Tuesday, July 14, 2009
Noticing the Weather
There is the normal pot-calling-kettle-black complaint about talking about so short a period (a decade), too short to derive a valid trend. But, of course, the Warmie true believers use very short time periods too. Since 1900, they chart, temperatures have gone up and down but ended up about .6 degrees C warmer. But if you look at the past 1000 years, you notice that the global mean temperature goes up and down and it was much warmer just a few centuries ago. We're just catching up. Back to the Real Climate article.
After raising the possibility that the recent decade of cooling might not really exist, the Warmie writes:
...only time will tell if it’s real. Regardless, it’s important to note that we are not talking about global cooling, just a pause in warming.
(Emphasis in the original).
Ah, just a pause. Warming will resume. It's not cooling, though, even though it's cooler now. How can he be so blind yet so sure? There is no evidence given, just hypothesis.
To be fair, there may be some actual evidence (as opposed to computer simulation) in the paper the article talks about. I couldn't find it.
We hypothesize that the established pre-1998 trend is the true forced warming signal, and that the climate system effectively overshot this signal in response to the 1997/98 El Niño. This overshoot is in the process of radiatively dissipating, and the climate will return to its earlier defined, greenhouse gas-forced warming signal. If this hypothesis is correct, the era of consistent record-breaking global mean temperatures will not resume until roughly 2020.
But the article is unconsciously honest in its closing paragraph:
What do our results have to do with Global Warming, i.e., the century-scale response to greenhouse gas emissions? VERY LITTLE, contrary to claims that others have made on our behalf. Nature (with hopefully some constructive input from humans) will decide the global warming question based upon climate sensitivity, net radiative forcing, and oceanic storage of heat, not on the type of multi-decadal time scale variability we are discussing here. However, this apparent impulsive behavior explicitly highlights the fact that humanity is poking a complex, nonlinear system with GHG forcing – and that there are no guarantees to how the climate may respond.(Second emphasis added).
Let me paraphrase that last sentence: Regarding increased CO2 in the atmosphere, we have no freakin' idea what it will do to the global temperature.
Here is an undisputed graph of the radiative forcing CO2 can do now. We're at the end of the squiggly blue line. Not that sensitive. Looks like between less than a half degree to less than two degrees is possible by 2300, except that the increased water vapor from the past slight warming has been acting like a negative feedback system and cooling the planet.
Labels: Global Warming; Pause in Warming
Certain bird species wintering farther north?