Can a dangerous environmental tipping point be avoided? – DW – October 25, 2023

·

·


A new report from the United Nations University Institute for Environment and Human Security (UNU-EHS) predicts that once the Earth’s destroyed ecosystems go beyond the point of return, there will be “irreversible and catastrophic consequences for humans and the planet.” ‘ is just around the corner.

The six tipping points outlined in the Interrelated Disaster Risks Report 2023 include freshwater groundwater runoff that will negatively impact food production and human survival in a warming world. and the loss of keystone species, which can cause ecosystem collapse.

“As we approach these tipping points, we are already starting to experience their effects. Once we cross them, it will be difficult to go back,” said Jack O’Connor, lead author and senior expert at UNU-EHS. warned.

Humans have brought the planet to these tipping points, but we also have a solution.

For example, rapidly reducing global warming emissions, primarily caused by the combustion of fossil fuels, will be essential to combating “unbearable heat”, which is also associated with melting glaciers and depleting groundwater.

The report’s authors say large-scale transformation is needed to reduce the risk of climate, food and water systems tipping beyond the point of recovery.

Accelerating extinction

Land use change, overexploitation, climate change, pollution and the introduction of invasive alien species are all accelerating the extinction of plants and animals at least 10 to 100 times the Earth’s natural rate, the UNU EHS report says. Pointed out.

“We are increasing the risk of co-extinction, or extinction of species that are strongly interconnected,” said Zita Sevesvary, lead author of the report and deputy director of the United Nations University Institute of Environmental Sciences.

One example is the gopher tortoise. Gopher tortoises dig burrows that more than 350 other species use for shelter, breeding, feeding, protection from predators, and avoidance of extreme temperatures.

Up to 10% of species could become extinct by the middle of this century, and up to 27% by 2100, Sevesvary told DW.

“We need to rethink conservation,” she said of possible solutions. The goal is not to target individual species at risk of extinction, but to “protect connectivity” – to stop land clearing and habitat loss, which are the root causes of extinction.

How climate change kills species

This browser does not support the video element.

groundwater depletion

Groundwater is the largest reservoir of fresh water on Earth, other than mountain glaciers, and is critical in times of overuse and water scarcity associated with global warming.

According to researchers, groundwater is stored in underground reservoirs called aquifers and provides drinking water to more than 2 billion people.

Because groundwater accumulates over thousands of years, more than half of the world’s major aquifers are being depleted faster than they can be naturally replenished. Approximately 70% of the water is drained for agricultural use.

Geeta Sebesvari said that in the arid Punjab region of northwestern India, for example, the once-thriving rice crop is overly dependent on groundwater. Now, aquifers are being depleted, and so are critical food sources for the world’s most populous country.

The solution, Sebesvary explains, is a more holistic approach to rice cultivation that involves cultivating adjacent wetlands to help supply water to water systems. Farmers ultimately need to put out less than they take in, she says.

Punjab is one of India’s largest rice-producing regions, but the crop is heavily dependent on rapidly dwindling groundwater. Image: Raminder Pal Singh/AA/Photo Alliance

melting mountain glacier

Research shows that glaciers are retreating twice as fast as they were 20 years ago.

Meltwater from glaciers and snow is an important source of fresh water for drinking, irrigation, hydropower generation, and ecosystems.

But if this melt accelerates, humanity is at risk of reaching a tipping point of “peak water,” after which water supplies slow as glaciers dry.

Small glaciers in central Europe, western Canada, and South America have already reached their peak flows or are expected to reach their peak flows within the next decade.

In the Andes, many glaciers have passed their peak flow, leaving communities with unstable supplies of drinking and irrigation water. An estimated 90,000 glaciers in the Himalayas and adjacent mountain ranges such as the Karakoram and Hindu Kush are at risk of reaching peak water levels by 2050, affecting 870 million people.

Adaptation is possible, but emergency measures to reduce greenhouse gas emissions and limit temperature rise are the only real solutions.

France’s Grasse Cave: a lost sight

Every year, many tourists flock to the Mer de Glace in Chamonix, France, especially its famous ice caves. But now, with the glaciers receding, this attraction is in danger of disappearing.

Image: Olivier Chassignol/AFP

The Mer de Glace (Sea of ​​Ice) is the largest glacier in France and the fourth largest glacier in the Alps. At the foot of Mont Blanc is the popular ski area of ​​Chamonix, from which tourists can head to a very special tourist attraction: the man-made ice cave Grote de Glace.

Image: David Ademas / Ouest-France/Maxppp/picture Alliance

splash of color in a gray landscape

The old, bright red cog railway, the Montanvers Railway, lumbers its way up 900 meters (2,900 feet) from Chamonix to Montanvers. Natural glacial caves existed as early as the early 19th century and were considered a tourist attraction even back then. However, this disappeared due to the retreat of the glaciers, and the first artificial cave was dug in 1863.

