Climate change: Window to act is closing rapidly, warn scientists (2024)

The target of limiting global temperature rises to 1.5°C above pre-industrial levels is likely to be breached within the next decade, the Intergovernmental Panel on Climate Change (IPCC) has warned.1

Calling on governments to fast track climate efforts before it is too late the UN body’s latest report said, “There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all.” And it delivers a stark warning: “The choices and actions implemented in this decade will have impacts now and for thousands of years.”

The fourth and final instalment of the mammoth sixth assessment report pulls together the findings of six previous reports from the IPCC, including three special reports. This synthesis report is intended to inform the next UN climate summit, COP28, which will be hosted by the United Arab Emirates in Dubai from 30 November.

The UN secretary general Antonio Guterres said that the synthesis report was “a survival guide” for humanity and will be a resource for policy makers. “This report is a clarion call to massively fast track climate efforts by every country and every sector and on every timeframe. Our world needs climate action on all fronts: everything, everywhere, all at once.”

In 2018 the IPCC set out the scale of the challenge to keep global warming to 1.5°C. This latest comprehensive report said that challenge has become even greater because of a continued increase in greenhouse gas emissions. The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change.

Global warming is now at 1.1°C above pre-industrial levels and this has resulted in more intense extreme weather events that are impacting nature and people in every region of the world.

The report said that models show 1.5°C is likely to be reached in the near term and every increment of global warming will intensify multiple and concurrent hazards. This will mean more intense heat waves, heavier rainfall, and other weather extremes leading to more people dying from extreme heat, greater food and water insecurity, and the occurrence of more climate related waterborne and vector borne diseases.

The report outlined the significant impacts that climate change was having already and predicted how things will get much worse. For example, by 2100 extreme coastal flooding that used to occur once every hundred years is projected to occur at least annually in more than half of the world’s tidal gauge locations—places where sea level recordings are made.

Peter Thorne, one of the report’s authors, told the IPCC press conference that almost irrespective of what is done, 1.5°C warming will be reached in the first half of the next decade. “The question is whether we reach it, or just over, and then start to come down or whether we blast through and get to 2°C or more.” He added, “The future is in our hands. The rest of this decade is key.”

Hoesung Lee, the chair of the IPCC, said that the report offered both hope and a warning. “We know how to solve the problems. But we are walking when we should be sprinting.”

The report said that the solution lies in climate resilient development. This involves integrating measures to adapt to climate change with actions to reduce greenhouse gas emissions in ways that provide wider benefits. For example, improving cycling routes and public transport enhances air quality with benefits to health as well as reducing carbon emissions.

Christopher Trisos, one of the report’s authors, said, “There are multiple co-benefits both for ecosystems and for human health by integrating adaptation and mitigation. For example, reducing greenhouse gas emissions, which are often co-emitted with other near surface air pollutants, can have huge benefits for improving human health. And shifts to sustainable healthy diets can also improve biodiversity by opening up land for ecosystem restoration.

“The greatest gains in wellbeing could come from prioritising climate risk reduction for low income and marginalised communities, including people living in informal settlements.”

If climate goals are to be achieved, both adaptation and mitigation financing would need to increase many fold, the report said. Lee told the press conference that between three and six times the current amount of financing was needed. “Money can’t solve everything but it is critical. But it is not just about the quantity of money it’s also about how it is allocated,” he said.