Posted on 04/23/2009 8:38:35 PM PDT by cogitator
1st paragraph (with link to abstract):
"Our recent paper Climate response to regional radiative forcing during the twentieth century, has generated some interesting discussion (some of it very 'interesting' indeed). So this post is an attempt to give a better context to the methods and implications of the study."
Yet more aerosols: Comment on Shindell and Faluvegi
Most intriguing paragraph:
"In the absence of increasing greenhouse gases, our large historical emissions of sulfate precursors would have led to substantial cooling from sulfate, and the subsequent reduction in emissions would have brought temperatures back towards their previous level. So reduced sulfate does not cause warming in an absolute sense, only relative warming compared to a time when emissions were larger. Over the mid-20th century, sulfate precursor emissions appear to have been so large that they more then compensated for greenhouse gases, leading to a slight cooling in the Northern Hemisphere. During the last 3 decades, the reduction in sulfate has reversed that cooling, and allowed the effects of greenhouse gases to clearly show. In addition, black carbon aerosols lead to warming, and these have increased during the last 3 decades."
Thinking of you.
I scanned the story but hasn’t the push for celan air versus dirtier air in the 1970s caused a minor increase in warming. This is when clear skies lead to more sunlight hitting ground.
The real deal for me is the changes in solar radiation. The sun is far more powerful than CO2 levels.
Which is correct; and when sunlight hits ground, it converts to longwave IR radiation (heat), which is trapped by greenhouse gases.
bfl
Thanks, haven’t had time to answer the other thread and do it carefully. The sentence in this abstract that is most in need of improvement is “Our reconstructions broadly agree with historical emissions estimates”. I would like a quantitative comparison. Also would like to know where they got their emissions inputs to their model, might just be circular reasoning.
Two much better websites where real work is going on:
If you can't do the math with these easy numbers and figure out why, then you aren't taking the subject seriously, and I shouldn't bother trifling with an intellectual lightweight.
If you need more information on how the carbon cycle works, and a whole lot of information that proves human activity is causing the increase in CO2 concentrations in the atmosphere, feel free to ask.
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