“So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change, with all its dire consequences: shifting climatic zones, freshwater shortages, eroding coasts, and ocean acidification, among others.”
Severe climate change, eh?
1. More CO2 (with lower plant water consumption) mitigates the “drought” issue. A win for more CO2.
2. Shifting climate zones. So far on (since 1982) average the earth has gotten a lot greener on average, despite a lot of forest burning. Seems like a win.
3. Fresh water shortages. As Jim Steele loves to point out – it doesn’t take a lot of tinkering on the ground to mess up hydrology and man is pumping a lot of ground water. At least they won’t need as much water for irrigation.
4. Eroding coasts. This is a complex issue with a number of man made causes. Will making the ocean less alkaline affect affect it significantly? This one we’ll leave on the table since the amount change and the reason for the warming contribution wasn’t quantified.
http://www.eea.europa.eu/data-and-maps/figures/decline-in-ph-measured-at/ome01/image_original
5. Acidification of the Ocean. It will get less alkaline – but it won’t become acid. PH is one of those log function thingies and it is going asymptotic. It appears to be impossible to drive the PH below around an 8.04 average but if you want to claim 8.02 by 2100 go ahead. Still alkaline.