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Records include highest-ever concentrations of key greenhouse gases carbon dioxide, methane and nitrous oxide, and lowest-ever ice mass in Greenland and Antarctica.

Earth’s vital signs worsen amid business-as-usual mindset on climate change

Twenty months after declaring a climate emergency and establishing a set of vital signs for the Earth, a coalition of researchers says “unrelenting business as usual” has led to alarming results.

The international team – led by Oregon State University (OSU) and including the Global Systems Institute (GSI) at the University of Exeter – track 31 vital signs, and their latest paper finds record-breaking results in 18 of these.

Records include highest-ever concentrations of key greenhouse gases carbon dioxide, methane and nitrous oxide, and lowest-ever ice mass in Greenland and Antarctica.

Ruminant livestock (such as cows and sheep) are at record levels – now numbering more than four billion, with a total mass exceeding that of all humans and wild land mammals combined.

The news is not all bad, however, as fossil fuel divestment and fossil fuel subsidies have improved in record-setting ways.

The researchers call for a phase-out of fossil fuels, and a global carbon price high enough to induce widespread decarbonisation.

"There is growing evidence we are getting close to or have already gone beyond tipping points associated with important parts of the Earth system, including warm-water coral reefs, the Amazon rainforest and the West Antarctic and Greenland ice sheets," said William Ripple, distinguished professor of ecology in the OSU College of Forestry.

"We need to stop treating the climate emergency as a stand-alone issue – global heating is not the sole symptom of our stressed Earth system.

"Policies to combat the climate crisis or any other symptoms should address their root cause: human overexploitation of the planet."

Christopher Wolf, a postdoctoral scholar in the College of Forestry, added: "Priorities need to shift toward immediate, drastic reductions in greenhouse gases, especially methane."

GSI director Professor Tim Lenton said: “The recent unprecedented heatwave in Western Canada and USA provides a stark warning that the climate is starting to behave in shocking, unexpected ways.

“We need to respond to the evidence that we are hitting climate tipping points with equally urgent action to decarbonise the global economy and start restoring instead of destroying nature."

The authors highlight vital signs including:

  • 2020 was the second-hottest year in history, with the five hottest years on record all occurring since 2015.
  • In April 2021, carbon dioxide concentration reached 416 parts per million, the highest monthly global average concentration ever recorded.
  • Brazilian Amazon annual forest loss rates increased in both 2019 and 2020, reaching a 12-year high of 1.11 million hectares deforested in 2020.
  • Ocean acidification is near an all-time record. Together with thermal stress, it threatens the coral reefs that more than half a billion people depend on for food, tourism dollars and storm surge protection.

The COVID-19 pandemic had the side effect of providing some climate crisis relief – but this progress might not last.

A major lesson of the pandemic, the authors say, is that even colossally decreased transportation and consumption are insufficient to tackle climate change – and instead transformational system changes are required, even if they are politically unpopular.

Despite pledging to "build back better" by globally directing COVID-19 recovery investments toward green policies, only 17% of such funds had been allocated that way as of early March 2021.

The research team – which includes collaborators from the US, UK, Australia, France, the Netherlands, Bangladesh and Germany – call for a “three-pronged near-term policy approach” that includes a globally implemented carbon price, a phase-out and eventual ban of fossil fuels, and strategic climate reserves to safeguard and restore natural carbon sinks and biodiversity.

"The carbon price needs to be linked to a socially just fund to finance climate mitigation and adaptation policies in the developing world," Ripple said.

"We need to quickly change how we’re doing things, and new climate policies should be part of COVID-19 recovery plans wherever possible.

"It’s time for us to join together as a global community with a shared sense of cooperation, urgency and equity."

The new paper, published in the journal BioScience, is entitled: "World scientists’ warning of a climate emergency 2021."

The 2019 climate emergency paper, also published in BioScience, now has nearly 14,000 scientist signatories from 158 countries.

Date: 28 July 2021

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