These are true long-shots. We need to drastically reduce emissions in a time frame that is becoming increasingly unrealistic. I don't pretend to know the solution, but part of it is going to have to be the global economy realizing our current level of consumption is not sustainable. Since that is not likely to ever happen, we should shift to a combination of emissions reduction + catastrophe mitigation (funding for building seawalls on vulnerable coasts, investing in new agriculture technology to help stave off famine, etc.).