NICOSIA, Cyprus (AP) — A prominent American economist says getting rid of fossil fuels by mid-century and making the switch to large-scale renewable energy sources and nuclear power offers the best chance of meeting the climate change targets set out by the Paris accord.

Columbia University Professor Jeffrey Sachs says the world's ways of producing and using energy need to change "much faster, much more dramatically" than political leaders looking to tap hydrocarbon reserves understand.

Sachs says the best approach is to set up interconnected power grids where emissions-free electricity from renewable energy sources in one region could be transmitted elsewhere.

Sachs was speaking Saturday at a conference in Cyprus on the climate change challenges faced by Mediterranean countries and the Middle East, including drought and crop failures.