NEW research has shown that natural methane emissions from melting permafrost in Arctic regions and from tropical wetlands, are much higher than previously thought and increasing, a consequence of overall warmer atmospheric temperatures induced by human activity. The phenomenon has been long feared by climate scientists and now appears to be a reality: It is called the “clathrate gun,” a feedback loop in which a warmer atmosphere causes methane to be released, which in turn causes more atmospheric warming, releasing more methane. There is nothing that can be done about it directly, but the phenomenon and its consequences make the reduction of all manner of man-made emissions an even more critical priority.
Methane, which has the chemical symbol CH4, is a potent greenhouse gas (GHG) that traps heat in the atmosphere about 80 times more effectively than carbon dioxide (CO2). CO2 emissions are given more attention because they are released into the atmosphere in much greater volumes, and CO2 can remain in the atmosphere for centuries, whereas methane is broken down in about 20 years. During that time, however, it can sharply accelerate global warming. And, of course, if more methane is continuously added to the atmosphere, the length of time it is a problem will be continuously extended.
About 60 percent of methane emissions are from fossil fuel use, farming, landfills and waste, with the rest coming from rotting vegetation in wetlands in the tropics and Northern Hemisphere. A great deal of methane is locked up in permafrost, the permanently frozen soil in the vast Arctic regions of Siberia and North America, as well as on the seabed in ice formations called clathrates, where the methane gas is trapped within the crystalline structure of the ice. As the permafrost and the deep-sea ice melts due to global warming, the trapped methane is released.
Just how much is being released, and how fast were the questions the recent research from Duke University’s Nicolas School of the Environment intended to discover? Unfortunately, the answers to those questions were “a lot” and “very quickly.” The biggest trouble spot is in the Arctic, where the scientists measured high methane emissions during the summer, which was anticipated, but also during the winter and from so-called dry permafrost, permafrost where the surface has not yet melted. The researchers also discovered that the rate of methane emissions had increased in tropical wetlands, which have become warmer and wetter and have expanded over the past 20 years, another consequence that scientists believe can be attributed to global warming.
The researchers concluded that at the current rate of methane emissions, even taking into consideration efforts toward methane reduction from human sources that are already taking place, there is absolutely no chance that the 2021 pledge by more than 100 nations to cut methane emissions from anthropogenic sources 30 percent by 2030 would have any significant impact on methane concentrations in the atmosphere, or on the rate of global warming.
Human and man-made sources
Again, there is nothing that people can do about natural sources of methane, but what can be done is to ramp up efforts to cut the 60 percent of atmospheric methane that comes from human sources. The two biggest sources of man-made methane emissions are the oil and gas industry and agriculture, followed by landfills. Reducing methane emissions from agriculture is difficult, said the research’s lead author, “Cutting emissions from agriculture in particular is improbable in the near-term, and maybe even in the long term.” Cutting emissions from other sources, however, is within reach.
Here in the Philippines, we have recently embarked on a large-scale effort to expand natural gas infrastructure for the purpose of electricity generation. There are also 290 sanitary landfills in the country, as well as an unknown number of informal dump sites. Those are all things that we can address with methane emissions control measures, and the government should hasten to study and implement the proper regulations. The usual excuse for not doing so, that the Philippines is only a small contributor to overall global emissions and suffers more ill effects from climate change than it causes, is immaterial. Minor contributor to GHG emissions or not, we should still do everything we can to contribute to a global solution.