A recent study published in the journal Science highlights a worrying issue: more than half of landfills in the United States are significant sources of methane emissions, a potent greenhouse gas. Conducted by the Carbon Mapper research group, in collaboration with renowned institutions such as NASA Jet Propulsion Laboratory and the University of Arizona, this investigation is the largest assessment of methane emissions from landfills ever carried out to date.
According to the research, around 52% of landfills analyzed through aerial surveys had sources of methane emissions, an alarming contrast with the percentage of 0.2% to 1% identified in super-emission sites in the oil and gas sector, the largest US methane emitter. Identifying these emissions provides an immediate opportunity for mitigation, enhancing climate benefits by addressing one of the most potent and prevalent greenhouse gases.
What are the Implications of Persistent Emissions from Landfills?
According to Dan Cusworth, Carbon Mapper scientist and lead author of the study, 60% of large landfills emit methane persistently, lasting months or even years. This differs substantially from the oil and gas sector, where most emissions from large emitters are short-lived events. This factor highlights the opportunity and need to focus on actions to mitigate ongoing emissions from landfills.
How Can Regulators Act on Methane Emissions from Landfills?
The study points out that, to date, regulators and companies have relied on modeled estimates for emissions from landfills, in addition to surveys using manual methane sensors, which provide a less comprehensive view of reality. However, with the advancement of aerial surveys and the launch of more satellites, it is expected that regulators will be able to measure, quantify and act more effectively on methane emissions from landfills.
How Underestimated Are Methane Emissions According to the Study?
The research revealed that emission rates detected by aerial surveys are 1.4 times higher than estimates from the U.S. Environmental Protection Agency’s (EPA) own greenhouse gas reporting system. This discrepancy highlights the importance of updating and refining monitoring and reporting methods to more accurately reflect the true scale of emissions.
Efforts to combat global warming often focus on reducing carbon dioxide emissions. However, methane, which is about 25 times more powerful at trapping heat in the atmosphere than CO2 over a 100-year period, represents an equally crucial front in the fight against climate change. This study underscores the critical need to expand the regulatory and mitigation focus to include methane emissions, particularly those from landfills, which have thus far been relatively neglected compared to other sectors.
As a society, we face the urgent challenge of addressing climate change with immediate and effective action. The knowledge and technology to identify and mitigate these super methane emitters exists; now is the time to put these tools into practice to protect our planet for future generations.
