David Hendry at Vox EU:
Climate change: Lessons for our future from the distant past, by David F. Hendry: Summary Climate change has been the main driver of mass extinctions over the last 500 million years. This column argues that current evidence provides a stark warning. Human activity is producing greenhouse gases, and as a consequence global temperatures and ocean heat content are rising. Such trends raise the risk of tipping points. Economic analysis offers a number of ideas, but a key problem is that distributions of climate variables can shift, invalidating stationarity-based analyses, and making action to avoid possible future shifts especially urgent.
Economic analysis offers many insights – externalities need to be either priced or regulated, and climate change is the largest ever worldwide externality. All approaches are affected by the possibility of abrupt changes and the resulting unknown uncertainty when distributions shift, making action more urgent to avoid possible future shifts. Adaptation is not meaningful if food, water, and land resources become inadequate. Conversely, mitigation steps need not be costly, and could stimulate innovation. International negotiations are more likely to succeed if the largest players act first in their own counties or groups – also creating opportunities for their societies as new technologies develop.
Planet Earth will survive whatever humanity is doing – the crucial issue is the effect of climate change on its present inhabitants. It is a risky strategy to do nothing if there are potentially huge costs when the costs of initial actions are small. The obvious time to start is now, and the obvious actions are the many low-cost implementations that mitigate greenhouse gases (see Stern 2008 for a list) – just in case.