Climate Crisis: Why Even Temporarily Overshooting 2°c Would Cause Permanent Damage

pending climate disaster3 6 29 Ondrej Prosicky/Shutterstock

The history of climate change is one of people slowly coming to terms with the truth. None but a small minority still question whether it’s real and caused by humans. Now most grapple with the reality of trying to slow down catastrophic warming, and the difference between solutions and false hope. The concept of climate overshoot is the next thing we will need to get to grips with.

Unless urgent action is taken, emissions are expected to cause the planet to continue heating rapidly over the next few decades, prompting the global average temperature to overshoot the Paris agreement’s target, which aimed to limit warming to between 1.5°C and 2°C. A period of higher temperatures will occur in the middle of this century as a result. Then, the idea goes, new but yet unproven technologies and techniques for pulling greenhouse gases from the atmosphere will eventually bring temperatures back down to a safer level.

Until now, scientists were unsure what temporarily overshooting (and then boomeranging back below) the Paris agreement’s temperature target would entail for nature. So, for the first time, we studied the consequences of allowing Earth’s temperature to exceed these precautionary limits, then fall below them again, for marine and land-based life. In other words, we looked at how damaging the journey of overshooting the 2°C temperature target would be, and not just the destination itself.

The results suggest that a temporary overshoot would cause waves of irreversible extinctions and lasting damage to tens of thousands of species. This is what the world can expect if humanity fails to make deep emission cuts this decade, and relies instead on future technologies to remove emissions later.

Harm arrives fast and leaves slowly

Our study modelled the impact of global temperatures exceeding 2°C for around 60 years between 2040 and 2100 on over 30,000 species that live on land and in the sea. We looked at how many of them would be exposed to temperatures that could hinder their reproduction and survival, and how much time they would be exposed to this risk.

pending climate disaster2 6 29 In this scenario in which the world overshoots the 2°C target, emissions do not peak until 2040. Meyer et al. (2022), Author provided

Harm would be fast to arrive and slow to disappear for nature, even after temperatures fall again. Just a few years of global temperatures above 2°C could transform the world’s most important ecosystems. Take the Amazon basin, for example. Some species would remain exposed to dangerous conditions long after the global average temperature stabilised – with some remaining exposed as late as 2300. This is because some species, especially those in the tropics, live closer to the limit of heat they can tolerate and so are sensitive to relatively small changes in temperature. And while global average temperatures may return to safer levels eventually, local temperature changes might lag behind.

The consequences of this exposure could be irreversible and include the tropical forest turning into savanna. The world would lose a critical global carbon sink, leaving more planet-warming gases in the atmosphere.

The Coral Triangle in the western Pacific Ocean is one of the most species-rich marine ecosystems and home to many reef-building corals, sea turtles, reef fish and mangrove forests. Our modelling showed that in some communities, all or most of the species would be exposed to dangerous conditions simultaneously for at least a few decades and as much as two centuries. As well as disrupting a source of food for millions of people, disappearing corals and mangroves would remove a natural barrier protecting coastal towns and villages from rising seas and worsening storms.

pending climate disaster 6 29 Tropical corals exist at the limit of their thermal tolerance and are especially vulnerable to climate change. Ethan Daniels/Shutterstock


 Get The Latest By Email

Weekly Magazine Daily Inspiration

No way home

The consequences of overshooting 2°C for the survival of species have been neglected by policymakers. Our analysis indicates that it cannot be assumed that life will simply recover once temperatures fall below 2°C again. We found that 3,953 species will have their entire population exposed to temperatures outside the range they evolved in for more than 60 consecutive years. The Philippine porcupine will be exposed for 99 years, and the Mawa clawed frog for an astonishing 157 years. Surviving this length of exposure is a stern challenge for any species.

Relying on carbon dioxide removal and so-called negative emissions technologies to lower greenhouse gases in the atmosphere over several decades is too risky to contemplate. Some of this technology, like carbon capture and storage, hasn’t yet been shown to work at the scale needed. Other techniques have negative effects on nature, such as bioenergy, where trees or crops are grown and then burned to generate electricity. Rolling out vast plantations at the same time as temperatures overshoot the internationally agreed “safe” limit would leave species reeling from a hotter climate and shrinking natural habitat.

