Except cap and trade programs have done nothing to prevent or curb climate change. Oil companies just buy carbon offsets and continue polluting. Solar still depends on billions in subsidies to be viable, as with many other renewable energy sources. Solar is also extremely inefficient. It costs around 8 times more to output the same energy compared to natural gas for example. We've already invested billions in solar, and we've barely made a dent on solar costs. Oil is very cheap and affordable to the poor, which explains their continued use in the developing world over renewable energy.