World leaders in CO2 now talk climate change

Today you can read headlines that would have been unthinkable four months ago. American and chinese political leaders discuss what their nations can do about climate change. The new U.S. Secretary of State has invited China to join her country in working against global warming. China and the U.S. are the global leaders in CO2 emissions. China has moved into the overall league lead with its numerous coal-burning electric generation plants. Meanwhile, don't we need to reclaibrate all the estimates based on the current real-world status of the recession/depression? I suspect nearly all economic activity has slowed a lot, save perhaps ethanol production for human consumption.