5 of 9 Tipping Point Thresholds Already Surpassed
A new study has found that exceeding 1.5 degrees C of global warming could trigger disastrous climate tipping points -- which become accelerated at certain thresholds and have serious implications for human habitability and resources. Currently, the world has warmed 1.1 degrees C, which means five of the nine critical tipping points pointed to in the study may have already surpassed their thresholds. These include the melting of Greenland’s ice cap, the collapse of the Atlantic Meridional Overturning Circulation (AMOC) -- an important Gulf Stream current, and the destabilization of the Amazon rainforest.
The idea of tipping points was introduced over 20 years ago by the IPCC, and according to 2019 article in Nature:
If current national pledges to reduce greenhouse-gas emissions are implemented -- and that’s a big ‘if’ -- they are likely to result in at least 3 degrees C of global warming … The stability and resilience of our planet is in peril. International action -- not just words -- must reflect this.
PBS: What Will Earth Look Like When These 6 Tipping Points Hit?, September 6, 2022.
KING 5: The Tipping Point | Climate change factors threatening the PNW, May 19, 2022.
BBC: Past seven years hottest on record, EU satellite data shows, January 10, 2022.
Why This Matters
A risk analysis conducted at the Potsdam Institute for Climate Impact Research (PIK) in Germany, found that climatic events on the brink of a tipping point can destabilize one another and create a domino effect that could lead to a runaway greenhouse effect. In this scenario, Earth would continue to warm even with a complete halt to human-caused carbon emissions.
As of now, excess carbon emissions and the world’s dependence on fossil fuels aren’t waning to the scale and speed necessary. As a result, the earth continues warming and creeping towards critical tipping point thresholds. The window for prevention is closing, and when it does, there will be “irreversible changes and cascades” to the planet’s complex climate system, making it harder to “maintain liveable conditions on Earth and enable stable societies”.
Now This: Scientist Johan Rockström Explains Earth's Climate Tipping Points, October 14, 2020.
Grantham Imperial: Dr Friederike Otto speaks to BBC World News about the heatwaves, 18 July 2022, July 19, 2022.
The Economist: See what three degrees of global warming looks like, October 30, 2021.
Tipping Points for Melting: Greenland & Antarctica
Last year, a study found that Greenland’s ice cap was on the brink of a tipping point that could result in trillions of tons of ice being dumped into the ocean. Now scientists say the melting of Greenland’s ice sheet is inevitable and will cause at least 10.6 inches of sea level rise, and if emissions aren’t curbed other ice caps too will melt, possibly resulting in meters of sea level rise.
The Twaites Glacier, an Antarctic ice shelf nicknamed the “doomsday glacier” is on the brink of collapse and is predicted to melt within the next three to five years. Currently responsible for about 4% of global sea rise, accelerated melting could spell disaster for coastal communities around the US -- especially the East Coast -- already at risk of inundation.
PBS: Scientists measure how quickly crucial Antarctica glacier is melting, July 25, 2022.
PBS: Melting of the Thwaites Glacier could rewrite the global coastline, December 15, 2021.
CNN: 'Mind boggling' | See how rising sea levels will affect the coasts, February 17, 2022.
DW: Can we stop ice sheets from melting?, September 9, 2022.
Circulation Change Tipping Points: Indian Monsoon Shift & AMOC
The climate crisis continues to demonstrate its ability to devastate, especially with flooding. In Pakistan, 33 million people were impacted by cataclysmic floods from the summer’s record-breaking monsoon season, nearly 1,400 people died, and around half a million people are now without homes. The current cost of damages has reached $30 billion.
“Even today, emissions are rising as people die in floods and famines. This is insanity. This is collective suicide,” stated UN Secretary-General António Guterres. “From Pakistan, I am issuing a global appeal: Stop the madness; end the war with nature; invest in renewable energy now.”
PBS: Scale of destruction due to Pakistan floods nearly 'incomprehensible,' September 11, 2022.
DW: UN chief Guterres blames climate change for Pakistan floods, September 10, 2022.
The AMOC is a current system in the North Atlantic Ocean that effectively mediates weather across Europe and sea levels along the US Atlantic coast. However, it has significantly weakened with global warming. Scientists now estimate the AMOC will slow by 34% to 45% by the end of the century as freshwater from melting glaciers pours into the ocean, leading to harsher winters in the UK and an increased frequency of heatwaves and droughts across Europe.
Potsdam Institute (Earth System Analysis): Is the Atlantic Overturning Circulation approaching a tipping point?, March 21, 2022.
Biome Shift Tipping Points: Amazon Rainforest Dieback
A deadly combination of deforestation and habitat degradation has pushed the Amazon to the brink of a tipping point and threatens to turn the lush rainforest into a dry savannah, cause significant biodiversity loss, and reduce the region’s carbon storage capabilities. Other concerns include the forest becoming more prone to wildfire and drought and slower to recover. Without the Amazon, the world would lose an effective carbon sink and experience an accelerated greenhouse effect and rapid global warming.
FOX 13: Amazon near tipping point of shifting from rainforest to savannah, March 15, 2022.
Sky News: COP26 | Scientists say Amazon rainforest is at 'tipping point,' November 1, 2021.
“It’s Not Game Over”
Despite underlining concerns around tipping points in this latest study, lead author Dr. David Armstrong McKay states, “[There] are also still grounds for hope … We’re not saying that, because we’re probably going to hit some tipping points, everything is lost and it’s game over. Every fraction of a degree that we stop beyond 1.5C reduces the likelihood of hitting more tipping points.”
BBC: The Tipping Point | Climate Change | The Facts, Movember 13, 2021.
CBS (Canada): Maintaining hope in the fight against climate change, July 22, 2022.
The New School: Hope in the Time of Climate Crisis, April 21, 2022.
TED: Fossil fuel companies know how to stop global warming. Why don't they? | Myles Allen, December 4, 2020.