Research reveals potential of an overlooked solution to climate change
Earlier this month, President Biden urged other countries to join the US and the European Union to commit to reducing methane emissions. Two new Stanford-led studies could pave the way by creating a blueprint for coordinating research on methane removal technologies and modeling how the approach could have an oversized effect on reducing future peak temperatures.
The analyzes, published in Philosophical Transactions of the Royal Society A, show that eliminating about three years worth of man-made emissions of the strong greenhouse gas would lower global surface temperature by about 0.21 degrees Celsius while lowering ozone levels enough to prevent about 50,000 premature deaths annually. The results open the door to direct comparisons with carbon dioxide removal – an approach that has seen significantly more research and investment – and could help shape national and international climate policy in the future.
“The time has come to invest in methane removal technologies,” said Rob Jackson, lead author of the new research agenda paper and senior writer on modeling Modeling study. Jackson is Michelle and Kevin Douglas Provostial Professor of Energy and Environment at the Stanford School of Earth, Energy & Environmental Sciences.
The case for methane removal
The relative concentration of methane has grown more than twice as fast as that of carbon dioxide since the beginning of the industrial revolution. Removing methane from the atmosphere could lower temperatures even faster than removing carbon dioxide alone, since methane is 81 times more powerful in the first 20 years after its release and about 27 times more effective at warming the climate in a century. The removal of methane also improves air quality by reducing the concentration of tropospheric ozone, which is estimated to cause an estimated 1 million premature deaths from respiratory diseases worldwide each year.
In contrast to carbon dioxide, the majority of methane emissions are caused by humans. The main culprits include agricultural sources such as cattle, which release methane in breath and dung, and rice fields, which release methane when flooded. Waste disposal and the extraction of fossil fuels also contribute to significant emissions. Natural methane sources, including wetland soil microbes, account for the remaining 40 percent of global methane emissions. They further complicate the picture as some of them, like the thawing permafrost, are expected to increase as the planet warms.
While the development of methane removal technologies will not be easy, the potential financial benefits are great. If carbon offsetting market prices rise to $ 100 or more per tonne this century, as predicted by most relevant valuation models, every tonne of methane removed from the atmosphere could be worth more than $ 2,700.
Presentation of the effects of methane removal
The modeling study uses a new model developed by the UK National Weather Service (known as the UK Met Office) to study the potential impact of methane removal, taking into account its shorter lifespan than carbon dioxide – a key factor as part of the removed Methane is gone anyway. The researchers created a number of scenarios, varying either the amount removed or the timing of removal, to generalize their results to a wide range of realistic future emission pathways.
In a scenario with high emissions, the analysis showed that a 40 percent reduction in global methane emissions by 2050 would lead to a temperature reduction of around 0.4 degrees Celsius by 2050. In a low emission scenario where the temperature in the 21st of the same order of magnitude could lower the peak temperature by up to one degree Celsius.
“This new model allows us to better understand how methane removal changes global warming and human-scale air quality,” said Sam Abernethy, lead author of the model study and co-author of the research agenda, a PhD student in applied physics working at Jacksons Laboratory works.
From research to development
The way to achieve these climate and air quality improvements remains unclear. To put this at the center, the Research Agenda paper compares and contrasts aspects of carbon dioxide and methane removal, describes a range of methane removal technologies, and outlines a framework for coordinating and accelerating their scaling. The framework would help facilitate a more in-depth analysis of methane removal factors, ranging from site-specific simulations to potential interactions with other approaches to climate change mitigation.
Methane is difficult to remove from the air due to its low concentration, but emerging technologies – like a class of crystalline materials called zeolites that can soak up the gas – promise researchers a solution. They advocate increased research into the costs, efficiency, scaling and energy requirements of these technologies, potential social barriers to use, additional benefits and possible negative by-products.
“The removal of carbon dioxide has generated billions of dollars in investment, with dozens of companies starting,” Jackson said. “We need similar commitments for methane removal.”
– This press release was originally posted on the Stanford University website