[amazon_link id=”0262029189″ target=”_blank” ]Why Are We Waiting: the logic, urgency and promise of tackling climate change[/amazon_link] is Nick Stern’s second book on this subject, the first being [amazon_link id=”1847920373″ target=”_blank” ]A Blueprint for a Safer Planet[/amazon_link]. In the new book he aims to combine fear and hope – fear of the consequences of not taking big steps now, and hope that the need to change is an opportunity for new technologies and growth.

[amazon_image id=”0262029189″ link=”true” target=”_blank” size=”medium” ]Why are We Waiting?: The Logic, Urgency, and Promise of Tackling Climate Change (Lionel Robbins Lectures)[/amazon_image]

The first part of the book, “A Planet Between Peril and Prosperity,” sets out these two elements. Stern is at the gloomy end of the range of views about the likely rise in mean global temperatures and the consequent economic and social risks. Unless the world acts within a decade or two, the window for limiting the temperature rise to a manageable 2 degrees C will be closed, he says, before proceeding to dangle hope with a chapter about the potential for a “new energy-industrial revolution.”

The second part of the book is an interesting challenge to climate change sceptics (of course) but also to some of the economists who are less pessimistic. Stern challenges the application of economic methods that assess the costs and benefits at the margin – inappropriate he rightly argues when you are discussing big changes. He has a chapter discussing the flaws in the conventional ‘integrated assessment models’ used in the literature. Stern argues: “They have assumed strong underlying growth, plus only modest damages from big increases in temperature, plus very limited risk.” If you disagree as he does with all three assumptions, the consensus forecasts look Panglossian. A final chapter in this section assesses the debate about ethical assumptions and how these are captured in the modeling, a debate first triggered by the Stern Review. His critics argue that he makes an extreme assumption about the right discount rate to use to assess future costs and benefits; but he has not changed his view.

The third and final part is about political economy – why the negotiations are so hard, how to get fast-growing developing economies to sign up to urgent action, why is everything so slow? The book argues that this is the result of the analytical errors he sets right in part 2, and psychological barriers to change, and a communication deficit. But surely it’s much simpler? Nobody – person or country – has an individual incentive to bear the short term cost of change, while the costs of climate change are uncertain, 20 years into the future, and a collective problem. It will take an extraordinary politician to solve the global collective action problem in advance, rather than reacting to events. So the book concludes, “Why are we waiting?” I am not sure the market is waiting – there seems to be a lot of energy innovation under way. As for policy, surely we need individual nation state governments to do what they can through carbon taxes, or plastic bag taxes, or policies to ‘green’ power generation – and not wait for an all-encompassing international agreement?

This is not to say Nick Stern is wrong to be so concerned. The outcome he fears clearly has a non-zero probability even if you don’t agree with him. So I’m all for action. Anybody who is interested in the economics and political economy of climate change policy will want to read this book.