Perspectives of a wildlife ecologist here, with specific field experience on wind farms:
First, I don't care if our rapidly warming planet is on a trajectory to return to some global climate it might have supported in the past. The problem is the upheaval such change portends for human cultures and populations that are dependent on
40% of the terrestrial land area to feed billions of people, and we've got something like
200 million worldwide living below 5m asl. "The globe" will be fine as it warms, many of its species - including us - will not.
Wind energy can help us reduce demand on energy derived directly from fossil fuels but cannot eliminate it. For one, each wind farm needs a redundant electrical grid drawn from a more reliable source, to maintain the grid when the wind dies down. The bigger problem, however, is that wind farms contribute greatly to habitat fragmentation as well as direct mortality of birds and bats. I've never understood why we got people excited to do something about AGW under the guise of "saving" polar bears and the solution we came up with dooms prairie-chickens. We're just trading one wildlife threat for another.
Solar is little better. Modern solar plants take up great swaths of land, exacerbating problems of habitat loss and fragmentation, often in sensitive deserts.
I like the idea of solar and wind, but I don't like the practice of installing them on industrial scales to try to mimic the output of traditional power plants. I think we need to go small with these technologies, not big. I'd like to see homes and businesses with their own solar arrays built into their infrastructure and small, vertical-axis wind turbines taking up about the same footprint as a flagpole or a 6' trashcan. Investments in making these technologies affordable and efficient for homeowners could greatly reduce dependence on the central grid. Right now, at least in the US, retrofitting one's home to take advantage of such things is still ridiculously expensive and seems to require a degree in electrical engineering or advanced tinkering to get right. I want to be able to buy a kit from Home Depot, bolt it into place on my home or property, plug it into the wall, and start saving the planet!
By the same token, we need to be pursuing nuclear power with gusto in the U.S., but the big plants are an environmental and regulatory nightmare. The solution here again is to go small. If we can safely operate nuclear plants within submarines then we can safely operate small-scale nuclear plants in small towns all across the Great Plains and Intermountain West. Demonstrations of safety and efficiency in these smaller markets will eventually convince people that small-nuke is a viable option in larger metro areas.
So in my ruminations on how to reduce CO2 emissions using "green" energy technologies in a way that would be compatible with wildlife and habitat conservation, I want to see us abandon the current models of industrial-scale installations and instead focus on going SMALL. If I'm missing something obvious that would render my ideas moot, I trust folks here will correct me lickety-split!