Net zero goal is key to Earth's stability: study August 3, 2024
- Ana Cunha-Busch
- Aug 2, 2024
- 3 min read
By AFP - Agence France Presse
Net zero goal is key to Earth's stability: study
Chloé FARAND
Bringing planet-warming gas emissions to net zero by 2100 is key to preventing the triggering of “tipping points” that could destabilize the systems that keep the Earth in balance, a new study said Thursday.
If left unchecked, global warming could trigger dangerous and irreversible changes in planetary systems, such as the disappearance of ice sheets or the collapse of ocean currents.
The researchers said that today's action would influence the chances of triggering these catastrophic events, even though they are very slow and will probably develop over tens to thousands of years.
“What we do now is important for the next decades, centuries, and even millennia to come,” said Nico Wunderling, one of the study's authors, from the Potsdam Institute for Climate Impact Research in Germany.
Currently, global action on climate change is insufficient to avoid the risk of at least one of the Earth's critical systems collapsing.
Global warming is on course to exceed 1.5 degrees Celsius above pre-industrial times - the limit that scientists say must be respected to avoid the most disastrous impacts of climate change.
“Permanently exceeding this limit would substantially increase the probability of triggering elements of climate disruption,” said the study in Nature Communications.
- Unacceptable risk
Under the 2015 Paris climate agreement, almost 200 countries committed to keeping warming “well below” 2°C and striving to reach the safer target of 1.5°C by the end of the century.
The world is not on track to achieve this goal.
According to UN estimates, even if countries fully comply with their existing climate plans, the world is on track for 2.5 to 2.9°C of warming this century.
The researchers wanted to assess the impact that global warming above 1.5°C could have on the “tipping points” and chose to analyze four of the Earth's main climate systems for this study.
These are: the disappearance of the Amazon's primary forest; the collapse of the Atlantic Ocean's circulation pattern; and the melting of the Greenland and West Antarctic ice sheets.
They found that for every additional 0.1°C of warming above the 1.5°C target, the likelihood increases that one or more of these four systems will suffer irreversible changes by 2300.
The trend “accelerates strongly” if warming exceeds 2C.
This is an “unacceptable risk for our climate system”, Wunderling told AFP.
This underscores the importance of the Paris climate goals “even in the case of a temporary overshoot above 1.5°C”, the study said.
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However, even if the world exceeds the 1.5°C temperature target, this risk can be reduced if “warming is rapidly reversed” this century, according to the researchers.
“The most important thing now is to keep global warming levels as low as possible above 1.5°C and return to 1.5°C as quickly as possible, ideally by mid-century and at the latest by 2100,” said Wunderling.
The researchers said their findings “underscore that stringent emission reductions in the current decade are essential for planetary stability”.
“This reversal of global warming can only be achieved if greenhouse gas emissions reach at least zero by 2100,” said Wunderling.
The study concluded that “achieving and maintaining at least zero net greenhouse gas emissions by 2100 is paramount to minimizing the risk of tipping over in the long term.”
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