[Coral-List] [SPAM] NASA - NASA Study Finds Increasing Solar Trend That Can Change Climate

[Charles Delbeek]

At 08:27 AM 11/17/2006, you wrote:
>Other factors that are thought to play a role include the 
>development of agriculture over the last few thousand years and even 
>the heat-trapping effects of high altitude contrails (observed 
>during the flight groundings post 9/11).

Actually a recent NOVA program showed that surface temperatures over 
the US actually increased after 9/11. This was thought to be due to 
the LACK of contrails after 9/11. The theory is that the contrails 
were blocking solar incidence and if it were NOT for the presence of 
these contrails over the US, surface temperatures might actually be 
higher than they currently are. On the flip side, the decrease in 
solar iradience affects vegetation growth and hence photosynthesis 
which of course, affects CO2 uptake rates. This is the effect now 
known as "Global Dimming", where the amount of light actually 
reaching the planet's surface has decreased over the last century. On 
the flip slide, this effect may actually be tempering global warming 
i.e. things could be much warmer without it.

This is a classic Catch 22 situation ... remove global dimming from 
the equation and you get more light but also more heat, leave it be 
and you get less light and but less heat, and lower photosynthesis rates.

Sincerely,


J. Charles Delbeek M.Sc.