I don't think we should, but here's some things that I think we're capable of:
* We could use atomic power, but not to replace oil: we irradiate or directly bomb the main global oil reserves so they are rendered unusable. Both Russia and the US have the power to do this many times over. That would mean World War III, probably. Which would also lower the CO2 levels.
* We can inoculate 10 or 20 people in densely populated areas with highly contagious virus, trigger a pandemic and see the numbers go down.
* We can simultaneously fund anti-vaccination groups, and decrease the funds for the public health organizations like the U.S. Food and Drug administration, worldwide. That could have the same effect, depending on how vicious the viruses we get are in the next 10 years. Super-flu would be fatal enough.
* We could use atomic power, but not to replace oil: we irradiate or directly bomb the main global oil reserves so they are rendered unusable. Both Russia and the US have the power to do this many times over. That would mean World War III, probably. Which would also lower the CO2 levels.
* We can inoculate 10 or 20 people in densely populated areas with highly contagious virus, trigger a pandemic and see the numbers go down.
* We can simultaneously fund anti-vaccination groups, and decrease the funds for the public health organizations like the U.S. Food and Drug administration, worldwide. That could have the same effect, depending on how vicious the viruses we get are in the next 10 years. Super-flu would be fatal enough.