Adapting to climate change depends on site-specific knowledge

New research has put climate change in a more challenging – although not entirely discouraging – perspective: It's too late to avoid some unpleasant effects of global warming, such as a rising sea level and water shortages. But there's still time to avert the worst foreseeable consequences, such as an even larger sea level rise and even more extreme temperatures.

The National Center for Atmospheric Research (NCAR) in Boulder, Colo., made that point in a comprehensive study published in April. To quote the study's lead author Warren Washington, "This research indicates that we can no longer avoid significant warming during this century. But if the world wants to implement [drastic greenhouse gas] emission cuts, we could stabilize the threat of climate change and avoid catastrophe."

In other words, we're being challenged to adapt to significant climate change while at the same time making difficult economic adjustments to curb greenhouse gas emissions. There's plenty of discussion about curbing the gases and some discussion of adapting to what now seems inevitable environmental change. There's relatively little focus on how to deal with these two challenges simultaneously.

Getting the balance right will be tricky. The consequences of climate change already underway can be subtle. Melting icecaps can raise general sea level. But the actual rise along populated coastlines is not the same everywhere around the world. It depends on more than the volume of water in the ocean.

Fill a bathtub and note where the water stands along the sides. Now vigorously swirl the water with your hand. The pattern of flow will make the water stand higher at some places along the sides than at others. This happens in the ocean. If climate change alters ocean circulations, sea level will rise higher along some coastlines than you'd predict from just noting how much water melting ice contributes.

Another NCAR study published in late May showed how melting Greenland ice not only adds to seawater volume but changes currents to push water even higher along northeastern coasts of North America. Sea level there could rise 12 to 20 inches more than along other North American coastal areas by 2100. The study's lead author, Aixue Hu, warned that "major northeastern cities are directly in the path of the greatest rise."

This illustrates the fact that adapting to climate change in specific areas depends on developing a sophisticated knowledge of exactly what will happen in that specific area. You can't just base plans on expected large-scale averages, such as global sea level rise.

At the same time, developing a green energy economy for a specific site will depend on that adaptation. If, for example, sea level rise can be expected to overwhelm today's coastal zone, it would make no sense to develop wind and ocean wave energy installations in that zone.

Changes now underway in sea level, in patterns of drought and precipitation, or in river flow will be different in different areas around the world. Some areas my become unlivable. People may flock to more favored regions. How people adapt to their new situations will determine how they use energy. Successfully adapting to climate change while curbing greenhouse gases depends on site-specific knowledge – knowing what's going on where people live.

Broad-brush planning won't cut it.