At SciFoo this weekend, Bjorn Lomborg gave me a copy of his soon-to-be-published new book, Cool It: The Skeptical Environmentalist's Guide to Global Warming. I just read it on the plane (it's a short book: you can finish it in two hours), and I think it's really worth paying attention to. He argues that although global warming is clearly happening and is human-caused, the debate over what to do about it has been polluted by way too much bad science, non-science, inflamed rhetoric and outright fibs.
When you look at the big picture, especially through an economic lens (which fully includes human costs and quality of life measures), he says that the usual approach of capping carbon output or putting high taxes on it costs too much for the benefits it offers. Instead, he thinks we should invest in research on renewable energy technology. Before I get to my own thoughts on that, let me list a few of the good points he makes about how much of the rhetoric over the effects of climate change doesn't stand up to scrutiny:
- Antarctic melting: The most likely effect of climate change would be to increase, not decrease, the amount of ice in Antarctica. That's because regardless of how warm the planet gets, the Antarctic will remain very cold (below freezing) for almost all the year. What determines the amount of ice in Antarctica is precipitation, not melting, and historically there's been very little of that--Antarctica is the planet's largest desert. Because the effect of climate change is to put more water vapor in the atmosphere, the effect will be more precipitation in Antarctica, deepening the ice layer that is already between a mile and two miles thick. The famous ice shelf that calved off the Antarctic peninsula a few years ago is on the northernmost (warmest) tip of the continent was sea ice, not on top of rock like the rest of Antarctica.
- Polar bears: Despite the heart-rending pictures of polar bears stranded on sea ice, global polar bear populations have increased dramatically over the past few decades. It turns out that the main threat to polar bears is hunting, not drowning. Of the 13 populations of polar bears in Canada, 11 are growing or stable. In one of the two population that are shrinking--the much-cited one on the West coast of the Hudson Bay--15 bears die each year due to drowning, while 49 are killed each year by hunting.
- Mount Kilimanjaro: Its famously shrinking glaciers have nothing to do with warming. The top of the mountain where they are never rises above freezing. Instead, they are shrinking due to evaporation (sublimation), caused by the drier climate in that part of Africa, something that's been happening for nearly a century.
- Rainfall: Certain parts of Sub-Saharan Africa will get drier, causing droughts. But most of Africa will get wetter. Overall, there will be more fresh water in the world, not less (the fact that it doesn't get to the right people at the right time is a water management issue, not a climate issue).
And so on. Lomborg doesn't believe that climate change isn't real and dangerous, he just argues that our policy debates on what to do about it are remarkably ill-formed because of exaggerated claims, bad (or non-existent) economic analysis and attention-getting anecdotalism.
My own position on all of this is one that I've come around to after much study and is exhibited in Wired's editorial priorities: it's time to put the debate over whether human-driven climate change is happening behind us and instead focus on technologies to decarbonize the economy. But climate change is only one of three strong reasons to do this. The others are:
Economics: Both the direct costs of oil and other carbon-based fuels, and the indirect cost of their "negative externalities" (pollution, etc) are only going to rise. That increases the economic return for alternatives, and shifting to those alternatives will allow the economy to grow more quickly over time.
Geopolitics: Propping up bad governments with oil revenues has a destabilizing effect on the world. Renewable sources are more broadly distributed around the world and will lead to more energy autonomy for most nations and less distortion of local and global politics due to the corrupting influence of too many natural resources in the hand of too few. (See Fareed Zakaria's "The Future of Freedom" for more on this argument.)
This three-leg case for investing in renewable energy technologies is the foundation of Wired's editorial philosophy on renewables, and can be found in everything from our original Al Gore cover package (before the movie), to our hybrid car cover (back in 2005) and our case for the virtues of expensive oil.
Where I differ with Lomborg is simply this: he thinks that the right path is to go light on a carbon tax (no more than $2/ton) and go heavy on government R&D subsidies for renewable technologies. I think we should have a somewhat higher carbon tax on the hopes that it creates sufficient incentives for the private sector itself to invest heavily in renewable technologies. Rather than spending the government tax money on federal research (which is best reserved for cases of market failure, which is clearly not the case in this greentech boom), use it to reduce taxes elsewhere. That is, of course, the Silicon Valley Way.