Let me start off by saying that I believe GW is real and probably caused by humanity so I’m not grinding any axes here.
As I understand it GW will cause major melting of Polar ice caps and as a result of that the seas will become significantly colder and that there is a very good chance that the Gulf stream taking warm water to Europe will cease to function.
I would think that it would also alter other major currents and the El Ninio phenonomen.
Would the cooling caused by these effects in any way counterbalance GW and also have we any predictions for variations in the Earths orbit,Polar Precession and Solar activity all of which have caused significant changes to the worlds climate in the past?
I am reasonably intelligent but many of these things are a mystery to me.
Shutting down the Gulf Stream won’t affect global warming. The Gulf Stream takes heat from the tropics and dumps it into Europe. By shutting it down, Europe gets colder but the tropics get warmer. So while this might affect local climate change in Europe, it will not affect global warming as a whole.
Scientists spend a lot of time trying to identify feedbacks, both positive (self-reinforcing) and negative (non-reinforcing). I can’t speak much on the subject as a whole, but I know that even in the mid-90’s they were doing a lot of research on these feedback systems.
As far as orbits and precession are concerned, these have time scales too long (thousands of years) to impact our environment on the scale CO[sub]2[/sub] impacts our environment (tens of years).
Solar activity is a big unknown. We now have satellites that track solar output before it hits Earth. It’s been pretty constant since 1980 and probably pretty constant since 1850 (based on historical sunspot data), but we can’t be 100% sure. The IPCC currently estimates the effect of CO[sub]2[/sub] to be about 12x the effect of solar activity, with all the other anthropogenic effects (CH[sub]4[/sub], NO[sub]x[/sub], O[sub]3[/sub], sulfate, aerosols) balancing each other out.