Irreversible climate disaster

The global environmental crisis keeps escalating. A series of multilateral conferences in the final quarter of last year failed to make any serious difference. The interrelated topics were biodiversity, climate, plastic waste and desertification.

The conferences did not heed scientific alarm bells. The most important warning was perhaps the 2024 State of the Climate Report, which was written by a team of scientists led by William Ripple of Oregon State University and published in the journal BioScience.

The report begins with: “We are on the brink of an irreversible climate disaster.” To judge by “planetary vital signs”, global heating is now in a new phase. The signs include global temperatures, pollution levels, greenhouse-gas emissions, fossil-fuel subsidies, loss of forest cover, meat production and many others. Of 35 such vital indicators, 25 now exceed the sustainability threshold.

Climate scientists thus increasingly doubt global warming can be limited to 1.5 °C above pre-industrial levels. According to the report, 80 % of the scientific community expect temperature to rise by at least 2.5 °C, with half predicting a rise of 3 °C. 

Feedback loops and tipping points

The report’s discussion of feedback loops and tipping points is particularly alarming. Feedback loops are circular, self-reinforcing trends. Tipping points are marks after which a trend cannot be reversed anymore. 

The report identifies at least 28 feedback loops that are accelerating global heating. It warns that several tipping points are likely to be crossed at 1.5 °C. The tipping points include the melting of the Greenland and West Antarctic ice sheets, the thawing of boreal permafrost or the destruction of coral reefs. 

Indeed, triggering a single tipping point could set off a cascade of irreversible changes. That would be the case, for example, if the melting of the Greenland ice sheet disrupted ocean currents and undermined the stability of the Amazon rainforest. The consequences for humanity would be devastating, not only in terms of extreme weather. We would also see famines, mass migration and violent conflict. The authors call for more research on feedback loops and tipping points.

Dangerous trends

The report considers oceans and forests and points out dangerous trends. The survival of coral reefs hangs by a thread. Heat and acidification lead to mass-death events of marine wildlife in other ways too. Earth’s tree cover declined by more than 40 % to 28.3 mega hectares in 2023. Wildfires caused not quite half of this loss. The carbon set free by forest destruction, of course, accelerates global heating. 

The scholars welcome the increase in renewable energy use but point out that fossil fuels continue to be the primary problem. Fossil-fuel consumption exceeded renewables by a factor of 14 in 2023. 

Social-justice crisis

The report emphasises that the climate crisis is a social justice crisis too. Poor communities in Africa, Asia and Latin America have done very little to cause the problems but are suffering the worst impacts. The authors speak of a “profound polycrisis” that threatens the stability of human civilisation itself.

The scholars want everyone to know that, though our situation is serious, we have both the knowledge and capability to tackle climate change. Solutions exist, and many are becoming economically viable. According to the report, climate change should figure prominently in secondary-school curricula as well as in higher learning. What is needed is decisive action, and the better people understand what is at stake, the more likely such action becomes. 

The scientists work in good faith. A peer-review by other scholars ensured that the report is evidence-based, nuanced and sober. Unfortunately, bad-faith propaganda by interest groups often proves more forceful. Lobby organisations praising the merits of conventional growth too often prevail at global conferences, wilfully ignoring that what they propose is leading to disaster. Their influence is multiplied by the fact that a small number of petrostates can block multilateral consensus as was seen at last year’s UN climate summit in Baku. 

Link
State of the climate report 2025:
https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biae087/7808595 

Roli Mahajan is a journalist based in Lucknow, India.
roli.mahajan@gmail.com