May. 7, 2017

Melting permafrost

I know the focus in climate change greenhouse gases is carbon dioxide. Humans produce an enormous amount of CO2 by burning fossil fuels for energy production, which accounts for 82% of anthropogenic greenhouse gases. Last year people produced 38.2 BILLION tons of it. But I want to focus on another greenhouse gas, methane or what is often called natural gas. It is often ignored because it is released in much smaller amounts than CO2, but methane is 84 times more potent than CO2 in absorbing heat energy (over 2 decades because it doesn’t last as long in the atmosphere than CO2). Currently methane only accounts for 9% of man-made greenhouse gases, but it does contain carbon which is the element that is responsible for trapping infrared or heat energy in the atmosphere (CH4).  

The main natural sources of methane include wetlands, termites and the oceans. Natural sources create 36% of methane emissions. But since the Industrial Revolution, human sources of methane emissions have been growing. Fossil fuel production and intensive livestock farming have caused the current increase methane levels. Together these two sources are responsible for 60% of all human methane emissions. Methane is released during mining and extraction of coal and oil. Incomplete combustion of fossil fuels also produces methane emissions. No combustion process is one hundred percent efficient. So when fossil fuels get used to make electricity, heat or power cars these all produce methane. Nearly a third of methane emissions come from domestic animals, especially beef. Livestock farming creates 90 million tons of methane per year. Methane gets generated by the decomposition of solid waste in landfills accounting for 16% of human contribution to methane in the atmosphere. Other sources include landfills and waste (16%), biomass burning (11%), rice agriculture (9%) as well as biofuels (4%).

But, I am worried about the methane that is released when permafrost melts. As permafrost soil thaws, the organic matter is decomposed by microbes releasing methane in the process. The higher latitudes, where permafrost soil is prevalent, seem to be more sensitive and vulnerable to changes in the climate than the mid-latitudes or equatorial regions. This is called polar amplification. As the ice melts, the darker soils beneath absorb rather than reflect sunlight. The Arctic is changing rapidly, geologically speaking, and methane emissions released by thawing permafrost could significantly affect levels of greenhouse gases in the atmosphere. Not only are these frozen reservoirs thawing out more extensively than previously thought, but at this stage, there’s little that can be done about it. Many researchers are concerned that if old carbon begins to cycle it could create a feedback loop—its emissions contribute to warming, which again contributes to the thawing of more permafrost (which adds more carbon to the atmosphere, adding to the warming). Once it reaches a tipping point, major changes in climate may be impossible to prevent.

An emerging consensus among Artic scientists, based on continuing fieldwork, reveals a real danger of unprecedented quantities of methane venting due to thawing permafrost. A 2010 analysis of 20 field expeditions in Review of Geophysics recognized the plausibility of catastrophic methane releases from Artic permafrost. It is estimated that 70 billion tons of methane is stored just in Siberian permafrost. If it melts it will be equivalent to emitting 1.7 trillion tons of CO2 which is more greenhouse gas than has been emitted by humans in the past 200 years. This scenario has been dubbed a climate time bomb because of the danger of a rapid release. In 2008, The U.S. Department of Energy National Laboratory identified the destabilization in the Arctic as one of the most serious scenarios for abrupt climate change.

As I mentioned in the post on The Great Dying, methane is associated with a major extinction event at the end of the Permian when 90% of the earth’s species became extinct. Although there is consensus among scientists that study the Arctic, there is still debate about the methane time bomb among others, especially climate change denier think tanks that pick at others research, but do not actually conduct research of their own.

And the crazy thing is, the best solution to anthropogenic climate change is sustainable energy. Energy that would benefit people in so many ways: lower electric bills (in the long-term), energy self-reliance, localization of energy production, and lower greenhouse gas emissions. A full win-win situation. Unfortunately, with our current political polarization, politically we seem to think in terms of win-lose rather than win-win. But we have to consider what we will lose in this battel of political wills. If there is even a chance of abrupt methane release, it will change the world as we know it- it will be catastrophic. I hate to harp on this gloom and doom message, but, as my partner likes to say, “It is what it is.” And it is the greatest fear I have for the world we will be leaving my grandchildren, nieces and nephews and yours as well.