This Challenge Paper consists of four separate contributions, updating key research papers from the 2010 Copenhagen Consensus on Climate Change project:

• An Updated Analysis of CO2 Emission Abatement as a Response to Climate Change, Richard S. J. Tol

• A Technology-led Climate Policy in a Chan-ging Landscape, Isabel Galiana and Christopher Green

• Climate Change: Climate Engineering Research, J. Eric Bickel and Lee Lane

• Market and Policy-Driven Adaptation, Francesco Bosello, Carlo Carraro, and Enrica De Cian

Introduction

In the 2010 Copenhagen Consensus on Climate Change (Lomborg, 2010), reduction of carbon dioxide (CO2) emissions received a low priority. This follows from the particularities of the Gedankenexperiment that is at the core of all Copenhagen Consensus exercises: there is a finite budget, that needs to be spent, on a separate project, informed by disjoint CBAs.

Climate policy does not fit in that mold, and CO2 emission reduction fits least of all.

Climate change is a big problem. In order to halt anthropogenic climate change, the atmospheric concentrations of GHGs need to be stabilized. For that, CO2 emissions need to be reduced to zero. This requires a complete overhaul of the energy sector. That is a big job. It should be done as long as the benefits exceed the costs. If it does not fit in the budget of the Copenhagen Consensus, then more money should be raised. Indeed, it would be profitable to borrow money if the BCR is greater than 1.