Climate scientists warn: World on track to exceed 1.5°C target

In a report (November 2023) from the Climate Crisis Advisory Group (CCAG), the risks and consequences of temporarily exceeding the 1.5°C limit for global warming are assessed. The report, “The Overshoot: Crossing the 1.5°C threshold – and finding our way back”, states that despite the ambitions of the Paris Agreement, the world is on track to reach 1.5°C of warming as early as 2035.

Professor Johan Rockström, director of the Potsdam Institute for Climate Impact Research and one of the report’s authors, emphasizes the importance of managing and mitigating the effects of an overshoot. “There is absolutely no guarantee that we will return below 1.5°C. If the sluggish development of emissions reductions continues, even an overshoot scenario will quickly become unattainable.”

Planetary Health 2023: Boundaries Exceeded

The report highlights the latest scientific “health check” of the planet, conducted in 2023 and based on the concept of “Planetary Boundaries”. These nine interconnected boundaries define a “safe operating space for humanity”.

Compared to 2009, when three of the nine planetary boundaries had been exceeded, the 2023 assessment shows that six out of nine boundaries have now been crossed. Earth’s natural life-supporting systems have been seriously compromised. The report warns that the planet’s resilience is weakening, making us even more vulnerable to the effects of climate change.

Degrees of Uncertainty: The Credibility Gap in Climate Pledges

An analysis of the credibility of individual nations’ climate goals and commitments reveals more about the likelihood of an overshoot. Based on current policies, global warming could still rise by 2.6°C by the end of the century.

Even in the most optimistic scenario, where all current pledges are assumed to be implemented, the evidence points to a temperature increase of 1.7°C. The report emphasizes that the commitments made under the Paris Agreement are likely to be missed and that the world requires even greater ambitions.

Risks, Effects, and Consequences of Overshoot

The report warns that exceeding the 1.5°C limit will accelerate the effects and risks of climate change, including extreme weather events. One of the greatest dangers is the risk of passing various “tipping points” – irreversible shifts in the planet’s biological and physical systems that become self-reinforcing.

The effects of even a short-term overshoot can be devastating, especially for poor and vulnerable communities already bearing an increasingly unbearable burden of global warming. Studies point to difficult trade-offs between short-term mitigation costs and long-term damages, with disproportionate consequences for developing countries.

A Way Forward: Managing and Mitigating Overshoot

To minimize overshoot and mitigate its effects, CCAG advocates a “4R Planet Strategy” focusing on four key areas: Reduction, Removal, Repair, and Resilience.

The report provides an overview of some of the climate actions and interventions that can help manage overshoot, from carbon capture and nature-based solutions to more controversial methods such as solar radiation management. Despite uncertainties, the importance of exploring all available options is emphasized.

Conclusions

The CCAG report shows that the risk of temporarily exceeding the 1.5°C limit is imminent. Overshoot will intensify existing challenges and potentially expose humanity to new and irreversible damages. To avoid catastrophic consequences, rapid and extensive efforts are required to reduce emissions, remove greenhouse gases from the atmosphere, repair damaged climate systems, and strengthen our resilience.

The acute state of the climate crisis is underscored by the record-breaking temperatures and extreme weather events during 2023. It was the warmest measured calendar year since 1850, with a global average temperature of 14.98°C – a full 1.48°C warmer than the pre-industrial level. At the same time, the year was marked by devastating heat waves, floods, droughts, and wildfires around the world.

These worrying signs suggest that we are very close to passing the Paris Agreement’s 1.5-degree target, if it has not already happened. Unfortunately, developments are moving in the wrong direction. The climate crisis is acute and requires powerful measures at all levels of society to avoid a catastrophe.

The trend of record-high temperatures has continued during 2024. January was the warmest January month measured globally since records began in 1850, and the first three months have had exceptionally high global temperatures, around 1.6°C above pre-industrial levels. February was the warmest February month ever and the ninth consecutive month with record heat.

The probability is high that 2024 will be the warmest or second warmest year so far, despite the strong El Niño event that contributed to the record heat now weakening. According to various statistical analyses, there is between a 55% and 60% chance that 2024 will be the warmest year and up to a 99% chance that it will be among the five warmest.

Carbon Brief estimates that 2024 is very likely to reach a global average temperature around 1.5°C above pre-industrial levels.

These alarming trends underscore the severity of the climate crisis and the need for immediate action. As the CCAG report shows, exceeding the 1.5°C limit will have devastating consequences, especially for the world’s poor and vulnerable.

To slow down warming and avoid catastrophic consequences, rapid and radical reductions in greenhouse gas emissions are required globally.

It is now or never – humanity must act resolutely before the window to secure a sustainable future closes for good. We have no time to lose.

Picture of Per-Olof Hall

Per-Olof Hall

Writes about health and sustainability, combining unique insights with over 15 years of experience as owner and consultant at PlanetPeople AB.