Can dangerous environmental tipping points be averted?

"Irreversible, catastrophic impacts for people and the planet," are around the corner if ravaged global ecosystems are tipped past the point of return, says a new report by the United Nations University's Institute for Environment and Human Security (UNU-EHS).   

Six tipping points outlined in the "Interconnected Disaster Risks Report 2023" include the draining of fresh groundwater that will harm food production and human survival in a warming world; and the loss of keystone species that can trigger ecosystem collapse.   

"As we approach these tipping points, we will already begin to experience the impacts. Once crossed, it will be difficult to go back," warned Jack O'Connor, lead author and senior expert at UNU-EHS.   

Humans have pushed the planet to these tipping points but also have the solutions.

Rapidly reducing planet-heating emissions largely caused by burning fossil fuels, for example, will be vital to combating "unbearable heat" that is also related to glacial melt and groundwater depletion.  

The report authors say major transformation is required to reduce the risk of tipping climate, food and water systems beyond the point of recovery. 

Accelerating extinctions  

Land-use change, overexploitation, climate change, pollution and introduction of invasive alien species are all accelerating plant and animal extinction to at least 10 to 100 times the planet's natural rate, notes the UNU-EHS report.  

"We are increasing the risk of co-extinction, that is to say those species that are strongly interconnected," said Zita Sebesvari, report lead author and UNU-EHS deputy director.      

An example is the gopher tortoise, which digs burrows that are used by more than 350 other species for shelter, breeding, feeding, protection from predators and avoiding extreme temperatures.   

By mid-century up to 10% of species could be wiped out, and up to 27% by 2100, Sebesvari told DW.  

"We need to rethink conservation," she said of potential solutions. The goal is not to target threatened individual species but to "save connections," meaning stopping the land clearing and habitat loss at the root of extinctions.    

Groundwater depletion 

Groundwater is the largest store of freshwater on the planet outside of mountain glaciers and will be vital in an age of water scarcity linked to overuse and global heating.   

Held in underground reservoirs called aquifers, groundwater supplies drinking water to over 2 billion people, according to the researchers.  

More than half of the world's major aquifers are depleting quicker than they can be naturally replenished as groundwater accumulates over thousands of years. Around 70% is being drained for agriculture.

Zita Sebesvari said that in the dry Punjab region of northwest India, for instance, once-flourishing rice cultivation is overly reliant on groundwater. Now the aquifers are drying up, along with a vital source of food for the world's most populous country.  

The solution, explains Sebesvari, is a more holistic approach to rice farming, including nurturing adjacent wetlands that help feed water into aquifers. Farmers ultimately need to take out less than goes in, she said. 

Melting mountain glaciers  

Glaciers are retreating twice as fast as they were two decades ago, according to the study.  

Meltwater from glaciers and snow is a vital freshwater source for drinking, irrigation, hydropower and ecosystems.  

But as this melt quickens, humans are at risk of reaching the "peak water" tipping point, after which water supply slows as the glaciers dry up.  

Across smaller glaciers in Central Europe, Western Canada and South America, peak water has already been reached or is expected within the next 10 years. 

In the Andes mountains, many glaciers have passed their peak flow and communities face unreliable water supply for drinking and irrigation. An estimated 90,000 glaciers in the Himalayas and adjacent mountain ranges like the Karakorum and Hindu Kush are at risk of reaching peak water by 2050, affecting 870 million people. 

While adaptation is possible, urgent measures to limit temperature rise by cutting greenhouse gas emissions are the only real solution. 

Unbearable Heat 

Directly related to climate change-driven glacial melt is increasing extreme heat that has caused an average of 500,000 excess deaths annually in the last two decades. 

High humidity makes heat more unbearable by hindering sweat evaporation, and limiting the body's natural cooling mechanism, says the report.  

When the "wet-bulb" temperature, which combines temperature and humidity, exceeds 35 degrees Centigrade (95 degrees Fahrenheit) for more than six hours, the body's inability to cool off can result in organ failure and brain damage. 

The report pointed to research showing that by 2070, parts of South Asia and the Middle East will regularly surpass this threshold. 

With around 30% of the global population already exposed to deadly climate conditions for at least 20 days per year, this number could rise to over 70% by 2100. 

While cutting greenhouse gas emissions is the ultimate answer to the problem, it is already too late for many parts of the world where this tipping point is fast-approaching.  

Moving communities away from unbearably hot areas is one solution, but relocating is not an option available to everyone. Here adaption, including providing shade and cooler housing, needs to be quickly implemented.    

Space debris

Space satellite infrastructure is vital for monitoring and disaster risk management, explains report author, Zita Sebesvari.  

"We need space infrastructure for monitoring of, for example, climate change impacts, but also to monitor hazards like cyclones," she said. 

But so much junk is gathering in space that a chain of collisions could render monitoring infrastructure inoperable.  

Out of near 35,000 objects tracked in orbit today, only around 25% are working satellites. The rest are discarded objects or broken satellites that have gathered since the 1960s.  

With over 100,000 new spacecraft to be launched into orbit by 2030, the risk will greatly increase. 

"The problem is that satellites are not planned with end of life in mind," she said, adding that the misconception that dumping into the vastness of space will have no impact has to change.

Uninsurable future 

Weather-related disaster damage has increased seven-fold since the 1970s. 

In 2022, such events caused $313 billion (€295 billion) in global economic losses. The number of climate disasters is forecast to double by 2040, according to the UNU-EHS report. This is partly because climate change is increasing the scope of wildfires, floods and storms. 

As a result of the increasing risk of extreme weather disaster, insurance premiums have risen as much as 57% since 2015, and some companies are canceling policies or leaving the market in high-risk areas.  

The report noted that rising flood risk will make over half a million Australian homes uninsurable by 2030. Those who cannot afford to move to safer areas will have to live with this risk.   

Zita Sebesvari says that short-term economic concerns are holding back solutions. Companies won't insure "prescribed" burning — which significantly lessens wildfire impacts— for example, for fear an outbreak will damage properties. 

But governments and the private sector must come together to "future proof" communities, says the author, not on the basis of profit, but the "rights of future generations."

Edited by: Jennifer Collins