In this essay, we describe some important themes in energy and environmental policy. There are two main reasons for our interest in these policies. First, such policies will likely be important in the coming decades as issues related to climate change and energy security come to the fore....

Limiting global warming to no more than 2°C requires global large-scale deployment of low-carbon and negative emissions technologies. This requires the development of new eco-innovations and the diffusion of new and existing ones. Existing portfolios of environmental and technology policy...

This survey reviews the empirical literature on the impact of environmental policy instruments on the rate and direction of technological change. The survey is explicitly focused on the empirical identification of the hypothesis to expect a stronger impact from market-based incentives than from...

We investigate how irreversibility in "dirty" and "clean" capital stocks affects optimal climate policy, from both theoretical and numerical perspectives. An increasing carbon tax will reduce investments in assets that pollute, and so reduce emissions in the short term: our "irreversibility...