If some kind of cold fusion, which is harmless compared to hot fission that is currently used to run nuclear plants, could be utilized, it could really change the fossil fuel energy equation in the world.
Another carbon reducer would be using energy technologies that turn CO2 into a useable fuel. These technologies are out there. They just rearrange the carbon molecules in CO2 back into a form of fossil fuels. At least this would recycle carbon, instead of adding new carbon to the atmosphere.
If we do not make a major shift away from fossil fuels, I don't think we will save the life that is on our planet. At some point, the warming will make life unsustainable for many life forms on earth. The planet will survive, but most life will not.