Are current climate change mitigation efforts enough? The truth is that up to now, emissions reduction technologies have focused on CO2, neglecting methane – another culprit of climate change. The second most important greenhouse gas after CO2, methane has been steadily increasing in recent years and has contributed around 0.5 ℃ to global warming since 2010. This makes one thing clear: the battle against climate change needs a variety of technologies and approaches to succeed, and methane removal could play an important role in these efforts. A new modelling study supported in part by the EU-funded CRESCENDO project has now explored how removing methane from the atmosphere can improve air quality and reduce temperatures. The research findings have been published in the journal ‘Philosophical Transactions of the Royal Society A’.
Less methane equals lower temperatures and ozone levels
Global methane emissions are estimated to total about 570 million tonnes, or 0.57 gigatonnes per year. This potent greenhouse gas directly affects air quality by increasing the concentration of ground-level ozone. Exposure to ozone is believed to cause around 1 million premature deaths worldwide as a result of respiratory illnesses. According to the study, removing 1 gigatonne of methane will reduce global surface temperatures by about 0.21 ℃ and surface ozone levels by about 1 part per billion – enough to prevent 50 000 premature deaths per year across the globe. Additionally, reduced ozone levels improve vegetation and crop yields – an added benefit of methane removal. These results indicate that removing methane from the atmosphere could complement current CO2 emissions reduction efforts to meet the Paris Agreement climate goals. “The time is ripe to invest in methane removal technologies,” remarks the study’s senior author Prof. Rob Jackson of Stanford University, United States, in a news item posted on ‘SciTechDaily’. For the modelling study, the research team used a new methane emissions-driven Earth System Model developed by the United Kingdom’s national weather service, CRESCENDO project partner Met Office. They used this model to simulate the impact of methane removal on climate and air quality, creating a set of scenarios by varying the rate and timing of removal. The team’s simulations showed that a 40 % reduction in methane emissions by 2050 will lead to an approximate 0.4 ℃ drop in global temperatures in the same period of time. “This new model allows us to better understand how methane removal alters warming on the global scale and air quality on the human scale,” notes study lead author Sam Abernethy, a PhD student in atmospheric modelling at Stanford University. CRESCENDO (Coordinated Research in Earth Systems and Climate: Experiments, kNowledge, Dissemination and Outreach) was coordinated by the University of Leeds, United Kingdom. The project ended in March 2021. For more information, please see: CRESCENDO project website
CRESCENDO, methane, CO2, climate, ozone, emissions, methane removal, air quality, temperature