Climate Change

World on brink of 6 interconnected risk tipping points: UN report

Human activities driving risk tipping points like extinctions, depleting groundwater, melting glaciers, space debris, unbearable heat and uninsurable future

By Rohini Krishnamurthy
Published: Thursday 26 October 2023
The disappearance of one species can trigger the extinction of other dependent species, leading to a ripple effect on the already fragile ecosystem, the UN report said. For example, If the gopher tortoise goes extinct, the dusky gopher frog will likely follow, affecting the entire forest ecosystem. Photo: iStock_

The world is inching closer to six interconnected risk tipping points, describing immediate and increasing risks across the world, according to a new report from the United Nations University – Institute for Environment and Human Security (UNU-EHS).

The six risk tipping points include extinctions, depleting groundwater, melting mountain glaciers, space debris, unbearable heat and an uninsurable future.

A risk tipping point is the moment at which a given socio-ecological system can no longer buffer risks and provide its expected functions, the report defined. After this point, the risk of catastrophic impacts to these systems increases substantially.

Read more: Glaciers in the Alps are melting faster than ever — and 2022 was their worst summer yet

“As we approach these tipping points, we will already begin to experience the impacts. Once crossed, it will be difficult to go back,” Jack O’Connor, lead author and senior expert at UNU-EHS said in a statement.

The report, he added, explained the risks and illustrated the driving forces and the urgent steps that need to be taken to avoid them.

Extinctions have been part of Earth’s natural process, but human activities such as land-use change, overexploitation, climate change, pollution and introduction of invasive species have accelerated extinctions.

For example, more than 400 vertebrate species have been wiped out in the last 100 years and a million plant and animal species are at risk of being extinct. Along with this, some 32 million hectares of primary or recovering forest were lost between 2010 and 2015.

The disappearance of one species can trigger the extinction of other dependent species, leading to a ripple effect on the already fragile ecosystem, the report also highlighted.

The gopher tortoise, for example, is facing an extinction risk. It is known to dig burrows that are used by more than 350 other species, including the critically endangered dusky gopher frog. These frogs help control insect populations and prevent pest outbreaks in longleaf pine forest ponds.

If the gopher tortoise goes extinct, the dusky gopher frog will likely follow, affecting the entire forest ecosystem, the UN findings stated.

Read more: Antarctic ice melting at a rate that led to the end of last ice age: Study

Further, the aquifers that store groundwater are in a critical state and two billion people rely on them as a primary source of freshwater.  Also, 70 per cent of the water is used for agriculture. Some 21 of 37 world’s largest aquifers are depleting faster than they can be replenished.

The issue is that the water stored in aquifers took more than thousands of years to accumulate and recharging them would equally take the same time, making it essentially a non-renewable resource.

In India, 78 per cent of wells in Punjab have been labelled overexploited, and the north-western part of the country is predicted to experience critically low groundwater availability by 2025.

The other system approaching the tipping point is the melting glaciers, which act as water sources for drinking, irrigation, hydropower and ecosystems.

Due to global warming, the world’s glaciers are melting at double the speed relative to the past two decades, which puts 1.9 billion people at risk. Between 2000 and 2019, glaciers lost 267 gigatons of ice per year, roughly equivalent to the mass of 46,500 Great Pyramids of Giza, the report noted.

In a warming world, we are projected to lose around 50 per cent of glaciers (excluding Greenland and Antarctica) by 2100, even if global warming can be limited to 1.5 degrees Celsius. 

Read more: Why cities are hiring dedicated officials to prepare for extreme heat

Space debris consisting of objects such as minuscule flecks of paint and massive chunks of metal has also been flagged by the report.

Out of 34,260 objects orbiting Earth, only around 25 per cent are working satellites, while the rest are junk, such as broken satellites or discarded rocket stages. Further, it is estimated that there are around 130 million pieces of debris measuring between 1 millimetre and 1 centimetre, which are too small to be tracked. 

As these objects travel over 25,000 kilometres per hour, the smallest debris can cause significant damage, including collisions between functional satellites, the report warned.

The “unbearable heat” tipping point deals with “wet-bulb temperature” above 35°C. It combines temperature and humidity. High humidity, according to researchers, hinders the evaporation of sweat and worsens the effects of heat, causing organ failure and brain damage.

Extreme weather events around the world, which have become more frequent and severe, have driven up the cost of the damage, complicating the delivery of insurance. Since the 1970s, damages wrought by weather-related disasters have increased sevenfold, with 2022 alone seeing $313 billion in global economic losses, the report highlighted.

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