Dr. Bill Chameides is the dean of Duke University's Nicholas School of the Environment and a member of the National Academy of Sciences. He blogs regularly at theGreenGrok.com. Follow him on Twitter: theGreenGrok
I just returned from the 2-day climate summit at the National Academies sponsored by our America"s Climate Choices study. Here are some of the take-away messages.
Huge Technological and Lifestyle Challenge
"The emissions of the future rich must eventually equal the emissions of today's poor."-- Rob Socolow, Professor of Mechanical and Aerospace Engineering, Princeton University
Right now, each year, the average American is responsible for about 20 tons of direct emissions of carbon dioxide (CO2), the chief global warming gas. The average non-American emits about three tons per year. An average Pakistani is responsible for about one ton per year, and average folks from the poorest of countries like Bangladesh fall well below one ton.
To meet emission targets to avoid dangerous anthropogenic interference in the climate, the average annual emissions for each person in the entire world will have to fall to about one ton by the end of the century. That's a huge change for Americans. Accomplishing that while maintaining our standard of living is a daunting challenge.
Huge Policy Challenge
"The U.S. is the Saudi Arabia of coal and unconventional oil."-- James Mulva, CEO, ConocoPhillips
Should we choose to do so, we could easily increase instead of decrease our CO2 emissions.
International Policy Will Be Key
"Binding targets for the developing nations is out of the question."
"Without emission policies in the BRIC nations (Brazil, Russia, India, and China), it will be impossible to keep the CO2 concentration below 650 [parts per million]."
(Note that many scientists believe that CO2 concentrations must be held at or below 450 ppm.)
"How we [Americans] move [on climate] will determine the international direction. To lead, we must act."-- Eileen Claussen, Pew Center
Addressing the problem of climate change requires virtually all nations to curb their greenhouse gas emissions, but international action is unlikely without U.S. action. Yet, for many U.S. lawmakers, international commitments are essential before the United States acts.
Adaptation Is Key
Whatever we do now will have little impact on the climate for the next two to three decades; because of the inertia of the climate system, the climate changes of the next 20 to 30 years are already in the "pipeline."
However, what we do now will have a major impact on the kind of world our heirs find at the end of the century. It is therefore essential that in addition to emissions reductions we make adaptation a high priority. Planning now is critical, but the institutional tools for adaptation have yet to be developed.
Watch Out for Climate Extremes
"We need to move [our focus] from the mean to the extremes."
We have already seen a significant increase in heavy downpours in large regions of the United States, especially in the Northeast. (paraphrased)
The real danger of climate change is not that mean temperatures will increase by a few degrees or that average rainfall may increase or decrease a bit. Global warming is really about climate disruption, which will mean an increase in the severity and frequency of extreme events like heat waves, downpours (and thus floods), and droughts. Extreme events are hard to predict and difficult to plan for.
The Economy: The Double- or Triple-Edged Sword?
The economic downturn makes passing climate legislation more difficult (because burning fossil fuels would become more costly). However, some have argued that a robust climate law could actually spark the economy by creating new jobs.
On the other hand the economic downturn will undoubtedly slow the rate of increase in global emissions of CO2 and possibly lead to a modest decrease in them. This will buy us some more time to get the appropriate policies in place to put a brake on CO2 emissions over the long term.
On the other, other hand, if we don't act now, it will be that much more difficult to catch up once the economy gets going again.
By the way, the same holds true if the current quiescence in solar activity should continue for a number of years. It also will slow the warming. But if we use that as an excuse not to act or to delay action, such a choice will hurt when the sun comes back.
A Major Advantage: Long-Time Horizon
Perhaps the best thing we have going for us is the long-time horizon we have to get the job done. If we start lowering greenhouse gas emissions soon, we'll be able to make small reductions (of a percent or so each year) over the rest of the century. The reductions we make in the short-term can be the so-called low hanging fruit - taking advantage of what we already know how to do like increasing efficiency, using more renewables.
The reductions we make further down the road will require new, innovative technologies. Will we be able to develop them? Obviously, we cannot know for sure. But if we consider how much the world has changed technologically over the past 50 and 100 years, it's not hard to imagine that we will be successful. The trick is to put policies in place today that encourage the development of tomorrow's low-carbon technologies.