...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 Green Paradox states that, in the absence of a tax on CO2 emissions, subsidizing a renewable backstop such as solar or wind energy brings forward the date at which fossil fuels become exhausted and consequently global warming is aggravated. We shed light on this issue by solving a model of...