Rather than reaching an agreement on making "carbon credit" transfer payments to developing countries, lets just call previous aid payments "carbon credits". That's gotta be good for, what, 2 degrees Celsius.
We need to be careful not to apportion too much past aid though. We don't want to lower the planet's temps too much. I'm thinking changing the name of "aid" given by the West from...say... 1986 onwards should be about right. Should cool things down in a jiffy.
However, in order to keep temperatures up in really cold places like Winnipeg and Edmonton, a portion of Canada's aid given will be withheld from the accounting.
UPDATE: Due to the incredibly strong demand by folks in Winnipeg and Edmonton to raise their respective temperatures, it's been decided that not only will a portion of Canadian past aid be withheld from the accounting, a group of Western Canadians will actually go to various developing countries and take back the aid we have given.
UPDATE II: Great ideas in the comments. Heck, we can solve "global warming" today, right here!