In a pivotal turn in the climate change battle, the United Nations admits Earth has missed the chance to avoid some severe impacts of global warming. The focus now shifts to reducing temperatures from the danger zone, according to officials.
Exceeding the Paris Climate Agreement’s Safe Threshold
Earth is poised to surpass the safe temperature limits set by the 2015 Paris climate accord, primarily due to the warming effects of coal, oil, and gas use. This stark reality forms the backbone of a groundbreaking report by the United Nations Environment Programme.
UN Secretary-General António Guterres remarked, “Humanity is speeding past the limit to avoid climate catastrophe.”
The report highlights the necessity of managing excessive warming and returning temperatures to safe levels, despite expecting decades of severe weather events, rising sea levels, and glacial melting.
Embracing a Warmer Earth
Richard Betts, a climate scientist from the University of Exeter and a co-author of the report, emphasizes that while we must adapt to a warmer world, proactive measures can still significantly curb climate impacts.
Following the Paris climate accord, the UN tasked its climate scientists with studying various warming limits. The consensus emerged around a 1.5 Celsius (2.7 Fahrenheit) goal above mid-19th century temperatures, with scientists noting severe impacts at 2 degrees Celsius (3.8 degrees Fahrenheit) compared to 1.5 degrees.
Current calculations indicate the world is at 1.4 C (2.5 F) above pre-industrial levels, based on a 20-year average.
Facing Reality: Crossing the Threshold
Experts agree that limiting warming to 1.5 degrees is no longer feasible. After years of optimism, UN officials now recognize the inevitability of exceeding the 1.5 threshold in the near future.
Under the most optimistic scenario of this report, warming peaking at 1.8 C (3.2 F) by mid-century is contingent upon highly ambitious climate goals. Conversely, existing policies suggest temperatures could rise to 2.6 C (4.7 F) by 2100.
The UN urges policymakers to prepare for a future that surpasses the 1.5 mark, eventually stabilizing temperatures below it by the century’s end. This process, known as “overshoot,” envisions a temporary increase before cooling back down.
UNEP Executive Director Inger Andersen emphasizes a new approach of addressing the 1.5 target from above, rather than averting it entirely.
Andrew Weaver, a climate scientist not involved with the study, emphasizes, “Every tenth of a degree we avoid still means less damage.”
Strategizing to Limit Climate Impacts
Limiting peak temperatures and reducing the duration above 1.5 degrees are seen as vital strategies, Andersen says. However, the world is expected to endure an overshoot period for many decades.
Report co-author Joeri Rogelj from Imperial College London points out that every five years of inaction adds one-tenth of a degree to peak warming.
Efforts now aim to minimize overshoot, not achieving a safe world, but ensuring increased safety compared to perpetual warming above 1.5 degrees.
Andrew Weaver reflects on the report’s tone of desperation, frustration, and urgency over resignation.
Adapting to a World with Heightened Extremes
Governments need to escalate efforts to adapt to worsening conditions, especially impacting the impoverished. Some climate change repercussions remain inevitable, says Andersen.
The report outlines a stage called “coping and containment.” Frequent extreme weather events during overshoot will heighten mortality, illness, and hunger, while water scarcity and economic challenges intensify. Coral reefs face extinction.
The report also forewarns about “tipping points” with irreversible consequences, potentially impacting the West Antarctic and Greenland ice sheets, the Amazon rain forest, and the Atlantic Ocean circulation system.
Affected areas could become uninsurable or even uninhabitable.
Cooling the Planet: Carbon Removal Solutions
The last phase of overshoot involves active carbon dioxide removal, traditionally through afforestation, yielding minimal temperature reductions. Emerging carbon removal technologies are cited as necessary.
Stanford climate scientist Rob Jackson views fostering overshoot as an optimal scenario though not imminently achievable. He underscores the challenge of halting and reversing global emissions to secure the future.