Natural gas, whose principal constituent is methane, is touted as a "bridge fuel" to be used in a transition from fossil fuels, notably coal, to renewable, sustainable sources of energy. Switching would theoretically combat global warming by decreasing carbon dioxide emissions. It is not that simple. Ignoring, for the moment, the fact that air pollution deaths and disease produced by burning gas are substantially less than the morbidity caused by burning coal, let us focus on climate change and methane.
Climate change is arguably the most important public health problem faced by everyone on earth. A partial glimpse into the future demonstrates why the stakes are so high. The EPA already lists heat as the most important weather-related cause of death. It is axiomatic to conclude that as the earth warms, the number of heat-related deaths will increase. These deaths are clustered at the times of heat waves. In July, 1993, 118 heat related deaths occurred in Philadelphia and in 1995, 7,000 occurred in Chicago. These numbers are dwarfed by the 70,000 European deaths in the 2003 heat wave. Heat, drought, and crop failure go together. In July 2012 the U.S. heat wave and drought led to a 10 percent increase in world food prices posing additional threats to countries where childhood malnutrition was already nearly 50 percent. Since 1980, climate-related reductions in maize production in China and Brazil, wheat production in Russia, and soy production in Paraguay have made it increasingly difficult to feed everyone. Rising sea levels will create millions of refugees among those living in river deltas. Drastic alterations in the patterns of infectious diseases are likely. We can expect large changes in regions where malaria is endemic, expanding in India and Africa and retreating elsewhere. This disease caused about 1.2 million deaths in 2010, more than twice as many as previously estimated. Dengue, or "breakbone fever," infects about 390 million people per year. By 2085, as many as 5-6 billion people will be at risk for contracting this disease. As a final example, the unprecedented 2010 upsurge in the number of West Nile virus cases in Europe and the 2012 surge in the U.S. were attributed to unusual warming. Social well-being is an element of health. Thus the 2013 report linking interpersonal and intergroup violence with temperature and rainfall increases provides another dimension to health on a hotter planet.
This picture of the future, marked by more extreme heat events, more severe weather, failing crops, widespread malnutrition, and rampant infectious diseases, and marred by higher levels of violence could be bleak unless we take action. This 'biopsy" of studies linking health with climate change illustrates the critical importance of minimizing future increases in global temperatures. To do this, we must limit emissions of greenhouse gases, taking us back to the question, is methane a suitable bridge fuel?
Methane is touted as a cleaner fuel because it produces less carbon dioxide than coal when burned. This apparent advantage wanes and may even disappear when long-term effects of the complete life-cycle of coal and methane are examined. Methane is the second most important greenhouse gas. However the climate change potential of methane is between 25 and 72 times greater than that of carbon dioxide, depending when after emission the ratio is measured.
The EPA estimates that 30 percent of U.S. methane emissions arise from the natural gas and petroleum industries.. A Cornell study showed that this may be a serious underestimate. This research showed that methane emissions during hydraulic fracturing were between 30-100 percent greater than emissions during conventional gas production. Emissions were estimated to be between 3.6 percent and 7.9 percent of the total amount extracted. Because of the high climate change potency of methane, they concluded that the 20 year warming effect of hydrofracked gas was 20-100 percent greater than that of coal. Not surprisingly, their results were challenged in a critique by the American Gas Alliance but refuted by the investigators. Recent university and NOAA-sponsored airborne methane measurements made over a gas field in Utah showed that between 6.2 and 11.7 percent of the hourly production escaped into the atmosphere. This estimate buttresses the original Cornell conclusion. Substantial amounts of natural gas are released from pipelines. Vehicles equipped with methane detectors cruised the streets of Boston and found 3,356 leaks with some air concentrations reaching 28.6 ppm, over 15 times greater than the global average. Methane is a gas to be taken seriously, but are we up to the task?
From a climate change perspective, it may not make any difference if natural gas is somewhat better or worse than coal. Both are serious threats to the earth's energy balance. Burning any fossil fuel is not a satisfactory long-term solution to our energy needs. We are at the edge of a climate precipice and we are badly in need of a bridge to a renewable energy future. Wind, water, and sunlight (WWS) combined with improved energy efficiency may the solution, given a chance. A plan to supply virtually all of New York State's energy needs by 2030 using these three sources deserves more careful scrutiny. Some of that WWS energy would be used to split water into oxygen and hydrogen. Reservoirs of stored hydrogen and expanded use of fuel cells would power the economy when other sources were insufficient. We need better ways to harness the enormous amount of solar energy that reaches the earth each day. To move beyond the WWS strategy envisioned in the New York plan we need to support research and the education system that makes research possible. Artificial photosynthesis and using sunlight to split water molecules into their hydrogen and oxygen components (photocatalytic splitting) are technologies that exist in today's laboratories and have the potential to be reproduced on a scale that could lead to true energy independence and a sustainable energy future.
This what I believe President Obama was asking us to do when he called on us realize the huge American potential to "out-innovate, out-educate, and out-build" the rest of the world in his January 25, 2011 State of the Union Speech. Are we able to build a bridge to the future or will we build a bridge to nowhere?