Some economists have raised the question as to whether it makes more sense to pay for mitigation (reducing the emissions of greenhouse gases) or adapting to climate change. Everyone agrees we need to adapt some, as sea level rise up and changes in temperature and precipitation will require new water policies and shifts in agriculture.
Ironically, paying for adaption makes most sense if accompanied by an aggressive reduction in greenhouse gas emissions, to keep cumulative temperature increase below 2 C (2oth and 21st century): reducing GHG emissions by 2015 to 2005 levels or even lower, and reducing GHG emissions 60% or more between 2015 and 2050. This means that American per capita reductions will need to be well over 90%, unless we wish to continue the current practice that we who are richer get to emit considerably more than our share.
John Holdren has calculated that if we pay the costs of preventing catastrophic climate change (though the polar bears and coral reefs are committed to extinction soon pretty much in any scenario), we will reach 2050 levels of prosperity in 2051 or 2052.
He doesn’t count the cost of adapting to severe rather than catastrophic climate change.
If we don’t keep cumulative temperature increase below 2 C, many adaptations become too expensive. If we reach 2 C by 2050, as we are likely to under business as usual, there is a decent chance (almost a certainty?) that there will be a cumulative sea level rise of 1 meter (from 2000 levels) by some time in the third quarter of this century. This means that enormous levees would have to be built to assure that agricultural water is available in California south of the delta (east of San Francisco). But if sea level rises that rapidly, the next meter rise may take only 25 or 30 years, and it won’t make sense to build the second set of protections which will last only a short amount of time, so it won’t make sense to even build the initial levees.
Adaptation makes most sense if we confront climate change, not if we avoid dealing with it.
Of course, there will be enormous costs before we reach 1 meter sea level rise. Some are thinking about adaptation, but such considerations are not prevalent or serious enough given how rapidly the climate is changing, and is likely to change in the next few decades.
These calculations sound about right to me, but they omit the economic benefits of moving to a more planet-friendly society. Thomas Friedman of the New York Times argues that green development is the wave of the future and the next big growth industry. I think he is right, although he is still thinking in terms of traditional economic growth. I’m thinking more about benefits that offset costs and possibly lost jobs. Retrofitting buildings so that they have a better carbon footprint, for instance, is a huge task which, while it will have a lot of costs, will also create a lot of jobs. So will rebuilding our transportation system to reduce its carbon footprint.
It’s hard for a lot of people, especially politicians, to see these possibilities because they are stuck in old ways of thinking—transportation means the internal combustion engine; buildings mean lots of incandescent lighting; etc. Finding alternatives and putting them into place will be challenging and costly, but there should be offsetting benefits. (I cite transportation and lighting because I know that alternatives already exist in both areas. I’m sure there are many others that I don’t know about where alternatives either exist or can be developed in time to do some long-term good.)