Land scarcity arising from such a policy would likely force an increase in agricultural productivity. The cost estimates for the newly protected lands have a big impact on the overall results. With higher assumptions, the program costs more than it achieves, even when the benefits of avoided climate change are included. With lower assumptions it only barely passes, making $1 spent achieve slightly more than a $1 worth of good.
However, Hussain and Markandya note that the main reason for this program would be to enhance biodiversity conservation; our current methods of estimation do not fully capture those benefits, so these estimates could be an underestimation.
Forests are one of the main homes to biodiversity. The final program Hussain and Markandya propose seeks to prevent all dense forests from being converted to agriculture over a 30-year period. The academics do not attempt to assess the political viability of such an approach. To use the same measure as above, it would save more than seven times the area of Spain in tropical forests.
The benefits are very high, but there is considerable uncertainty about the costs. With estimates they find reasonable, the benefits exceed the costs even without including the CO2 storage value, and the solution is attractive because it will get a minimum of $7 back on the dollar.
The research laid out by Hussain and Markandya points to a range of concrete options we could take, if we’re serious about responding to this challenge.
What’s your view? Are these investments that you think that policy-makers and philanthropists should prioritize? Have your say in the poll:
Remember: In each of the stories published to date, there’s a poll, and you can still go back and vote in all of the polls today. Each day, as well as publishing a new topic of research, I respond to your comments and update you on how readers are prioritizing pieces so far. See which priorities are currently the favorites of Slate readers.
Tomorrow, we will look at the other big environmental issue: climate change. We’ll draw from four different research papers written by teams of respected climate economists, examining the full range of policy options beyond those that we hear the most about.
In this series, Bjorn Lomborg explores the smartest investments to respond to global challenges—and readers get to have their say. See the earlier articles here. And read Bjorn’s responses to readers and find out which investments are currently at the top of Slate readers’ priority list. Be sure to vote in the poll at the bottom of each article.