As global warming approaches 1.5°C and the urgency to address climate change grows, ambitious strategies for reducing greenhouse gas emissions become more important than ever. One increasingly discussed approach is the concept of “overshoot,” where temperatures exceed a target temporarily before returning to back below it later on. But what are the risks of overshoot, and are we underestimating its long-term consequences?
An article published last year in One Earth by our CT3 leader, Joeri Rogelj, provides key insights into the assumptions and uncertainties surrounding overshoot scenarios, shedding light on their potential risks for ecosystems, societies, and global equity.
Key Insights from the Article
The Illusion of Manageability:
Overshoot scenarios often assume that large-scale carbon dioxide removal (CDR) can return global warming to safer levels. However, these models may underestimate the feasibility challenges of achieving such amounts of CDR, and overestimate the ability of ecosystems and societies to cope with periods of excessive warming.
Irreversible Risks:
Even short-term temperature increases can trigger irreversible tipping points in ecosystems, such as permafrost thaw or coral reef collapse, with profound implications for biodiversity and human livelihoods.
Equity Concerns:
Overshoot pathways often place disproportionate burdens on future generations and vulnerable communities, raising ethical questions about their viability as an equitable policy choice.
A Broader Perspective
For those interested in further exploring this topic, Joeri Rogelj expands on these issues in a Climate and Environment at Imperial blog article, which provides an accessible overview of the challenges and misconceptions surrounding overshoot.
To delve deeper into the latest scientific findings, check out this recent Nature article, which offers the most up-to-date analysis of overshoot scenarios and their implications for global climate action.
Why This Matters
Understanding the risks and trade-offs of overshoot is critical for shaping climate policies that prioritize sustainability and equity. By sharing this research, we aim to inform the community about the complexities of overshoot scenarios, their relevance to ongoing debates, and the need for ambitious near-term emissions reductions to achieve the Paris Agreement goals.
