I’ve been looking for a short summary of the case against taking strong actions now to control greenhouse-gas emissions, to use as a teaching case. Not having found one, I made one up. I’d be interested in corrections and suggestions.
Please note: This is supposed to be a statement of the case as its proponents make it, not a neutral review of the facts and options. What’s written below does not reflect my own thinking on the question, for what little that thinking might be worth. So please don’t tell me that you find some of the statements below absurd. What I’d like to know is whether they’re accurate as depictions of the case as it is actually made, e.g., by Bjorn Lomborg and the “Cooler Heads Coalition.”
Thus I’m especially interested in three sorts of errors in the material below:
1. Claims that aren’t in fact made by opponents of controls.
2. Misstatements of the arguments.
GLOBAL WARMING: The Case for Inaction
1. The science of global warming is unclear:
The historical temparature record is debatable.
The extent of the human contribution is unknown.
Projections of mean temperature increases vary widely.
Projections of how that change will be distributed between currently warm and cold regions, and of its impact on, e.g., precipitation patterns, are even less reliable.
2. Even if we knew the climate science, that still wouldn’t tell us about the impacts on humans and other species:
The results will be favorable in some places and unfavorable in others.
The mix is unknown.
Humans and their societies adapt to change by changing their behavior.
Other species adapt to change, or fail to, in a constant Darwinian process. It’s not obvious that increasing the rate of change will have on balance bad rather than good impacts.
3. Assuming that global warming is happening, that one of its causes is human activity and in particular the release of greenhouse gasses, and that its net impacts are bad, most of those impacts occur in the far future. That makes taking current action to prevent those future impacts a dubious proposition.
It’s rational to discount the far future compared to the near future because resources not spent now can be invested, creating future value. That applies to building factories, making scientific discoveries, and educating children.
If the money that would be required to implement strict controls on greenhouse-gas emissions were instead expended on, e.g., providing clean drinking water and female literacy for very poor countries in Africa and Asia, the suffering averted would far outweigh the benefits of having a somewhat cooler planet a century from now.
World standards of living have been rising sharply for the past 200 years, and there is no evidence that the growth in living standards is slowing down. Imposing costs on the current population of the planet to create benefits for far-future populations means transferring income from the poor to the rich.
The richer the world gets, the better it can adapt to whatever climate change occurs, as well as to more routine events such as hurricanes and tsunamis.
There may be technological fixes much cheaper than reducing greenhouse-gas emissions: for example, increasing the albedo (reflectance) of the Earth by putting light-reflecting particles in the stratosphere.
4. Even if we wanted to take action now, existing international institutions will not support an effective greenhouse-gas-emissions-control regime, and an ineffective one, such as proposed in the Kyoto Protocol, would generate large costs and small benefits.
5. Therefore, we should pursue a “no-regrets” policy: making investments now that make sense on other grounds — e.g., developing alternative fuel systems for automobiles — and that will also pay off in terms of controlling climate change if that turns out to be a problem, but not making huge sacrifices now to prevent we know not what.
My warm thanks to several readers for their suggestions. Here’s the revised document: