I do believe humans should be allowed to alter the climate purposely, as of right now we are altering the climate inadvertently thanks to our pollution.
In essence why wouldn't you allow people to make an attempt to reverse, fix, or at least improve the climate to negate the damage we have already done on any level.
It's believed that humans are already altering the climate. We should all work to minimize this from happening as much as possible. While some people debate that global warming is not caused by humans, there is little reason not to alter our behavior and practices, because we can all pretty much agree that we are polluting the natural world, and changing it. We are only borrowing the world from our children, and should work to treat it as kindly as we can.