The Urgent Need to Cut Super Climate Pollutants Now!

I was privileged to work on climate change issues in the World Bank Group for 16 years, from 1997 to 2014.  Since I retired, climate change has become a critical development challenge and a major consideration for WBG country strategies and project investments. While the issue has become a high priority for the WBG, identifying and implementing the necessary solutions remains very much a work in progress.

With two climate experts, Stephen O. Andersen and Durwood Zaelke, I co-authored the book Cut Super Climate Pollutants Now!, in April last year.  In 78 short pages (with many supporting references), we explain the urgent need to reduce emissions of four sources of global warming in addition to carbon dioxide (CO2) from fossil fuel combustion.  These four “super pollutants,” methane (natural gas), HFCs (chemicals widely used in air conditioning and refrigeration), black carbon (soot), and tropospheric ozone are much more potent sources of warming than CO2.  When compared over 20 years, for example, the warming impact of methane is more than 80 times greater than CO2.  However, because they have much shorter lifetimes in the atmosphere these four pollutants can be reduced much more quickly, mitigating warming in as soon as about a decade.

In contrast reducing carbon emissions will do little to slow warming for the next two or three decades. Up to 40% of the CO2 in the atmosphere will remain for 500 years or more, meaning reductions in emissions have a very gradual impact on atmospheric concentrations. It’s a lot like slowly letting water out of a very full bathtub while the tap continues to run — the water level declines only gradually, if at all. This short-term challenge is made even more difficult because reducing coal combustion will also reduce release of sulfates, pollutants that fall out of the air in days but reflect solar radiation and thus provide some offsetting cooling. Reducing the short-lived warming agents we termed the “climate sprint,” while the much slower measures necessary to eliminate CO2 emissions from fossil fuels constitute the “climate marathon”.  Both are essential.

Our book describes many practical measures for reducing these super pollutants, some dependent on corporations (reducing leaks from gas wells and pipelines), others individual actions (reducing beef consumption and food waste). This rapid action is critical if we are to avoid the risks associated with further warming such as melting of the permafrost at high northern latitudes releasing massive quantities of CO2 and methane, a positive feedback accelerating warming.  Such climate feedbacks could, in turn, result in dangerous tipping points: dramatic changes in ocean ecology, the climate system, and other natural systems with potentially catastrophic consequences.

In the months since our book was published a great deal has happened, both positive and negative.  Two lengthy consensus reports by the Intergovernmental Panel on Climate Change (IPCC), the international process periodically reviewing the status of climate science, have added to our awareness that climate change is here, already causing enormous damages, and only going to get worse.  In remarkably stark terms, we were  told the time for action is running out; any further delay “will miss a brief rapidly closing window to secure a liveable future.” The reports document ecological changes on a massive scale, including the melting of the Arctic tundra, deforestation of the Amazon, and loss of biodiversity.  We have also learned thanks to improved methods for monitoring of the atmosphere that methane emissions have been significantly undercounted – in the process identifying locations where control measures may be most impactful. Most recently, the Russian invasion of Ukraine has increased demand for fossil fuels for at least some time to come.

On the positive side, China, and India joined more than 125 nations to have ratified an international agreement, the Kigali Amendment to the Montreal Protocol, to reduce their emissions of HFCs; the U.S. announced its intention to do so and moved ahead with the regulatory action required.  More than 100 countries representing more than 50 percent of global methane emissions have signed the Methane Pledge with a promise to reduce their methane emissions at least 30 percent from 2020 levels by 2030, which could eliminate over 0.2C of warming by 2050. A growing number of local governments have adopted restrictions on new natural gas hookups to reduce methane emissions.

In short, climate change is here and a potential catastrophe, but we still have the time, resources, and knowledge necessary to prevent the worst.

References

IPCC, Climate Change 2022: Impacts, Adaptation, and Vulnerability (https://www.ipcc.ch/report/sixth-assessment-report-working-group-ii/)

IPCC, AR6 Climate Change 2021: The Physical Science Basis (https://www.ipcc.ch/report/ar6/wg1/)

Alan Miller, Durwood Zaelke, and Stephen O. Andersen, Cut Super Climate Pollutants Now! (Changemakers Books, 2021)

World Bank Group. 2021. World Bank Group Climate Change Action Plan 2021–2025: Supporting Green, Resilient, and Inclusive Development. World Bank, Washington, DC. © World Bank. https://openknowledge.worldbank.org/handle/10986/35799 License: CC BY 3.0 IGO.

KEYWORDS   climate feedbacks, HFCs, IPCC, methane, tipping points