World on the brink of an irreversible climate disaster, scientists warn

An international team of scientists, including Associate Professor Thomas Newsome from the University of Sydney, is warning that the Earth is stepping into a critical and unpredictable new phase of the climate crisis, with environmental conditions that have never been encountered in human history. 

The ‘2024 State of the Climate Report: Perilous times on planet Earth’, published in Bioscience, warns of “perilous” times ahead, with current policies leaving the globe on track to see 2.7 degree peak warming by 2100, obliterating the international target made at the Paris Agreement to limit the global temperature increase to 1.5 degrees.

Among the key findings in the report:

• The Earth’s average surface temperature is at an all-time high, with July 2024 seeing three hottest days ever recorded.
• Populations of humans and ruminant livestock (cattle, sheep and goats) are at record levels, with the human population increasing by 200,000 people per day.
• Of the 35 planetary vital signs tracked annually, 25 are at record levels.

The stark findings come as the first Global Nature Positive Summit is held in Sydney (8-10 October) and as international leaders prepare for the UN’s Climate Change Conference (COP 29) from 11-22 November in Baku, Azerbaijan.

Associate Professor Thomas Newsome, from the Global Ecology Lab in the School of Life and Environmental Sciences, and the only Australian co-author of the study, said it was vital governments took the climate crisis seriously: “It has been another year of record high temperatures and extreme weather. Poorer communities are disproportionately affected by extreme weather and climate impacts, even though they have contributed the least to climate change. As we approach another international summit, it is vital that governments implement real change to tackle the climate emergency.” 

Human-caused carbon dioxide emissions and other greenhouse gases have long been identified as the primary drivers of climate change, yet annual consumption of fossil fuels continues to climb and rose 1.5 percent in 2023. 

While there have been some positives in the renewables sector – solar and wind consumption together increased by 15 percent in 2023 from the year before – renewable energy use only accounts for one-fourteenth of fossil fuel use. The recent increase in the use of renewables is also largely attributed to an overall increase in demand for power, rather than because these energy sources are replacing fossil fuels. 

Other pressures on the climate, such as livestock grazing and deforestation, have also increased. Annual tree cover loss across the globe rose from 22.8 million hectares in 2022 to 28.3 million in 2023, at a time when concentrations of atmospheric carbon dioxide and methane are at their highest recorded levels. 

Much of the globe’s deforestation is due to the expansion of agriculture, with forests and bushlands cleared to make way for grazing livestock. The report has highlighted that the population of ruminant livestock (cattle, sheep and goats) is now at an historic high and is increasing by 170,000 per day. 

The report’s co-lead author Professor William Ripple, from the Oregon State University College of Forestry, said: “A large portion of the very fabric of life on our planet is imperilled. We’re already in the midst of abrupt climate upheaval, which jeopardises  life on Earth like nothing humans have ever seen. Ecological overshoot, taking more than the Earth can safely give, has pushed the planet into climatic conditions more threatening than anything witnessed even by our prehistoric relatives.”

Ahead of COP 29 in November, the report’s authors are urging governments to commit to actions to limit the amount of damage caused by climate change, including shifting away from fossil fuels to low-carbon renewables, restoring biodiverse ecosystems that play key roles in carbon cycling and storage, promoting sustainable ecological economics and reducing waste and overconsumption by the wealthy.

Joint lead author Dr Christopher Wolf, from the Terrestrial Ecosystems Research Network in Oregon, said: “Despite six reports from the International Panel on Climate Change, hundreds of other reports, tens of thousands of scientific papers and 28 annual meetings of the UN’s Conference of the Parties, the world has made very little headway on climate change.

“Humanity’s future depends on creativity, moral fibre and perseverance. If future generations are to inherit the world they deserve, decisive action is needed, and fast.”