Image: Bildagentur-online/Fischer/Photo Alliance

Tourists descend nearly 500 steps to the entrance to the ice cave. In just over a century, the Mer de Grasse has lost more than a quarter of its diameter and retreated about 2 kilometers (1.3 miles). This is a result of global warming that is visible to the naked eye. Every year you have to add new steps.

Image: Philippe Desmazes/AFP

Moon landscape instead of snow and ice

Tourists crossing a footbridge attached to a rock. The ice cave can be accessed by a short hiking trail or by cable car. But imagine a sea of ​​ice and snow on the Mer de Glace River and you’ll be disappointed. The sun is burning and the sound of water dripping from the constant melting process can be heard everywhere. In many places where once everything was covered with ice, now only barren rock can be seen.

Image: Olivier Chassignol/AFP

View into the blue tunnel of the ice cave. The glacier is melting, moving 70 meters (230 feet) every year, so the cave has to be completely renewed every summer. Researchers estimate that by 2100, only about 5% of the ice in the Alps will likely remain.

Image: Sachelle Babbar/Zumapress/Photo Alliance

Inside the ice cave, visitors are exposed to breathtaking light and sound effects. But you can also admire photographs depicting life in the mountains at the beginning of the 19th century.

Image: Pascal Desroches/Godon/Photography Alliance

Tourists sit on thrones made of ice. Grote de Glace is also France’s only glacier museum, so you can also see artistic ice sculptures here. Sculptures and chairs are made using unusual tools such as saws, irons, and curling irons.

Image: Olivier Chassignol/AFP

say goodbye to the glacier

Tourists can look down on the valley from the ramp in front of the cave entrance. Scientists fear that the glaciers can no longer be saved and may disappear completely in the future. There will also be less and less white ice surface to reflect sunlight, leading to further global warming. The future at Mer de Glace will likely be rocky, gray, and possibly hot.

Image: Olivier Chassignol/AFP

unbearable heat

Directly linked to the melting of glaciers due to climate change is an increase in extreme heat, which has caused an average of 500,000 excess deaths per year over the past 20 years.

According to the report, high humidity prevents sweat from evaporating and limits the body’s natural cooling mechanisms, making heat intolerable.

When the “wet bulb” temperature (combined temperature and humidity) exceeds 35 °C (95 °F) for more than 6 hours, the body is unable to cool itself down, which can lead to organ failure and brain damage.

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

Approximately 30% of the world’s population is already exposed to deadly climatic conditions for at least 20 days a year, and this number is likely to increase to more than 70% by 2100.

While reducing greenhouse gas emissions is the ultimate solution to this problem, it is already too late in many parts of the world where this tipping point is rapidly approaching.

Relocating communities from unbearably hot areas is one solution, but relocation is not an option available to everyone. Here, adaptation measures such as the installation of sunshades and coolers need to be introduced quickly.

In Senegal’s Matam, intense heat is increasing demand for scarce water.Matam was consistently the hottest place on earth at around 48 degrees Celsius in 2023Image: John Wessels/AFP

space debris

Space satellite infrastructure is essential for surveillance and disaster risk management, explains Zita Sevesvari, author of the report.

“We need space infrastructure, for example, not only to monitor the effects of climate change, but also to monitor hazards like cyclones,” she told DW.

But with so much debris gathering in space, a chain reaction of collisions could cripple surveillance infrastructure.

Currently, only about 25% of the approximately 35,000 objects tracked in orbit are operational satellites. The rest is junk and broken satellites collected since the 1960s.

With more than 100,000 new spacecraft launched into orbit by 2030, risks will increase significantly.

“The problem is that satellites are not planned with end-of-life in mind,” she said, adding that the misconception that they can be dumped into the vastness of space and have no impact must change. Ta.

Garbage collection in outer space

This browser does not support the video element.

An uninsured future

Damage from weather disasters has increased seven times since the 1970s.

In 2022, such events caused economic losses of $313 billion (€295 billion) globally. The number of climate disasters is projected to double by 2040, according to a United Nations University-EHS report. Part of the reason is because climate change is increasing the range of wildfires, floods, and storms.

As a result of the increased risk of extreme weather events, insurance premiums have increased by 57% since 2015, with some companies canceling policies or exiting the market in high-risk areas.

The report says more than half a million homes in Australia will become uninsurable by 2030 due to rising flood risk. Those who cannot afford to move to safer areas will have to live with this risk.

Zita Sebesvari says short-term economic concerns are holding back solutions. Companies, for example, are reluctant to insure “prescribed” burning, which greatly reduces the impact of wildfires, for fear of damage to property in the event of a wildfire outbreak.

But governments and the private sector need to come together to build “future-proof” communities, based on “the rights of future generations” rather than profits, the authors say.

Editor: Jennifer Collins



Source link



Leave a Reply

Your email address will not be published. Required fields are marked *