Good news. Methane concentration in the atmosphere has not increased during the past 8 years. Methane is estimated to be responsible for 9 to 17% of the global warming caused by human activity. During its total life in the stratosphere, methane does 23 times the heat trapping damage of CO2 over a 100 year period. Fortunately methane released into the atmosphere largely dissipates in about 12 years. CO2 stays as part of the heat trap for about 100 years.
Back in 1860, before we became big users of fossil fuels, methane concentration was 750 ppb. By the year 1998, it was 1,750 ppb, a frightening increase. Since 1998, however, there has been no increase. This represents major progress in the battle to stop global warming. We should celebrate.
The good news was reported by Dr. Sherwood Rowland, who was awarded the Nobel Prize for co-discovering the atmospheric damage caused by another family of greenhouse gases – chlorofluorocarbons (CFC). Dr. Rowland and his team at the University of California at Irvine have been carefully monitoring greenhouse gas concentrations for many years. I had the good fortune of taking chemistry from Dr. Rowland when I was a student at UCI.
The growing atmospheric concentration of CFC was the result of using the chemicals in refrigerants, hairspray and more. A life threatening hole in the ozone was developing. The ozone layer protects us from getting zapped and fried by gamma rays, x-rays, and ultraviolet rays. This ozone shield was saved thanks to the brilliant work of Nobel Prize chemists Dr. Sherwood Rowland, Dr. Mario Molina, and Dr. Paul Crutzen.
Although the news is good about reducing emissions of methane and CFC, CO2 concentration continues to increase at a rate which threatens our future. What works? What needs to be done?
Methane concentration may have stopped growing because natural gas prices have skyrocketed, and natural gas is typically 90% methane. Natural gas is often a byproduct of oil drilling. When natural gas was cheap, oil producers let it vent into the atmosphere. As more power plants have used natural gas, its price has increased. In 1946, natural gas cost only 5 cents per thousand cubic feet. By 2000, $3.68. Now it makes money to capture it and sell it, or produce energy on the spot. (EIA Data)
Landfills are the #1 emitter of methane in the USA. The city of Burbank formerly let landfill gas go into the atmosphere. Now it pipes the gas into 11 microturbines that generate 550kW of electricity. The city estimates that it achieves a 100% return on investment annually. As committed to in the City’s Renewable Portfolio Standard, 20% of the power used by Burbank’s residents and businesses will come from renewable sources by 2017.
Major emitters of methane include the oil and gas industry, the coal industry, and landfills. All now have the technology and market incentives to capture natural gas for power and fuel. Another major source of methane is cattle ranching. If methane emissions were priced into beef, we would be less likely to say “supersize me.” Ranchers would raise more wind towers and less cattle.
CO2 emissions must be brought under control. Because CO2 has an average atmospheric lifetime of 100 years, it is accumulating at a dangerous rate. From a preindustrial concentration of 280 ppm, it now nears 400 ppm. Business as usual, in our lifetime, could take it to 600 ppm. This growth creates the risk of runaway effects. For example, should the ice melt on large land bodies now covered with ice, there could be huge methane releases. Another runaway danger is if tropical forests and oceans stop absorbing CO2.
The fastest way to reduce our CO2 emission is to reduce our use of coal and oil. With coal, it is a double bonus because reducing coal mining also reduces methane emissions. Coal is used to feed power plants. Most of the energy input from coal is lost through inefficient power plants and inefficient use of energy in homes and industry. Energy efficiency and renewable alternatives are the best ways to reduce coal usage. Oil reduction can be achieved if we spend more time riding together, riding less and riding clean.
Yes, we can reduce greenhouse gas emissions. CFC concentrations are starting to decline because on September 16, 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer was signed into agreement by the major countries of the world (originally 24 countries, now 175). A process for all nations to phase-out production of dangerous CFCs and halons was established. Later, other dangerous chemicals were added to the list. Now, the phase-out is largely complete.
International treaties work. Market mechanisms work. International treaties that include market mechanisms for trading greenhouse gas emissions work great. A new treaty with binding targets and pricing mechanisms is needed. It is time for the world’s biggest emitters, the USA and China, to lead the process to a health future and away from a reckless joy ride towards climate chaos.