New Study Suggests Global Warming Will Be Kind to the Northwest: Why We Should Still Act

A recent study published in Science Magazine by Solomon Hsiang and others completed an economic analysis of the economic effects of global warming by the end of the century (2080-2099). They considered a range of impacts, including agricultural, property and violent crime, mortality, and coastal issues (sea level rise, storms), among others.  Doing so, they created a map of total economic damage, shown below (in percent of Gross Domestic Product, GDP).  Red and orange colors signify global warming will cause damage, while green colors indicated that global warming will be an economic plus.  They drove their economic models with output from climate simulations.

The bottom line is that cool states come out ahead, while warmer locations are hurt by global warming. Not good for the southeast states (particularly Florida and Texas) and most of Arizona.  But generally quite good for the Pacific Northwest.   Only a thin strip on the eastern slopes of the Cascades has a slight negative impact and the coastal zone does quite well.

Hsiang et. al, 2017 Science Magazine

You can see some of the component contributors below.  For our region, big gains in agriculture from the added warmth.  Large drops in mortality (cold is a killer).  Far less energy costs for heating.  No increase in coastal damage because our land is generally well above sea level.

Hsiang et. al, 2017 Science Magazine

It is interesting to compare the Hsiang et al economic analysis with one examining meteorological threats from global warming  found in one of my earlier blogs (see below).  Each color represents a different threat (e.g, red would be storm surge from hurricanes).  The white area indicates one area of little increase in threat:  the Pacific Northwest.

So the Northwest is an area that should do particularly well under global warming-- we will have plenty of rain, a bit of warming will be welcome over much of the area, our storms should not become more severe, and sea level rise is not much of a problem.  Hsiang et al suggests we will come out ahead economically.    

But I am not sure that paper considers all the costs.  Warming will bring less snowpack in the mountains as the freezing level rises, so less snow melt available in the summer.  Thus, we will have to either learn to be more efficient with water (e.g., more drip irrigation in eastern Washington) or build expensive dams and reservoirs (costing billions of dollars).

Although the total precipitation will not change dramatically (small increase), we do expect the heaviest events to bring 30-40% more rain...and thus more flooding.  Thus, we will need to move folks away from rivers, something that could easily cost billions more. And away from steep slopes (like Oso).

Our east-side forests are in terrible shape due to fire suppression and poor forest practices (clear cutting rather than thinning, leaving slash, etc).  As a result, we have seen increasing number of large, intense fires, and local warming will make this worse.   We thus need to spend billions more to restore our forests to better shape to prepare.

So global warming will cost us in these and other ways; as a result, the benefits of lower heating bills, less ice/snow on the roadways, and enhanced agriculture will be balanced in part by steps needed for adaptation.

Global warming will probably end up being a wash for us.  But this will not be true of those living in warmer sections of the U.S., and for much of world's population that lives in he subtropics (such as India, SE Asia, Africa's Sahel, and Mexico).  Thus, the moral imperative is for us to reduce our carbon emissions, while at the same time building the climate resilience of the region.



from Cliff Mass Weather and Climate Blog http://ift.tt/2tIjkpZ