A lot has happened since the last Intergovernmental Panel on Climate Change (IPCC) Synthesis Report was published in 2014. Historically, the majority of climate change mitigation has been focused on reducing emissions of CO2, but beginning in 2021, the IPCC shifted its focus to the highest near-term priority: reducing methane emissions.
In fact, in its latest report, the IPPC stated, “More rapid reduction in CO2 and non-CO2 emissions, particularly methane, limits peak warming levels and reduces the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility and sustainability concerns, and social and environmental risks.”
Calls for adaptation, mitigation, and overall action have increased, with “evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, … further strengthened since AR5” (IPCC AR6). These adverse impacts have shown that global action is more crucial than previously thought, even when compared to 2014’s AR5 findings.
Near-Term Impact of GHG Emissions Reduction
While the need for action has grown, so too have the policies and laws that support and address greenhouse gas emissions. Global warming and observed warming from GHGs is primarily due to carbon dioxide (CO2) and methane (CH4). Previously garnering less of a focus than carbon dioxide, methane shows 28-34 times the global warming potential of C02 on a 100-year timescale (GWP100, per IPCC AR5) — 84-86 times more potent than CO2 on a 20-year timescale, according to the United Nations Economic Commission for Europe.
By rapidly reducing methane emissions, we can improve air quality and related health concerns “in the near term” — noted in the AR6 as by 2040 — since methane emissions in particular create more surface ozone.
According to the report, targeting methane emissions reduction from coal mining, oil and gas, and landfills can have a large impact on today’s crucial climate initiatives. In fact, landfills are highly concentrated sources of methane emissions, and a key place to start when targeting emissions reduction. By leveraging new technology and best practices at landfills, we can reduce those emissions on a large scale and at a comparably low cost. In 2019 alone, the recorded concentrations of methane in the atmosphere were higher than at any time in at least 800,000 years. With findings like that, it’s no surprise that extreme weather conditions — and our observed impact — have continued to increase since the AR5.
What Are the Long-Term Ramifications of Rising Global Temperatures?
While we focus on mitigating GHG emissions in the short term, the long-term ramifications are also becoming more apparent, as evidenced by the figure below from the newest IPCC report:
The extent to which current and future generations will experience a hotter and different
world depends on choices now and in the near-term
Figure Caption: Changes in annual global surface temperatures are presented as ‘climate stripes’, with future projections showing the human-caused long-term trends and continuing modulation by natural variability (represented here using observed levels of past natural variability). Colours on the generational icons correspond to the global surface temperature stripes for each year, with segments on future icons differentiating possible future experiences. Source: IPCC AR6
What’s Next in Minimizing Emissions?
Focusing on policies and practices that create rapid and sustainable reductions in methane emissions would lead to a “discernible slowdown in global warming within around two decades, and also to discernible changes in atmospheric composition within a few years.” And yet, the projected time at which we’ll likely reach 1.5°C in global warming will still fall within the “near term” — before 2040.
Yes, certain negative environmental changes due to global warming may be both unavoidable and irreversible, but that doesn’t mean we can’t mitigate that impact. Getting on the path to a tangible positive impact requires significant emissions reduction, including methane.
Figure Caption: Global emissions pathways consistent with implemented policies and mitigation strategies. Panel (c) shows the development of global methane emissions in modelled pathways. Source: IPCC AR6
A total of 150 countries have signed the Global Methane Pledge that launched in November 2021, coming together to act. Pledge participants are taking voluntary steps to reduce global methane emissions “at least 30 percent from 2020 levels by 2030, which could eliminate over 0.2˚C warming by 2050.”
With inherent urgency and these findings now more readily available to policymakers, the next step is to acknowledge and act on the need for greater investments — costs which can be decreased by supportive policies. According to the report, “Policy packages tailored to national contexts and technological characteristics have been effective in supporting low-emission innovation and technology diffusion.”
Armed with that knowledge, we can leverage new policies to support and contribute to curbing methane emissions. By using resources that are both readily available and new data and technologies that are backed by evolving environmental policies, we can work toward setting up future generations with an environmentally stronger world.