reverse global warming

To reverse global warming, we must first "reduce greenhouse gas emissions.” So we must complete the switch to renewable energy sources such as solar, wind, and hydropower; electrify everything; increase energy efficiency; and use more sustainable agricultural practices. Changing consumption patterns is also helpful.

Second, we must remove CO2 from the air.  That includes the legacy CO2 we have already put in the air. This begins with reforestation and afforestation.  It continues with capturing CO2 directly from the air, combining it with gravel or seawater, biochar use on crops, no-till crops, and so forth.  

Third, we must darken Earth, to actually cool it. We may be able to reverse some ice loss.  But more, we need to return aerosols (calcite or sulfate, like volcanos) to the stratosphere, brighten clouds, thin cirrus clouds, and so forth.