[adamsjas]

The interesting conclusion this Article is careful to avoid mentioning is that decreasing pollution reduces the "global dimming" and therefore increases "global warming".

And the global dimming, was for a large part the result of eastern block industrial practices.

This reduction of dimming, due to particulates in the atmosphere since the 1980s, especially near cities, would probably account for the largest part of the so called "Global Warming" which is measured mostly near cities.

So the global warming measurements are caused by a reduction in pollution? You would think they would have the honesty to at least address this issue in their study.

[Pete from Shawnee Mission]

Good thing we do not burn wood for fuel anymore. Think of the dimming we would get.

If I understand it correctly, we are also at Solar Maximum and are receiving more sunlight than normal. Should make up for the dimming, at least in the cities...

[dr_lew]

On average, about 342 watts of solar radiation strike each square meter at the top of Earth's atmosphere.

This is possibly a misleading figure. The "solar constant" is 1373 watts/m2 . This measures the radiation falling on a square meter facing directly towards the sun. The total solar power falling on the earth is the solar constant times the area of the disk that the earth presents to the sun, i.e. pi r_earth squared . This is 1/4 the surface area of the earth, and the figure given is just 1/4 the solar constant, and it's an average only in the most abstract sense.

I think it makes a lot more sense to think of the disk of the earth and the variation of absorption etc. over this disk.

Note also that the solar constant varies by a whopping 7% between perhelion and aphelion, corresponding to an annual variation of 21 watts/m2 in the 342 watts/m2 "average".

[Outland]

When solar radiation is quantified in terms of W/m², is that averaged over the sun's entire spectral output, a specific bandwidth or is it a peak measurement over the entire bandwidth?

Obviously, the sun's output covers a wide bandwidth from RF to X-rays and the power output fluctuates wildly throughout that spectrum. Since "global dimming" is usually brought up in conjunction with "global warming", it is important to know what portion of that radiation comprises those parts of the spectrum that are converted to heat on Earth. Oddly, I never see that defined in articles such as this one.