It seems like methane has become the hot new topic in climate change discussions (no pun intended). So what is methane, and why are we hearing so much about it these days?
What is methane?
Like the better-known carbon dioxide (CO2), methane is a greenhouse gas (GHG). This means that, like a greenhouse, methane traps heat and keeps it in our atmosphere rather than letting it escape, leading to an overall rise in temperatures. CO2 is more plentiful than methane¬, but it is much less effective at retaining heat. If methane is a greenhouse with glass windows, CO2 is a gazebo screened with linen curtains.
It gets trickier when it comes to calculating the total impact of each gas on the climate, however. Although methane packs more of a punch than CO2, it only stays in the atmosphere for about 12 years, while the CO2 sticks around for much longer. This means that comparing the global warming potential (GWP) of the two GHGs depends on the timeframe.
If we take a long view and consider the impact over the next century—known as the 100-year GWP or GWP100—the methane will only exist for a short portion of that window, so its warming impact, averaged out over time, will be relatively low. According to the latest report from the Intergovernmental Panel on Climate Change (IPCC), released in August, methane has nearly 30 times the impact of CO2. However, with a shorter timeframe—most commonly 20 years (GWP20)—the effect of the methane is much more concentrated. The IPCC calculates that a molecule of methane released in 2021 will contribute more than 80 times as much to warming in 2041 as a molecule of CO2. Readers will often see this relationship expressed in CO2 equivalency: one ton of methane is equivalent to 80+ tons of CO2 (tons CO2eq) using the GWP20 metric.
Where does methane come from?
Methane is generated by many sources. The anthropogenic sources (meaning those caused by humans) are often natural processes that have been intensified by human activities. For example, animals like cows produce methane through digestion. While this would happen with or without human involvement, our animal agriculture practices mean that there are many more cows than there would be naturally, and therefore much more methane. Likewise, rotting plant matter emits methane in the absence of oxygen. This can occur in peat bogs and other natural environments, but it happens on a much grander scale when we dump food waste in landfills. Waste, agriculture, and the fossil fuel industry are responsible for most anthropogenic methane emissions.
Why are there so many articles about methane lately?
As it has become clearer than ever that we are in a race to halt our emissions before climate change spirals out of control, scientists are focusing more and more on the immediate impact we can make by reducing methane emissions.
It’s not news that methane is a problem. Rather, if methane is more publicized today, it’s because we’re coming up against a tight deadline for climate action at the same time as our ability to quantify the size and severity of the methane problem is improving. Satellite technology now allows us to measure the methane in the atmosphere—and even pinpoint the sources—rather than calculate the amount we think is being released using models and formulas. Meanwhile, advanced climate simulations have shown that, to reach our target of limiting warming to 1.5°C above pre-industrial temperatures, we need to reduce our emissions of methane as well as CO2.
Drew Shindell, an earth science professor at Duke University, is one of the scientists calling for increased attention to this problem—and, importantly, to existing solutions. Shindell served as chair for the Global Methane Assessment, released in May 2021 by the United Nations Environment Programme and the Climate & Clean Air Coalition. One of the assessment’s major findings is that we could cut methane emissions by 45% using methods and technology we already have. What’s more, more than half of these measures can be achieved either at low cost or with cost savings.
UBQ’s novel technology allows us to address these same goals—reducing methane emissions in the waste sector, right when we need it the most. And with the creation of the Global Methane Pledge, we are more optimistic than ever that humanity can avoid catastrophic climate change through collective action and technological innovation.