My amateur-level knowledge of geological history suggests that a warmer, wetter, and higher-CO2 atmosphere--such as that found in the Carboniferous Period prior to the rainforest collapse or the Middle Miocene prior to its extinction event--would support greater total biomass and a wider variety of viable species than current conditions.

In other words, the climate change that everyone is frantically trying to reverse would probably be better for the biosphere, and for humanity in general. For specific humans with well-established property interests on or near the oceanic coasts, the current climate trends will be disastrous.

If every organism on the planet had a vote, Earth would overwhelmingly be in favor of more anthropogenic CO2 emission. Of course, only the humans understand the potential downsides, such as temperature-triggered methane clathrate decomposition that may have already been a contributing factor for two planetary extinction events, including the Permian-Triassic (the worst).

~Obviously, the solution is to ignore the CO2, dig up all the methane hydrates, and turn them into useful plastics before the temperate rise causes them to melt.~

Such conditions emerged over very large timespans in which life had plenty of time to evolve in response. What you are talking about is the same changes but over a few hundred years...this would be absolutely DISASTROUS for life. Rising CO2 is already acidifying the oceans and we've already seen symptoms such as coral bleaching.

That is a hard question to answer, because my answer is biased (I live now, so I am biased to think now/recent-past is the best climate). But I do think the 19th/20th century was the most ideal climate possible for the human race. I would speculate it is no coincidence that the industrial revolution occurred so quickly, in part due to a verdant climate.

Google for anthropic bias or anthropic principle

Climate changing slower than humans give birth or starve, plus lack of petroleum age mobility, will result in this bias.

The one we like the most is better. We're used to a specific kind of climate for the last few thousand years, so let's try going back to that first.

Which one, 11000 years ago there were two miles of ice where I sit typing this. That kinda sucked for the locals. Left some cool hiking terrain.

http://en.wikipedia.org/wiki/Little_Ice_Age

This caused the death of millions when Genghis Kahn's men needed to immigrate somewhere due to climate change. We'll probably kill a similar percentage of various cities in the next big climate change.

The climate never has been constant and there is no "the official correct climate".

Trying to force people is likely to result in war which is likely to, overall, kill more people than letting it do its thing. We're running out of stuff to economically burn anyway. Its not like we're only 0.0001% burned up or even 10% burned up. Soon enough, talking about rationing something we no longer have access to burn will be quite pointless. Voluntarily saving some for later is likely to have a pretty decent economic impact. Social engineering by modification of tax law is likely to save more centimeters of ocean than any strictly environmental or behavioral regs.

Well, you force people exactly by the means you describe.

Then again I think that maybe it's a time for an "official climate" because it's the decentralized decision making that's screwing as over wrt/ anthropogenic climate change. Someone has to make those regulations and enforce them.