Long story short: Pollution has 2 effects, a warming effect via
CO2 and a cooling effect (global dimming) caused by particles in the air which block the sunlight out. (smoke, ashes, soot etc.)
The easiest environmental measures have a bigger effect on the particles so the temparature has rissen lately.
Interesting detail: on the days after 11 sept., the temparature in the usa rose sharply with one degree celsius, cause of flight-suspension. When flights resumed it dropped to its normal levels.
Still, on average apperently, the warming effect is larger than the cooling effect. If we do nothing, then we'll end up with a slightly warmer world, where it will be extremely hard to breathe.
In such a world, two expressions will dissappear from human speech: "As free as air" and "Only the sun shines for naught".
Last edited by BrianPatrix; 06/24/07 11:41 PM.