...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...

The tractable general equilibrium model developed by Golosov et al. (2014), GHKT for short, is modified to allow for stock-dependent fossil fuel extraction costs and partial exhaustion of fossil fuel reserves, a negative impact of global warming on growth, mean reversion in climate damages,...