...The optimal carbon tax reduces emissions from burning fossil fuel, both in the short and medium run. Furthermore, it brings forward the date that renewables take over from fossil fuel and encourages the market to keep more fossil fuel locked up. A renewables subsidy induces faster fossil fuel...

Optimal climate policy is studied in a Ramsey growth model with exhaustible oil reserves, an infinitelyelastic supply of renewables, stock-dependent oil extraction costs and convex climate damages. Weconcentrate on economies with an initial capital stock below that of the steady state of the...