A Sustainable Path to Mitigating Climate Change
Yang Ou
College of Environmental Sciences and Engineering, Peking University, Beijing, China, and Institute of Carbon Neutrality, Peking University, Beijing, China
Winning article: Can updated climate pledges limit warming well below 2°C? (Science, 2021)
“The wave of strengthened climate pledges and net-zero commitments significantly increased our chance of staying under 2°C”
In an era where the palpable effects of climate change are witnessed across the globe, the pressing need for transformative solutions is more critical than ever. Our study, published in Science, underscores a pivotal moment in our collective fight against global warming. Our research represents a collaborative effort involving multiple teams from different institutions worldwide, marking a significant step in an ongoing initiative to track the progress of climate pledges made since the 2015 Paris Agreement (Figure 1).
Figure 1. Rising temperatures demand urgent action: the path to halting global warming.
At the heart of our research lies the multi-faceted challenge of mitigating global warming. The 2015 Paris Agreement set ambitious targets to limit global temperature rise this century to well below 2 degrees Celsius above pre-industrial levels, and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius. However, based on a previous analysis by our group, also published in Science, the initial climate targets set by countries in 2015 were deemed insufficient, projecting a concerning outlook for the future. Here, our work reevaluates the situation in light of over 100 nations’ renewed commitments and net-zero pledges ahead of COP26 in 2021, offering a nuanced understanding of where we stand in our global climate endeavors.
Our study used state-of-the-art computational tools to simulate a range of energy and emissions scenarios and their probabilistic temperature outcomes until 2100, based on the latest updates to the Nationally Determined Contributions. We outline a multifaceted strategy involving the transition to clean energy, enhancement of energy efficiency, and the adoption of carbon sequestration methods, all aimed at capping global warming within the 2 degrees Celsius threshold. Our analysis illuminates a clear path of increased probabilities—from a mere 8% to 34% for staying below 2°C, and from 0% to 1.5% for the 1.5°C limit, under the new pledges if fully implemented and further bolstered by ambitious climate policies beyond 2030. To enhance the likelihood of staying below the 2°C threshold, addressing the gap requires accelerating near-term emission reductions, fostering disruptive technological innovations, and intensifying global cooperation. These actions are essential for setting achievable goals that bolster our environmental resilience.
Our findings in this study are part of a broader, long-term effort to assess and enhance the global response to climate change, emphasizing the critical need for increased ambition and collaborative science to achieve the goals set forth in Paris. For industry and civil society, the transition to a low-carbon economy is feasible and increasingly economically viable. Technological advances, such as cheaper solar panels and electric vehicles, coupled with shifts away from fossil energy, pave the way for practical, scalable solutions. These developments underscore the critical role of ambitious policymaking and the integration of technological innovations in achieving our climate targets.
Recent trends observed at COP28, such as the progress related to the Loss and Damage Fund and concerted international efforts to forge institutional foundations and agreements, are pivotal. These developments aim at reaching a consensus on solid implementation strategies, highlighting a global acknowledgment of the urgent need to address climate impacts more comprehensively. The momentum gained from these discussions and agreements at COP28 demonstrates the international community’s commitment to translating climate ambitions into actionable policies and frameworks.
Our study provides a vital demonstration of how we can maintain the Earth’s climate within a safe operating space, crucial for averting the risks posed by crossing ecological thresholds. By evaluating the updated national commitments to reduce greenhouse gas emissions, we demonstrate the significant role of collective action and technological advancements in mitigating climate change. This analysis not only showcases the interconnectedness of human activities and the Earth’s system but also aligns with the dynamic and iterative nature of the planetary boundaries framework.
Building on this foundation, our research highlights the importance of the Paris Agreement’s ratcheting mechanism, which mandates periodic enhancements in climate ambition. This is reflective of our evolving grasp of the Earth’s climate system and underscores the urgent need for more solid actions. By demonstrating the feasibility of climate pledges and underscoring the essential support of institutional frameworks, we illustrate how these commitments can realistically be achieved and improved over time. This includes providing evidence that current technologies and policies can support the initial targets while also identifying areas where further innovation and policy development are necessary. Our findings advocate for an ongoing reassessment of global efforts to combat climate change, emphasizing that keeping the Earth’s climate within its safe operating limits requires continuous international collaboration and the flexibility to adapt to new technologies and strategies.
The current trends of transitioning towards renewable energy and decarbonization represent a significant development that supports the objectives of planetary boundaries science. This shift from fossil fuels to clean technologies and sustainable practices is a pivotal moment in our collective endeavor to combat climate change. Furthermore, the call for transparent, periodic updates on climate commitments signals a growing worldwide consensus on the need for urgent action.
Looking forward, an integrated approach is essential in addressing climate change, merging the insights of natural sciences with social sciences to achieve a holistic understanding. The critical role of collaboration across disciplines, coupled with the importance of establishing strong communication and trust between scientists, policymakers, and the general public, is foundational. Enhancing this trust involves clear communication, meaningful public dialogues, a transparent research framework, and systematic quality control. Addressing climate change necessitates a collective “all-in” approach, recognizing that individual actions in our daily lives are integral to our shared long-term climate goals.
In summary, mitigating global warming is fraught with challenges, yet our research offers a beacon of hope. As we stand at a crossroads, the choices we make today will determine the health of our planet for generations to come. Our study not only contributes to the scientific understanding of climate mitigation strategies but also serves as a call to action for researchers, policymakers, industry leaders, and individuals alike. Together, we can forge a sustainable path to mitigating climate change, ensuring the Earth remains within its safe operating space for all.
Photo 1. A multi-nation research team showcases our joint commitment to tracking progress on climate pledges since the 2015 Paris Agreement.
