Planetary ‘Vital Signs’ Indicate that Climate Tipping Point is Imminent
An unprecedented surge in climate-related disasters, including wildfires and flooding, has been recorded since 2019. 

A new study, conducted by an international group of scientists, found that key indicators of the state of the climate crisis were reaching critical tipping points. 

The study, published in the journal BioScience, measured some 31 planetary vital signs, ranging from coal, oil, and gas consumption to carbon dioxide emissions to ocean acidity to fossil fuel subsidies. 

The researchers compiled a set of global time series related to human actions that affect the environment and climatic responses, which include sea level change and surface temperature change. 

Out of the 31 planetary vital signs tracked, 18 were at new all-time record lows or highs. 

“There is growing evidence we are getting close to or have already gone beyond tipping points associated with important parts of the Earth system,” said Dr William Ripple, Professor of Ecology at Oregon State University and co-author of the study, in a statement.

In the past two years, there has been an unprecedented surge in climate-related disasters, with extreme flooding in South America, Southeast Asia, and Europe, record-breaking heatwaves and wildfires in Australia and western US, and devastating cyclones in Africa, South Asia, and the Western Pacific.

According to the study’s authors, governments have consistently failed to address the “overexploitation of the Earth,” which is the root cause of the current crisis.

Trends in potential drivers of climate change

Carbon dioxide, methane, and nitrous oxide all set new year-to-date records for atmospheric concentrations in 2020 and 2021. In April 2021, carbon dioxide concentrations reached 416 parts per million, the highest monthly global average concentration ever recorded. 

In addition, the year 2020 was the second hottest year on record. The top five warmest years have all occurred since 2015. 

The study also found that glacier thickness set a new all-time low in 2020 and minimum Arctic sea ice was at its second smallest extent on record. Glaciers are currently losing 31% more snow and ice per year compared to 15 years ago. 

Time series of climate-related responses, which include sea level change and surface temperature change.

Ocean pH reached its second-lowest yearly average value on record, threatening marine life with increased acidification. The ocean absorbs approximately 30% of the carbon dioxide that is released in the atmosphere, which has far-reaching impacts on aquatic ecosystems, human health, and food systems. Billions of people worldwide rely on food from the ocean as their primary source of protein.

Another concerning pattern noted was that the annual forest loss rate for the Brazilian Amazon reached a 12-year high of 1.11 million hectares destroyed in 2021.

Among the numerous worrying trends, there were a few bright spots in the study’s findings.

Fossil fuel energy consumption has decreased since 2019, along with carbon dioxide emissions, and air transport, likely due to the COVID-19 pandemic. Although projections for 2021 estimate that these measures will rise again.

Solar and wind power consumption increased by 57% between 2018 and 2021.

Fossil fuel divestment increased by US$6.5 trillion between 2018 and 2020, while fossil fuel subsidies dropped to a record low of US$181 billion in 2020.

Time series of climate-related global human activities, which include fertility rate and fossil fuel subsidies.

Calls for ‘transformational system changes’

“The updated planetary vital signs we present largely reflect the consequences of unrelenting business as usual,” said Ripple. “A major lesson from COVID-19 is that even colossally decreased transportation and consumption are not nearly enough and that, instead, transformational system changes are required.”

Priorities at the national and international level must focus on enacting immediate and drastic reductions in greenhouse gas emissions, particularly methane. Methane is emitted during the production and transport of coal, natural gas, and oil and it results from livestock and agricultural practices. 

The authors call for changes in six areas:

  • eliminating fossil fuels and shifting to renewable energy sources;
  • cutting black carbon, methane, and hydrofluorocarbons;
  • restoring and protecting the Earth’s ecosystems to restore biodiversity;
  • switching to mostly plant-based diets, reducing food waste, and improving cropping practices;
  • moving from overconsumption to ecological economics and a circular economy; and
  • stabilising population growth by providing voluntary family planning and supporting education and rights for women and girls

“By halting the unsustainable exploitation of natural habitats, we can simultaneously reduce zoonotic disease transmission risks, conserve biodiversity, and protect carbon stocks,” said the study. “So long as humanity’s pressure on the Earth system continues, attempted remedies can only redistribute this pressure.”

“Given the impacts we are seeing at roughly 1.25°C warming, combined with the many reinforcing feedback loops and potential tipping points, massive-scale climate action is urgently needed,” said the study. 

The world may have already lost the opportunity to limit warming to 1.5°C, a goal set out in the Paris Agreement, said the authors.

In the context of the major upcoming climate conference – the 26th UN Climate Change Conference of the Parties (COP26) – the authors recommend a three-pronged approach at the international level.

First, the world needs the global implementation of a significant carbon price, secondly, there needs to be a global phase-out and eventual permanent ban of fossil fuels, and the third intervention is the development of climate reserves to protect and restore natural carbon sinks and biodiversity, said the authors. 

“Implementing these three policies soon will help ensure the long-term sustainability of human civilization and give future generations the opportunity to thrive,” said the study. The study was a follow-up to one published in 2020, which nearly 14,000 scientists have signed across 153 countries, calling for urgent action to tackle the climate emergency.

Image Credits: UNDP, BioScience.

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