If we can plant 30,000,000 trees in Ethiopia, then it can be done anywhere. The UN is also waking up to the fact that this could be the best possible global initiative. I certainly think so
All the deserts in the world can become thriving forests. In the process the world itself will warm significantly, but way more uniformly. With luck we will be able to release a lot of the CO2 locked up in thye /arctic and plenty of what is in the Ocean. Over time we may even recover the CO2 content to 1000 ppm from the present 400 ppm.
All this makes global terra forming very easy.