Wednesday, March 07, 2007

Piling On

I guess this is why the global warming crowd has tried to change the debate by calling the 'problem' climate change and not global warming.

Now the hysterical world is ending chicken littles can use any random anecdotal story about severe weather to prove their point. It's a clever strategy. They are never wrong. Any news story about the weather helps them. If its 72 and sunny, there is no story and no one thinks about the weather. Win, Win.

Now give me more grant money so I can continue to scare the hell out of everyone!

The weather has been random, unpredictable, and often violent for thousands of years. I don't think it has gotten any worse in the past 20.

5 Comments:

Anonymous G Shane Lewis said...

I prefer "global climate destabilization". It has that vaguely ominous ring to it that keeps those tasty grant dollars flowing.

You've done a good job of drawing attention to some of the limits of subjective validation. Humans aren't very good at intuitively quantifying changes to complex systems, especially those that take place over long timescales. So, they see hobgoblins in spurious events because they're looking for them. Of course, after railing against subjective validation based on a crappy sample size, your "I don't think it's gotten any worse in the past 20" is subject to some of the same problems.

Basic physics predicts more energy in the climate system. And in fact, it's now impossible for scientists to simulate the current state of the climate without a model that shows the extra energy from absorptive gases. Instrument measurements show more energy in the climate system.

There are a number of ways and places this extra energy can manifest. More extreme weather events - more droughts, floods, bigger storms, you know the list of course. But so far we're just talking about one degree globally on average - not enough to drown out all the other natural cycles of the planet. And most of that change has been at the very high latitudes.

So let's suppose you've been in a place where the local climate hasn't really changed all that much recently. Does that give you good insight into the dynamics of the larger system? Better than, say, the modern instrument record?

9:26 PM  
Blogger Jeff said...

"And in fact, it's now impossible for scientists to simulate the current state of the climate without a model that shows the extra energy from absorptive gases."

Wait--are you saying that somehow SCIENCE can differentiate between extra energy resulting from absorptive gases, and, say, extra energy resulting from increased solar radiation? Do tell!

7:44 AM  
Anonymous Anonymous said...

Over the past few million years, change in solar radiation falling on the earth's surface has been the biggest driver for long-term climate change. Changes in radiation are mostly a function of elements of orbital dynamics. (One simple example: the Earth is currently closest to the sun during Southern summer.) Different parts of the globe contain different ratios of land, water and ice, which means they reflect and absorb radiation at different rates. There are different cycles for these orbital elements, including eccentricity of our orbit, axial tilt, axial orientation, operating at different timescales. But for the big cycles, when all these elements act in concert to put the most solar radiation on 65 degrees N, ice ages tend to end. This theory (Milankovitch cycles) was first published in 1976 and had gained wide acceptance by the early 1980's.

Sans extra forcing of the climate system by greenhouse gases, you can run the elements of orbital dynamics forward in time to predict the broad brush direction of average temperature changes. These predict a cooling, although there are still some unresolved problems with the models, and they don't do a good job of predicting how much cooling we should expect or when. It's a complex, chaotic system.

In the early 90's, scientists with undisclosed conflicts of interest in the pay of ExxonMobil produced papers showing that while satellite data confirms that global warming is real and can't be explained away using elements of orbital dynamics, maybe the sun is just getting brighter. This would result in more radiative forcing without the need for help from greenhouse gases or a particularly "hot" orientation. But it turned out they'd cooked their data and solar output hasn't been increasing.

The incident radiation hitting the Earth's outer atmosphere is about 1366W/sqM, and it really doesn't change by much. In fact, prior to the satellite era, changes were benneath our ability to detect. Total output does vary by about 1.3W/sqM over the course of the 11 yr sunspot cycle, but longer cycles haven't been directly measured yet, and proxy measurements for incident radiation aren't terribly reliable. A 2006 study and review of existing literature, published in Nature, determined that there has been no net increase in solar brightness since the mid 1970s, and that changes in solar output within the past 400 years are unlikely to have played a major part in global warming.

4:24 PM  
Blogger Jeff said...

Dear Anonymous,

Allow me to boil your argument down to essentials:

"Over the past few million years, change in solar radiation falling on the earth's surface has been the biggest driver for long-term climate change... It's a complex, chaotic system... In the early 90's, scientists... produced papers showing that while satellite data confirms that global warming is real and can't be explained away using elements of orbital dynamics, maybe the sun is just getting brighter. This would result in more radiative forcing without the need for help from greenhouse gases or a particularly "hot" orientation."

Thank you for sharing your expertise.

Sincerely,

Brit Hume

10:12 PM  
Anonymous Anonymous said...

Well Brit, I'd have to say that you -- hey, who turned my mic off?

9:23 AM  

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