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Scientists warn of Earth's unequivocal climate emergency

27 October 2022
Sixteen of the planet’s 35 vital signs are at record extremes

Earth's vital signs have deteriorated to the point humanity is "unequivocally" facing a climate emergency, an international coalition of researchers warns in a report published today.

The World Scientists’ Warning of a Climate Emergency 2022 report, published in the journal BioScience, notes 16 of 35 planetary vital signs the authors use to track climate change are at record extremes.

These signs include human population growth, greater consumption of gas, increasing greenhouse emissions including carbon dioxide and methane, shrinking ice and glaciers, rising sea levels, warming oceans, and climbing numbers of hoofed livestock.

“They are all bad, and point to a worsening of the climatic extremes that exacerbate the effects of extreme weather events – fires, floods and droughts,” said Dr Thomas Newsome, a Senior Lecturer in the University of Sydney’s School of Life and Environmental Sciences.

“The majority of these graphs need to trend in the opposite direction.

“In terms of the changes, if there are major shifts – such as decreases in greenhouse gasses – we would expect the graphs to be trending away from record highs. Until this happens, the effects of climate change will only worsen.

“We urge our fellow scientists around the world to speak out on climate change.”

Dr Thomas Newsome, Senior Lecturer in the University of Sydney’s School of Life and Environmental Sciences.

Dr Thomas Newsome, Senior Lecturer in the University of Sydney’s School of Life and Environmental Sciences.

Dr Newsome co-authored the report with a dozen global scientists, led by Oregon State University’s Professor William Ripple and postdoctoral researcher Christopher Wolf.

“Look at all of these fires, floods and massive storms,” Professor Ripple said. “The spectre of climate change is at the door and pounding hard.”

“As we can see by the annual surges in climate disasters, we are now in the midst of a major climate crisis, with far worse to come if we keep doing things the way we’ve been doing them,” Mr Wolf said. “We implore our fellow scientists to join us in advocating for research-based approaches to climate and environmental decision-making.”

Charts showing the growth of the human population (left) and governments who have declared a climate emergency (right).

Charts showing the growth of the human population and governments who have declared a climate emergency [Credit: World Scientists’ Warning of a Climate Emergency 2022].

Other co-authors are from University of California at Los Angeles (UCLA), Independent University Bangladesh, the University of Cambridge, the University of Exeter, Bezos Earth Fund and the Potsdam Institute for Climate Impact Research.

The report is an update of a paper published in BioScience three years ago. The Alliance of World Scientists, an independent organisation formed to be a collective voice on environmental sustainability and human well-being, continues to collect co-signers on the 2019 paper. To date more than 14,700 scientists from 158 countries have signed.

The warning comes five years after Professor Ripple published World Scientists’ Warning to Humanity: A Second Notice in BioScience, which has been co-signed by more than 15,000 scientists in 184 countries.

Charts showing carbon dioxide in parts per million (left) and ocean heat (right).

Charts showing carbon dioxide in parts per million and ocean heat [Credit: World Scientists’ Warning of a Climate Emergency 2022].

The present state of climate change

Global greenhouse gas emissions have increased by about 40 percent over the last three decades, despite ringing alarm bells, when more than 1,700 scientists signed the World Scientists’ Warning to Humanity in 1992.

In March 2022, carbon dioxide levels reached 418 parts per million – the highest global concentration on record, the authors point out. This year is on course to be one of the hottest in recorded history, and ocean temperature has reached its highest on record.

Climate change has already increased the frequency and intensity of weather events across the globe, a trend the report notes is a likely result of interconnected processes such as overall warming, rain patterns, rising seas and alterations in jet streams.

“Rather than just being more frequent, some extreme weather events are now more intense or sometimes occur closer together in time and space,” said the authors.

“This compounds damage and decreases recovery time. It may increase the likelihood of extreme risks such as simultaneous global failure of crop yields across multiple major food producing regions.

“As has been demonstrated by the surge in yearly climate disasters, we are now in a major climate crisis and global catastrophe with far worse in store if we continue with business as usual.”

While the COVID-19 pandemic caused global consumption of fossil fuel to fall in 2020, the authors noted this was temporary and increased significantly in 2021.

“The COVID lockdown period shows that the closure of transport globally and people moving less did little – we need major changes in the way we produce energy,” said Dr Newsome.

The report points out current policies will push the planet to about three degrees Celsius of warming by 2100.

Philip Ritchie

Media and PR Adviser (Science)

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