September 23, 2024 by European Commission, Joint Research Centre (JRC)
Collected at: https://phys.org/news/2024-09-methane-emissions-key-climate-ozone.html
Many human activities lead to methane being released into the atmosphere. Agriculture, landfills, wastewater, and fossil fuel production and distribution are the biggest contributors. These make up roughly 60% of global methane emissions, and natural sources account for the remaining 40% of emissions.
Like carbon dioxide (CO2), methane is a potent greenhouse gas, estimated to be responsible for more than 40% of recent global warming. However, methane has an atmospheric lifespan (the time it takes to breakdown into something else) of only about 12 years, much shorter than CO2.
This means that cutting methane emissions can have a quicker response than CO2 on slowing global temperature rise.
Methane also contributes to ground-level (tropospheric) ozone, a dangerous air pollutant. Many people know that the ozone layer in the upper atmosphere helps protect us from harmful ultraviolet rays from the sun, and efforts have been made to protect the ozone layer after decades of decline.
However, ozone released at ground level can be very harmful because it reacts aggressively with lung tissue, causing respiratory illnesses in humans as well as damaging crops and natural vegetation. Recent estimates suggest that roughly 1 million people die prematurely every year because of exposure to harmful tropospheric ozone, 24,000 of those in the EU.
A new JRC paper has studied these effects and highlights how strengthened international cooperation through the Global Methane Pledge can help cut climate-warming, improve human health and improve crop yields—if we act fast.
Methane’s impact on ozone
While the natural background (not due to human activity) is the largest contributor to ozone levels, the study finds that methane is responsible for 35% of global harmful ozone and roughly 37% in the EU. Globally, it is projected that ozone-related mortalities due to methane emissions will increase by at least 7% by 2050 compared with 2015, even under the strictest reduction scenarios.
Reducing methane emissions also helps reduce crop damage from ozone. The study estimates that if we continue with high methane emissions, by 2050 we could see losses in crop yield costing anywhere between USD $404–566 million. Whereas, taking strong actions leading to a “high mitigation scenario” could significantly reduce these losses with savings worth USD $39–48 million in Europe alone.
International commitments
The Global Methane Pledge, launched at COP26 by the European Union and the United States, is a collective voluntary commitment to reduce global anthropogenic methane emissions by at least 30% below 2020 levels by 2030. 158 countries as well as the European Union are now participating in the pledge.
In 2020, the EU adopted the Methane Strategy, a comprehensive plan to reduce methane emissions. The strategy focuses on EU and international actions, particularly in the energy, agricultural, waste, and wastewater sectors. A new EU regulation was agreed the following year to reduce methane emissions from the energy sector, both within Europe and its global supply chains.
Positive impact on society
European policy makers and national governments need reliable scientific evidence to help inform their decisions. The importance of cutting methane emissions has been known for a long time, but understanding the costs of inaction, and how significant the benefits of actions are in the short term is vital.
This research helps to show that by cutting methane emissions today, we can fight climate change, strengthen our economy, and improve human health, taking pressure off over-stretched health care systems and helping citizens live better lives.
More information: Trends of methane emissions and their impact on ozone concentrations at the European and global levels. op.europa.eu/publication/manif … ier/PUB_KJNA32005ENN
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