Delaying drastic cuts to emissions will mean the world overshooting 2°C is a best-case scenario. This overshoot would come at an astronomical cost to life on Earth that negative emission technologies will not reverse. The effort to stop temperatures rising isn’t an abstract attempt at bending curves on a graph: it’s a fight for a liveable planet.

About The Author

Joanne Bentley, Postdoctoral Researcher in Molecular Ecology, African Climate & Development Initiative, University of Cape Town; Alex Pigot, Research Fellow, Genetics, Evolution & Environment Division of Biosciences, UCL; Andreas L. S. Meyer, Postdoctoral Research Fellow in Ecology & Evolutionary Biology, University of Cape Town, and Christopher Trisos, Senior Research Fellow in Climate Change Risks, University of Cape Town

This article is republished from The Conversation under a Creative Commons license. Read the original article.


Recommended Books:

Yellowstone's Wildlife in Transition

Yellowstone's Wildlife in TransitionOver thirty experts detect worrying signs of a system under strain. They identify three overriding stressors: invasive species, private-sector development of unprotected lands, and a warming climate. Their concluding recommendations will shape the twenty-first-century discussion over how to confront these challenges, not only in American parks but for conservation areas worldwide. Highly readable and fully illustrated.

For more info or to order "Yellowstone's Wildlife in Transition" on Amazon.

The Energy Glut: Climate Change and the Politics of Fatness

The Energy Glut: Climate Change and the Politics of Fatnessby Ian Roberts. Expertly tells the story of energy in society, and places 'fatness' next to climate change as manifestations of the same fundamental planetary malaise. This exciting book argues that the pulse of fossil fuel energy not only started the process of catastrophic climate change, but also propelled the average human weight distribution upwards. It offers and appraises for the reader a set of personal and political de-carbonising strategies.

For more info or to order "The Energy Glut" on Amazon.

Last Stand: Ted Turner's Quest to Save a Troubled Planet

Last Stand: Ted Turner's Quest to Save a Troubled Planet by Todd Wilkinson and Ted Turner. Entrepreneur and media mogul Ted Turner calls global warming the most dire threat facing humanity, and says that the tycoons of the future will be minted in the development of green, alternative renewable energy. Through Ted Turner's eyes, we consider another way of thinking about the environment, our obligations to help others in need, and the grave challenges threatening the survival of civilization.

For more info or to order "Last Stand: Ted Turner's Quest..." on Amazon.


follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

AVAILABLE LANGUAGES

enafarzh-CNzh-TWdanltlfifrdeeliwhihuiditjakomsnofaplptroruesswsvthtrukurvi

MOST READ

baseball player w;ith white hair
Can We Be Too Old?
by Barry Vissell
We all know the expression, "You're as old as you think or feel." Too many people give up on…
is it covid or hay fecer 8 7
Here’s How To Tell If It's Covid or Hay Fever
by Samuel J. White, and Philippe B. Wilson
With warm weather in the northern hemisphere, many people will be suffering from pollen allergies.…
climate change and flooding 7 30
Why Climate Change Is Making Flooding Worse
by Frances Davenport
Although floods are a natural occurrence, human-caused climate change is making severe flooding…
inflation around the world 8 1
Inflation Is Spiking Around The World
by Christopher Decker
The 9.1% increase in U.S. consumer prices in the 12 months ending in June 2022, the highest in four…
made to wear a mask 7 31
Will We Only Act On Public Health Advice If Someone Makes Us?
by Holly Seale, UNSW Sydney
Back in mid 2020, it was suggested mask use was similar to seat belt wearing in cars. Not everyone…
sage smudge sticks, feathers, and a dreamcatcher
Cleansing, Grounding, and Protecting: Two Foundational Practices
by MaryAnn DiMarco
Many cultures have a ritualistic cleansing practice, often done with smoke or water, to help remove…
overcoming lonliness 8 4
4 Ways To Recover From Loneliness
by Michelle H Lim
Loneliness isn’t unusual given it’s a natural human emotion. But when ignored or not effectively…
changing peoples minds 8 3
Why It’s Hard To Challenge Someone’s False Beliefs
by Lara Millman
Most people think they acquire their beliefs using a high standard of objectivity. But recent…

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.