SHORT-LIVED CLIMATE POLLUTANTS AND THEIR IMPACTS ON CLIMATE CHANGE

ABSTRACT

This study examines the critical role of short-lived climate pollutants (SLCPs) in driving near-term climate change and their far-reaching impacts on health, ecosystems, and sustainable development. SLCPs, including methane (CH₄), black carbon, hydrofluorocarbons (HFCs), and tropospheric ozone (O₃), have a disproportionately high impact on global warming despite their short atmospheric lifetimes. These pollutants not only contribute to temperature rise but also exacerbate extreme weather conditions, alter precipitation patterns, and threaten vulnerable ecosystems. Additionally, SLCPs significantly affect air quality and public health, leading to respiratory and cardiovascular diseases, as well as agricultural productivity loss due to ozone-induced crop damage. The study highlights the substantial co-benefits of SLCP mitigation, such as improved air quality, enhanced food security, and economic savings. Strategies like cleaner cooking technologies, stricter emissions regulations, and methane capture from landfills and livestock management can simultaneously curb climate change and advance sustainable development goals (SDGs). Effective SLCP mitigation could prevent millions of premature deaths, enhance energy access, and support climate adaptation efforts. Findings emphasize the need for integrated climate policies targeting both SLCPs and long-lived greenhouse gases (LLGHGs) to achieve rapid and long-term climate benefits. Addressing SLCPs could prevent up to 0.6°C of global warming by 2050, complementing CO₂ reduction efforts under the Paris Agreement. However, challenges such as financial constraints and limited technical capacity in developing countries require enhanced international collaboration, financial support, and policy alignment. Strengthening global initiatives like the Climate and Clean Air Coalition (CCAC) and expanding climate finance mechanisms are essential for scaling up SLCP mitigation. This study underscores the urgency of prioritizing SLCP reduction as part of comprehensive climate strategies to ensure a sustainable and equitable future.

CHAPTER ONE

Introduction/Background of the Study

Short-lived climate pollutants (SLCPs) are a group of atmospheric compounds that have a relatively short lifespan in the atmosphere but exert a disproportionately strong influence on global warming and climate change. Unlike long-lived greenhouse gases such as carbon dioxide (CO₂), which can persist in the atmosphere for centuries, SLCPs include methane (CH₄), black carbon, hydrofluorocarbons (HFCs), and tropospheric ozone (O₃), which typically remain in the atmosphere for days to a few decades (Shindell et al., 2012). Despite their shorter atmospheric lifetimes, these pollutants contribute significantly to radiative forcing, a measure of the Earth's energy balance, and are responsible for a substantial fraction of current global warming (UNEP, 2011). For instance, methane has a global warming potential 28-34 times greater than CO₂ over a 100-year period, while black carbon, a component of particulate matter, absorbs sunlight and directly heats the atmosphere (IPCC, 2021).

The impacts of SLCPs extend beyond their contribution to global temperature rise. They also play a critical role in regional climate change, air quality, and public health. Black carbon, for example, not only accelerates the melting of snow and ice by darkening their surfaces but is also a major component of fine particulate matter (PM₂.₅), which is linked to respiratory and cardiovascular diseases (Bond et al., 2013). Similarly, tropospheric ozone, formed through chemical reactions involving methane and other precursors, is a potent greenhouse gas and a key component of smog, posing significant risks to human health and agricultural productivity (Fiore et al., 2015). The dual nature of SLCPs—contributing to both climate change and air pollution—makes their mitigation a unique opportunity to achieve co-benefits for climate, health, and sustainable development (UNEP, 2018).

Addressing SLCPs has gained increasing attention in recent years as a complementary strategy to CO₂ mitigation efforts. While reducing CO₂ emissions remains essential for long-term climate stabilization, targeting SLCPs offers the potential to slow the rate of near-term warming and avoid some of the most severe impacts of climate change within decades (Ramanathan & Xu, 2010). This is particularly important for vulnerable regions, such as the Arctic and high mountain areas, where SLCPs contribute to accelerated ice melt and sea-level rise (AMAP, 2015). Furthermore, many SLCP mitigation measures, such as improving waste management to reduce methane emissions or transitioning to cleaner cooking technologies to reduce black carbon, are cost-effective and readily available (Shindell et al., 2017). As such, integrating SLCP mitigation into broader climate and air quality policies represents a critical step toward achieving the goals of the Paris Agreement and improving global health outcomes.

