Sunday, May 29, 2011

What About Global Warming and Tornadoes?

There has been recent discussion about a possible link between the recent rash of mid-west tornadoes and global warming. Bill McKibben implies a link in his 5/23/11 Opinion Piece in the Washington Post. Discussion of this assertion is warranted.

In 2010, John Holdren, President Obama's Assistant for Science and Technology, and Director of the White House Office of Science and Technology Policy, spoke at Berkeley on Science and Technology for Sustainable Well-Being. He points out that the phenomena called Global Warming is well established (although, as any scientific hypothesis, subject to potential overturn through further investigation, but this is very unlikely for a phenomena as widely documented and successfully modeled as global warming).

The increased energy density of a warmer atmosphere is predicted by extensive numerical models to lead to intensified droughts and storms. Holdren suggests that rather than Global Warming, we should call this phenomena Global Climate Disruption.

Modeling indicates that the frequency of tornadoes is not expected to increase - while enhanced temperature of  warm and humid air masses colliding with cold air masses makes tornadoes more likely, a decrease in atmospheric shear with increased global temperature is expected to counteract an increase in tornado frequency. However, an increase in the intensity of tornadoes that do form may be a  result of global warming, and may be evident in the EF5 tornadoes that have recently ravished Tuscaloosa Alabama and Joplin Missouri (although I would suggest that more modeling would be appropriate before possibly stating this more strongly).

Even though we cannot be 100% confident of anthropogenic global warming, and consequent global climate disruption, I believe we should move very aggressively toward implementing policy (e.g., a carbon tax and rebate) and technology (e.g., solar power, and sequestration of carbon dioxide in building materials) to reduce atmospheric carbon dioxide content to 350 parts per million - see James Hansen's 2008 paper on why this limit is expected to be required to avoid a potential disaster for humanity.

Holdren suggests that policy makers should not ignore global warming - thus betting with the public's welfare against unfavorable odds. I agree. As McKibben, I find reprehensible the vote this spring by the U.S. House of Representatives (240 to 184)  to defeat a resolution saying that “climate change is occurring, is caused largely by human activities, and poses significant risks for public health and welfare.”

I suggest that McKibben's assertion of a link between global warming and the damage to Joplin and Tuscaloosa should not be casually dismissed.

Wednesday, May 25, 2011

Reflections on the Fukushima Daiichi Accident

The generation of electrical power with nuclear power is controversial - with positive attributes (no direct CO2 emissions, and a relatively good safety record - fewer attributable deaths per kilowatt-hour than coal), and negative attributes (large potential damage per accident, e.g., Chernobyl & Fukushima, and production of radio-active and fissionable waste).

Clearly we must reduce the risk of nuclear accident through more thoughtful nuclear plant design and careful operation if we are to go forward with the generation of electrical power with nuclear plants. In retrospect, the  design elements are clear that would have prevented the hydrogen explosions and release of radio-active isotopes at the Fukushima Daiichi nuclear plant  following the massive tsunami wave inundation there on 3/11/11.

Used fuel rods should have been stored away from the reactors - with those sufficiently cool (out of service at least 5 years) in dry casks. A garden hose size supply of water could have indefinitely keep the rest from melting.

There should have been provision for an electrical connection of portable generators (supplying very modest amounts of power) to indefinitely extend the emergency batteries that held valves open to allow steam powered turbines to circulate cooling water in the reactor cores as they cooled following the successful deactivation of the fission reactions.

The reaction to Fukushima Daiichi appears to be a flight from nuclear power. I suggest that rather than reacting emotionally to this accident, we give serious thought to our future course. If we are to abandon nuclear power, let us follow a reasoned process.

On 5/10/11, Japanese Prime Minister Kan announced that his country would abandon their plans to build 14 additional nuclear power plants to generate 50% of their electricity with nuclear power by 2030. Kan specified that they will turn instead largely to renewables and conservation.

If this does not meet demand, it is likely that the Japanese will also utilize natural gas to generate electrical power (with demand for it easing with the advent of shale gas production). This will be a setback for CO2 emission mitigation - at least in the near term. But it may turn out that in the longer term  CO2 emissions will be reduced because of Japanese development of renewable energy technology and conservation practice).

A similar flight from nuclear power is underway in Germany. They should be careful about thus creating electrical power shortages in the near term, but this also has potential to further the critical need to mitigate CO2 emission in the longer term through the promotion of the development and deployment of renewable energy technology.

Perhaps in a million years, humanity will look back on the Fukushima Daiichi accident as a turning point in our use of technology - the moment when humanity truly realized that technology choices have consequences, and that our choices need to better reflect consideration of our descendents as well as the other species with whom we share the Earth.