As 25 Earth vital signs worsen, scientists warn of ‘irreversible climate disaster’
“We are on the brink of an irreversible climate disaster. This is a global emergency beyond any doubt. Much of the very fabric of life on Earth is imperiled,” the authors write. “The global failure to support a rapid and socially just fossil fuel phasedown has led to rapidly escalating climate-related impacts.”
The researchers evaluated 35 planetary vital signs. and found 25 are at record levels, driving a series of increasingly severe climate-linked disasters over the past year. These extreme events affected millions of people across the globe and included devastating floods in East Africa, rampant wildfires in the Amazon and Pantanal ecosystem, and heatwaves across Europe and Asia. Back-to-back Hurricanes Helene and Milton battered the U.S. Southeast — two more examples of supercharged storm systems.
“It’s very likely that climate change is making powerful hurricanes like Helene and Milton more common and devastating,” study author William Ripple, distinguished professor at Oregon State University and director of the Alliance of World Scientists, told Mongabay in an email.
“The climate crisis is becoming increasingly severe, and we are now faced with many climate-related disasters along with catastrophic risks in the longer term. We are continuing to go in the wrong direction, with enormous fossil fuel emissions and unsustainable consumption by the wealthy,” he added.
For Helen Adams, senior lecturer in Disaster Risk Reduction and Climate Change Adaptation at King’s College London, who was not involved in the report, the science presented by the report in Bioscience is clear, though she takes issue with its tone.
“I don’t disagree with the science, but for me the question is what do we gain with these doomsday narratives?” she says, adding that there is need to strike a balance between detailing the gravity of the situation and motivating climate action. “We need to reclaim a more positive narrative that has, to an extent, been co-opted by oil and gas companies about a better future, about future possibilities.”
Earth’s deteriorating vital signs
The report authors assessed 35 planetary vital signs that indicate the current state of natural systems and human influences on them that, taken together, offer insight into how Earth’s climate is changing in response to human activities, says Milton.
That picture makes for grim reading. The researchers note that consumption of fossil fuels (coal, oil and natural gas) grew by 1.5% in 2023, hitting an all-time high. Although renewable energy sources also grew, this is mostly attributed to increasing energy demand, with fossil fuel sources dwarfing alternatives by roughly 14 times.
Greenhouse gas emissions and atmospheric concentrations continue to climb with both carbon dioxide and methane at “record highs.” Increasing methane emissions are “troubling” as methane is a far more potent greenhouse gas than CO2, despite lasting only a decade in the atmosphere.
Earth surface temperatures also set new records, with 2024 on track to be the hottest on record (with 2023 setting the previous high), the report notes. Biodiversity continues to suffer with global forest loss of 28.4 megahectares in 2023, compared to 22.8 megahectares in 2022. Last year’s sea surface temperatures hit new heights and combined with record extremes of ocean acidity to stress marine life.
“We are concerned about recent trends in many planetary vital signs, including record-breaking greenhouse gas concentrations, tree cover loss due to wildfires and ice loss,” Ripple says. “We are especially troubled by global consumption of coal and oil reaching all-time highs in 2023.”
The authors also cite the results of a largescale survey of 380 climate scientists, conducted by the Guardian newspaper, 80% of whom hold the bleak view that average global temperatures will increase 2.5° C (4.5° F) by the end of the century, echoing concerns of the 2023 UN Emissions Gap Report.
Climate change-fuelling emissions are likewise driving dangerous feedback loops, and the report references 28 that have now been observed, including thawing Artic permafrost and methane emissions from tropical wetlands. These feedbacks add to human emissions and contribute to the looming threat of climate tipping points. Five of sixteen such potentially irreversible thresholds could be crossed with an increase of just 1.5° C (2.7° F), including the eventual loss of the Greenland and West Antarctic Ice Sheets, the report warns. Earth temperatures have already increased over preindustrial levels by 1.3° C.
“Overall, this points to a complex situation where climate controlling feedback loops and tipping point systems are interconnected in a way that could trigger self-perpetuating processes that amplify warming beyond human control,” the authors write. This severe and worsening climate scenario could ultimately help trigger “societal collapse”, a possibility that the report notes is the focus of increasing research, as climate change combines with other threats in a global polycrisis.
Adams, however, pushes back on this finding. “There isn’t the evidence to suggest that the impacts of climate change will lead to societal collapse,” she says, emphasizing that underlying drivers of inequality and social injustice must be addressed, in addition to climate change. In her view, the climate change discussion needs to be reframed around food prices, energy security, jobs, healthcare, and continuity in cultural practices to “focus on the things people care about.”
Amid the gloom there are bright spots. One of these, says Ripple, is the recent declines in deforestation in the Brazilian Amazon — a critically important biome that plays a vital role in both carbon and methane cycling globally.
“From climate and biodiversity perspectives, the Amazon rainforest is one of Earth’s most important ecosystems. So, we are encouraged by the declining deforestation rate in the Brazilian Amazon,” Ripple says. “Increasing solar and wind energy consumption is also a positive trend, although fossil fuel subsidies are likely slowing the adoption of renewables.”
Reversing destabilizing global trends
Nothing short of “immediate, high impact, and socially just climate policies” are needed to avoid a further decline of Earth’s vital signs, says Ripple. The report authors describe a range of mitigation measures, with rapid phase down of fossil fuel use a priority.
“[R]educing methane emissions is critical,” as this greenhouse gas is responsible for an estimated 30% of current warming. Drastically cutting methane emissions could have an outsized impact on easing the climate crisis.
“In addition, the adoption of a sufficiently high global carbon price could help to dramatically reduce emissions while providing further funding for climate action,” Ripple notes.
Protecting, restoring, and rewilding ecosystems; reducing overconsumption; reforming food production; and inclusion of climate change in education curriculums are all encouraged.
The report also suggests “stabilizing and gradually reducing the human population,” by empowering education and rights for girls, a contentious and controversial viewpoint. “I would push back strongly on the population control point,” Adams says. “Unsustainable use and unequal distribution of resources are the problem, not overpopulation.”
The report authors say their aim is “to communicate directly to researchers, policymakers and the public” in order “to alert humanity to the growing threats that we face as clearly as possible and to show leadership in addressing them.”
Referring to the upcoming UN COP29 climate summit — scheduled to begin this November in Baku, Azerbaijan — Ripple says he hopes to see a binding agreement on global fossil fuel phaseout, along with a rapid timeline to kickstart climate action. “We also hope that wealthy countries will increase their climate finance pledges to better support the Global South in scaling up renewable energy capacity and adapting to climate change.”