In this context, understanding the sources, impacts, and mitigation pathways of SLCPs is essential for developing effective climate and environmental policies. This study seeks to explore the role of SLCPs in driving climate change, their interactions with other environmental challenges, and the potential benefits of targeted mitigation strategies. By synthesizing existing research and identifying gaps in knowledge, this work aims to contribute to the growing body of evidence supporting urgent action on SLCPs as part of a comprehensive approach to addressing climate change and its associated risks.

1.2 Objectives of the Study

The objectives of this seminar were as follows;

1. To raise awareness about the role of short-lived climate pollutants (SLCPs) in driving climate change and their disproportionate impact on global warming, despite their shorter atmospheric lifetimes
2. To explore the interconnected impacts of SLCPs on climate, air quality, and public health, emphasizing the co-benefits of mitigation strategies.
3. To identify and evaluate practical, cost-effective mitigation measures for SLCPs and their integration into broader climate and environmental policies.

1.3 Significance of the Study

The significance of this study lies in its potential to deepen the understanding of short-lived climate pollutants (SLCPs) and their multifaceted impacts on climate change, air quality, and human health. By examining the sources, behavior, and effects of SLCPs, this research provides critical insights into how these pollutants contribute to near-term warming and exacerbate climate-related risks. Unlike long-lived greenhouse gases, SLCPs offer a unique opportunity to achieve rapid climate benefits through targeted mitigation efforts, making this study particularly relevant in the context of accelerating global climate action. The findings will contribute to the growing body of knowledge on SLCPs, helping to bridge gaps in current research and inform evidence-based policies that address both climate change and sustainable development goals.

For policymakers, the study’s findings will be instrumental in designing integrated climate and air quality strategies that prioritize SLCP mitigation alongside CO₂ reduction efforts. By highlighting the co-benefits of SLCP mitigation, such as improved public health and enhanced agricultural productivity, the research will support the development of policies that align with the objectives of the Paris Agreement and the Sustainable Development Goals (SDGs). For instance, reducing methane emissions from agriculture and waste management or transitioning to cleaner energy sources to curb black carbon emissions can yield immediate climate and health benefits, particularly in low- and middle-income countries. This study will provide actionable recommendations for policymakers to implement cost-effective and scalable solutions that address both global and regional challenges.

The private sector and industry stakeholders will also benefit from the study’s findings, as it identifies opportunities for innovation and investment in SLCP mitigation technologies and practices. For example, industries involved in energy production, waste management, and transportation can leverage the research to adopt cleaner technologies, reduce emissions, and enhance their sustainability credentials. Additionally, the study’s emphasis on the economic and health co-benefits of SLCP mitigation can encourage businesses to align their operations with climate-friendly practices, fostering corporate social responsibility and long-term resilience.

For the scientific community, this study will serve as a valuable resource for advancing research on SLCPs and their interactions with other environmental and climatic factors. By synthesizing existing data and identifying research gaps, the study will guide future investigations into the atmospheric dynamics of SLCPs, their regional impacts, and the effectiveness of mitigation strategies. This will contribute to a more comprehensive understanding of the role of SLCPs in the global climate system and support the development of robust models for predicting their impacts.

Finally, the study holds significant value for civil society and the general public by raising awareness about the urgent need to address SLCPs as part of broader climate action. By highlighting the direct links between SLCPs, air pollution, and health, the research can empower communities to advocate for cleaner environments and hold decision-makers accountable. In regions disproportionately affected by SLCPs, such as those with high levels of household air pollution from solid fuel use, the study’s findings can drive grassroots initiatives and community-led solutions to reduce emissions and improve quality of life. Overall, this study will serve as a catalyst for multi-stakeholder collaboration, fostering a collective effort to mitigate SLCPs and achieve sustainable development for present and future generations.