whistlingwings wrote:The 1990 estimates were .15C - .3C per decade. The latest prediction is .2C per decade.
We are at the very low end of the range of predictions and the fear was for the high end. Which makes the rate of change at the low end of the range. And how fast can plants adapt. We have historically had big changes over extended periods and they adapted just fine.
But you hit on the biggest point of all. It is SUBJECTIVE.
whistlingwings wrote:Of course there is no "perfect" temperature....different temps mean positives for some things, negatives for others.
And the relative importance of them is subjective, which is why you could say if it were not subjective. The net effect is subjective.
whistlingwings wrote:which is why extinctions are predicted
So what? How much human suffering justifies avoiding something going extinct? It is a subjective value judgment and should not me made by some global warming death panel that decides what they think the acceptable level of harm from higher energy costs is. These subjective value judgments are to be made by our representatives and not by small panels of government bureaucrats and politically appointed "experts."
Personally and financially, I would do great with a big huge CO2 tax because nuclear power is the only viable option for a very low carbon emission future, but the suffering caused to the poor cannot be disregarded no matter how much it makes you feel better about yourself.
whistlingwings wrote:Fast change = humans will have to spend a lot of $ to adapt rapidly, eg importing water into dry areas as much of the western USA already has to do.
Or spend a lot less on heating bills up north. Crops will grow in places they have not. I've never got this assumption that it would mean more dry areas. The evaporation rate increases as temperature increases. And the simple mass balance is that what goes up must come down. More evaporation = more precipitation. Granted it will not be uniform, but on average there will be more precipitation. Humans are clever, they will adapt in a way that minimizes the negative impacts and maximizes the positive benefits. Look at the whole sale changes in the U.S. over the last 100 years. We change very rapidly.
Over that time period we have pretty much cut down and allowed to regrow all of the forests in the east and probably most of the ones in the west. Everything seemed to have adapted to that pretty well. Sure there were some extinctions, but people came out of the deal pretty good.
A politician thinks of the next election; a statesman of the next generation. A politician looks for the success of his party; a statesman for that of the country. The statesman wished to steer, while the politician was satisfied to drift.