80% reduction in CO2 emissions by 2050? Is that even possible?

Let me see if I get this right. The Cap and trade legislation has as a goal to meet an 80% reduction in CO2 emissions by 2050, but China is exempt. China just passed us in total CO2 emissions. As of March 2009 China had 19.66% of the world population while the US had 4.53%. If we assume a population growth in the US of 26% between now and 2050  we are promising to cut our CO2 emissions to less than 69% per capita of what China emits today. And they can continue to emit as much as their production demands. Looks like a cold and dark future for us.