greg Laden's Blog]

You’ve heard much about the so-called “pause” or “hiatus” in global warming.

One of the implications of a multi-year “pause” in global warming is that the science of global warming must be somehow wrong, because with CO2 rising in atmosphere, due to human activity, how can the surface not warm? However, surface temperatures have been rising, but at a somewhat slower rate than at some other times.

The truth is that there is a lot of variation in that upward trending surface temperature value, measured as an anomaly above expected temperatures. Sometimes the variation pushes the rate of warming up, sometimes it pushes the rate of warming down. This has always happened, and will always happen.

So there was something of a lowering of rate of surface warming, but at the same time, no such reduction in rate of ocean warming. Most of the heat from global warming is added to the ocean, not the surface. So, the reality is, global warming has been continuing apace.

One of the factors involved in a slowdown is probably the fact that the Pacific Ocean has been absorbing more heat, for a longer period, relatively uninterrupted by large El Ninos (which reverse that trend), for longer than usual. This year’s El Nino is returning some of that heat to the atmosphere. But even before El Nino kicked in, we were having month after month of record breaking heat (with the very rare month not being a record breaker) for a long time.

Anyway, a couple of papers have recently been published that look once more at the “pause” and I wanted to point them out. The best way to get at these papers is to read the guest commentary by tephan Lewandowsky, James Risbey, and Naomi Oreskes on RealClimate.org: Hiatus or Bye-atus?

The idea that global warming has “stopped” has long been a contrarian talking point. This framing has found entry into the scientific literature and there are now numerous articles that address a presumed recent “pause” or “hiatus” in global warming. Moreover, the “hiatus” also featured as an accepted fact in the latest IPCC report (AR5). Notwithstanding its widespread use in public and apparent acceptance in the scientific community, there are reasons to be skeptical of the existence of a “hiatus” or “pause” in global warming …. We have examined this issue in a series of three recent papers, which have converged on the conclusion that there is not now, and there never has been, a hiatus or pause in global warming.

Just go and read the post, and if you like, the links therein.

from ScienceBlogs http://ift.tt/1OiRdUh

You’ve heard much about the so-called “pause” or “hiatus” in global warming.

One of the implications of a multi-year “pause” in global warming is that the science of global warming must be somehow wrong, because with CO2 rising in atmosphere, due to human activity, how can the surface not warm? However, surface temperatures have been rising, but at a somewhat slower rate than at some other times.

The truth is that there is a lot of variation in that upward trending surface temperature value, measured as an anomaly above expected temperatures. Sometimes the variation pushes the rate of warming up, sometimes it pushes the rate of warming down. This has always happened, and will always happen.

So there was something of a lowering of rate of surface warming, but at the same time, no such reduction in rate of ocean warming. Most of the heat from global warming is added to the ocean, not the surface. So, the reality is, global warming has been continuing apace.

One of the factors involved in a slowdown is probably the fact that the Pacific Ocean has been absorbing more heat, for a longer period, relatively uninterrupted by large El Ninos (which reverse that trend), for longer than usual. This year’s El Nino is returning some of that heat to the atmosphere. But even before El Nino kicked in, we were having month after month of record breaking heat (with the very rare month not being a record breaker) for a long time.

Anyway, a couple of papers have recently been published that look once more at the “pause” and I wanted to point them out. The best way to get at these papers is to read the guest commentary by tephan Lewandowsky, James Risbey, and Naomi Oreskes on RealClimate.org: Hiatus or Bye-atus?

The idea that global warming has “stopped” has long been a contrarian talking point. This framing has found entry into the scientific literature and there are now numerous articles that address a presumed recent “pause” or “hiatus” in global warming. Moreover, the “hiatus” also featured as an accepted fact in the latest IPCC report (AR5). Notwithstanding its widespread use in public and apparent acceptance in the scientific community, there are reasons to be skeptical of the existence of a “hiatus” or “pause” in global warming …. We have examined this issue in a series of three recent papers, which have converged on the conclusion that there is not now, and there never has been, a hiatus or pause in global warming.

Just go and read the post, and if you like, the links therein.

from ScienceBlogs http://ift.tt/1OiRdUh