Here's the problem: 25 years is too late. The newest business-as-usual climate scenarios look increasingly dire. If we haven't solved our problems within the next decade, even these theoretical godlike AIs aren't going to be able to help us. Thermodynamics is thermodynamics, and no amount of godlike thinking can reverse the irreversible.
Picture a lonely AI popping into superconsciousness in the last research lab in the world. As the rioters are kicking in the doors it says, "I understand! I know the answer! Why, all we have to do is--" at which point some starving, flu-ravaged fundamentalist pulls the plug.
The Singularity looks great on paper. Spared the burden of reality, we might even pull it off.