There are some major things that need to happen to solve global warming (other environmental issues aside.)
-Dfine agricultural/development areas. Ideally, this would be based on a combination of soil productivity and local populations for export. Also ideally, this should see a pretty big reduction in current agricultural areas.
-Switch all power generation away from fossil fuels. The vast majority of this should be in the form of Solar, Hydro, and Wind power, but densely populated areas could see some nuclear power, at least for the time being.. This would be made much easier if overall energy consumption was decreased, which is very much possible by pumping up electricity prices (which also helps fund these projects.)
-Switch transportation to be environmentally friendly (generally.) This will inevitably have to mean far less cars, and big improvements in public transport infrastructure, especially in places like North America, in the form of city transport (lotsa busses, trams, metros,) and intercity transport (rural transportation, interurban train and bus service.) On top of this, any remaining automobiles need to be either electric, or some form of renewable combustion or fuel cell engine (hydrogen, biodiesel, etc.)
On top of this, long distance shipping should be discouraged, and any long distance shipping should be either achieved by electrified freight trains, or wind-based sea vessels.
-Improve waste disposal so it reuses as much material as is possible. Try to achieve 100% recycling, compost organics (food waste & sewage) into fertilizers and fuel. Basically make landfills obsolete.
-Reduce concrete use. Use alternatives, reduce the amount of concrete necessary in building construction, and increase the lifespan of buildings.
That's all I can think of now. Some pretty basic things that'd reduce GHG emissions hugely.