You finally said something I agree with. Things like climate change, or even the recession or the US's debt problem, require long-term vision to tackle. Changing everything every four years just to spite the previous administration isn't going to accomplish anything in the long run.
On the other hand, leaders who stay in power too long tend to get ideas about never leaving and having their children take over when they die ...
There has to be a limit to government terms, but yes there should be some way for creating a group to tackle these long-term issues -- I'm afraid I don't know enough about current governments to know if there is already a method for this.