[1] CO2 absorbs IR, is the main GHG, human emissions are increasing its concentration
in the atmosphere, raising temperatures globally; the second GHG, water vapor, exists
in equilibrium with water / ice, would precipitate out if not for the CO2, so acts as a feedback; since the oceans cover so much of the planet, water is a large positive feedback; melting snow and ice as the atmosphere warms
decreases albedo, another positive feedback, biased toward the poles, which gives larger polar warming than the global average;
decreasing the temperature gradient from the equator to the poles is reducing the driving forces for the jetstream; the jetstream's meanders are increasing
in amplitude and slowing, just like the lower Missippi River where its driving gradient
decreases; the larger slower meanders increase the amplitude and duration of blocking highs, increasing drought and extreme temperatures — and 30,000 + Europeans and 5,000 plus Russians
die, and the US corn crop, Russian wheat crop, and Aussie wildland
fire protection fails — or extreme rainfall floods the US, France, Pakistan, Thailand (driving up prices for disk drives — hows that for unexpected adverse impacts from AGW?)