Burning coal and oil has put SO2 into the atmosphere.
In the process of pumping gas and oil, quite a bit of methane has escaped into the atmosphere.
Chemical manufacturing has put CFCs into the atmosphere.
1) The failure to convert to nuclear energy for production of the electrical base load, at least since the demonstration of meltdown impossible reactor designs.
2) Policies, environmental and otherwise, that redistribute industries to developing countries that use cheap but inefficient coal.
Breathing. CO2 is a greenhouse gas, right? So if we stop breathing, problem solved.
exhaling
