Cause and Effect | Is the world on the brink of multiple tipping points? - Hindustan Times
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Cause and Effect | Is the world on the brink of multiple tipping points?

ByTannu Jain
Mar 25, 2023 07:53 PM IST

Tipping points are conditions or thresholds beyond which changes in the climate system become self-perpetuating and can lead to abrupt and irreversible impacts.

A world with about a third of Mumbai underwater.

Steam rises from the coal-fired power plant near wind turbines Niederaussem, Germany, as the sun rises on Wednesday, Nov. 2, 2022. Germany cut its greenhouse gas emissions by almost 2% last year, beating previous estimates but still falling far short of the cuts needed to meet its medium-term climate goals. (AP Photo) PREMIUM
Steam rises from the coal-fired power plant near wind turbines Niederaussem, Germany, as the sun rises on Wednesday, Nov. 2, 2022. Germany cut its greenhouse gas emissions by almost 2% last year, beating previous estimates but still falling far short of the cuts needed to meet its medium-term climate goals. (AP Photo)

The villages of London battered by unrelenting storms.

Vegetation flourishing in the sweltering heat of the Arctic.

No more New York or Miami.

The Amazon rainforest turned into a savanna. 

Are these sub-plots for apocalyptic novels? Or a potential new normal in a world driven to the brink of multiple tipping points?

Tipping points are conditions or thresholds beyond which changes in the climate system become self-perpetuating and can lead to abrupt and irreversible impacts.

Over the years, scientists have identified 16 tipping points that would take effect on timescales varying from a few years to centuries.

Last year, a study suggested that humanity may have already passed five of these tipping points. In the study, Exceeding 1.5°C global warming could trigger multiple climate tipping points, published in the journal Science in September, researchers said that even a warming of 1°C puts us at risk by triggering some of these tipping points.

The world has already warmed to 1.1°C, at the last count (2011-2020), above pre-industrial levels.

The five tipping points include: One, the collapse of Greenland’s ice cap leading to a minimum 10.6-inch (269.24 mm) sea level rise; two, the collapse of a key current in the north Atlantic Ocean that could result in more storms battering the United Kingdom; three, more intense winters and an increase in damaging heatwaves and droughts across Europe; and four, an abrupt thawing of the Arctic permafrost that would trigger a faster temperature rise by releasing vast quantities of heat-trapping greenhouse gases.

To better understand this domino effect, here is an example: If the temperature was to rise unabated, it would lead to the irreversible retreat of ice sheets, causing a disintegration of the Greenland ice sheet. This, in turn, could lead to a sea level rise of up to 7m, submerging many cities along the coasts.

According to the study, six tipping points become likely (with a further four possible) within the Paris Agreement range of 1.5-2° C rise (see figure below). These include changes in the West African monsoon patterns, the dieback of the Amazon rainforest, and the die-off of low-altitude coral reefs. The study also added that an additional climate tipping point becomes likely, and three more become possible at a warming of 2.6°C, which is expected under the current policies.

The location of climate tipping elements in the cryosphere (blue), biosphere (green), ocean/atmosphere (orange), and global warming levels at which their tipping points will likely be triggered. (Source: Science)
The location of climate tipping elements in the cryosphere (blue), biosphere (green), ocean/atmosphere (orange), and global warming levels at which their tipping points will likely be triggered. (Source: Science)
*Pins are coloured according to our central global warming threshold estimate being below 2°C, i.e., within the Paris Agreement range (light orange, circles); between 2 and 4°C, i.e., accessible with current policies (orange, diamonds); and 4°C and above (red, triangles).*

Deforestation and hotter, drier conditions would lead to the Amazon Rainforest dieback, which would further cause biodiversity loss and a decrease in rainfall, turning the rainforest into a savanna.

The Intergovernmental Panel on Climate Change (IPCC)’s Synthesis Report, released on March 20, said that with the existing policies and promises, the world is on course to overshoot the 1.5°C temperature limit agreed upon in the Paris Agreement, Conference of the Parties (COP21).

These scenarios should prompt, if not force, major emitters to cut fuel use and focus on limiting warming to well below 2° C. On the contrary, however, the fossil fuel industry’s expansion plans involve the start of oil and gas projects that will produce greenhouse gases equivalent to a decade of CO2 emissions from China, an economy that holds the not-so-coveted title of being the world’s biggest polluter, an investigation by The Guardian in May last year showed.

These plans included, what The Guardian called, 195 “carbon bombs” — gigantic oil and gas projects that would each result in at least a billion tonnes of CO2 emissions over the projects' duration. The report said about 60% of these had already started pumping in May. 

The United States, Canada and Australia are among the countries with the biggest expansion plans, The Guardian report said.

In a similar investigation in March this year, The Guardian revealed that more than 1,000 “super-emitter” sites gushed methane into the atmosphere in 2022.

Additionally, 55 “methane bombs” — fossil fuel extraction sites where gas leaks could release levels of methane equivalent to 30 years of all US greenhouse gas emissions — were found across the globe.

Methane, the much-less-talked-about-but-no-less-present greenhouse gas, can trap 80 times more heat than carbon dioxide.

Faced with these revelations, the promise by countries at COP27 in November 2022 to strengthen commitments to keep the temperature increase to 1.5C appears too little too late.

Beyond the conferences and high-level summits, climate action is more urgent than ever before. And as we inch closer to a point of no return, one can't help but recall if Greta Thunberg was right when she slammed world leaders on climate rhetoric when she said, “Blah blah blah!”

Greta Thunberg, in a speech to the Youth4Climate summit in Milan, Italy, in September 2021, hit out at global leaders over their promises to address the climate emergency, dismissing them as "Build back better, blah, blah, blah. Green economy, blah, blah, blah." (Source: Giphy)
Greta Thunberg, in a speech to the Youth4Climate summit in Milan, Italy, in September 2021, hit out at global leaders over their promises to address the climate emergency, dismissing them as "Build back better, blah, blah, blah. Green economy, blah, blah, blah." (Source: Giphy)
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  • ABOUT THE AUTHOR
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    Tannu Jain works with HT's Page 1 team. She writes on the environment and climate change, with a focus on implications at the local and global levels. She is also the author of Cause and Effect, a weekly column for HT Premium.

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