Damien Broderick wrote:
>
> At 01:19 PM 11/21/01 -0500, Mike Lorrey wrote:
>
> >> < roughly follows a 1,500-year pattern, based on analysis of the past
> >> 12,000 years. But the difference from the top of the cycle to the bottom is
> >> very small, with less than a 0.1 percent difference in energy levels >
> >>
> >> I.e., +0.00007% per year.
>
> >Excuse? How does 0.001 suddenly get an extra few zeros tacked on? I
> >assume you meant to say 0.0007%, and not 0.00007%,
>
> I dunno, 0.1 / 1500 = 0.000067 where I come from.
>
> That's assuming the reported solar effect is spread out over the entire
> 1500 years, and isn't meant to be c. 0.1 percent difference *per year*.
Ah, okay, so we can average it out to an average discrepancy of +/-
0.0005 each year. The difference from peak to trough being 750 years
apart, each year would provide an average of 0.0005% more solar flux.
Note that the heat, all else being equal, is cumulative. If the earth
radiates 50% of solar flux, that still means that 0.00025% more of the
input hangs around each year till the next, etc. If the increased flux
causes other greenhouse amplifiers to increase in function, then the
earth retains more heat and warms more than, say, the moon would.
Furthermore, note that this percent is based on the difference between
the background radiation of ~5 deg K and full on sunlight of about 550 K
in orbit. Thus, a 0.001% difference from 1250 AD to 2000 AD is equal to
about a half a degree Celsius of solar flux in space, which, given
natural greenhouse performance of earth's atmosphere and ecosystem,
would result in a variance of several degrees C over that period on the
earth's surface.
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