Climate change is evolving rapidly from a risk to be avoided to a reality to be mitigated. Despite a coordinated global campaign to reduce carbon emissions in the U.S. and other countries, too little progress has been made. The measures that have been passed – like higher auto fuel efficiency standards and tighter emissions rules for new power plants – will slow the rise of carbon, but they are not nearly enough to reverse it. Entrenched interests have thwarted stronger regulation. Without deep political change, carbon will continue to rise, and temperatures will rise with it.
It is therefore important that we come to a much better understanding of what changes will result and how quickly they will hit us. The speed of change is crucial: it costs far more to fend off a three-foot sea level rise that happens over 20 years than one that happens over 200 years. This week, the prestigious National Research Council stepped into the debate. It issued a report that examines the potential threats and estimated which ones are most likely to kick-in fast. (The National Research Council is an affiliate of the well-known and non-partisan National Academy of Sciences.)
The council concluded that the most likely near-term consequences of climate change are these:
In contrast, some of the more graphic climate change scenarios that have captured the public imagination are not very likely anytime soon. We're not going to see the Gulf Stream quit. We're not going to see the Greenland ice sheet or the western Antarctic ice sheet melt. We're not likely to see a quick and dramatic rise in sea levels.
Even so, the changes that the council predicts will have major economic and social consequences. Perhaps the biggest damage threat will involve our supplies of food and fresh water. For example, seafood will become scarce as falling oxygen levels in the ocean endanger the fish we eat and the smaller organisms on which they feed. Indigenous cultures that depend on fishing for their survival will face critical shortages.
More important for those in the U.S., the far-larger stock of food grown or raised on land will suffer. Extremes of heat typically reduce crop yields. New varieties of food crops will have to be developed that tolerate heat better than todays' varieties. Extremes of drought as well as losses due to flooding will be widespread. The main effect in the U.S. will be higher food prices rather than outright shortages. But many parts of the world operate close to the subsistence level with respect to food, and the effects in these places may be overwhelming.
The second major economic impact, if the report is correct, will be the cost of hardening our infrastructure and repairing damage to structures caused by extreme weather. New York must harden its subway system against storm surge, and California's governor is calling for billions to upgrade the water systems that slake Southern California's thirst. Cities and towns across the country will face large, unplanned expenses to repair storm damage and protect against damage yet to come. This can only be paid for by higher taxes, or by slashing other government spending.
The third economic impact implied by the analysis lies in the impact of climate change on national and global security. Countries with large, poorly-nourished populations will face heavy political pressure to protect their food security by encroaching on their neighbor's resources. Germany's campaign for lebensraum in the 1930's didn't end so well for the Germans or their neighbors. If nuclear-equipped China, India and Japan take a sudden interest in lebensraum to secure their food and water supplies, it will be catastrophic on a global scale.
The economic damage of climate change is more than enough to eclipse the 1-3 percent annual growth rate of a healthy economy. The cost of damages will be far greater than what it would have cost to avoid the problem by shifting our energy policy in the first place.
As we digest and discuss the National Research Council's analysis, we must reinvigorate our efforts to slow carbon emissions. Every bit of delay and decrease in carbon emissions helps us cope on both a national and global scale. Meanwhile, we must prepare for the difficult work of mitigating what we are too late to prevent.
David Brodwin is a cofounder and board member of American Sustainable Business Council. Follow him on Twitter at @davidbrodwin.