A new report released by the United Nations University has found that drastic changes are urgently needed to save socioecological systems from catastrophic threats. The report highlights that the world is approaching six risk tipping points: accelerating extinctions, groundwater depletion, mountain glacier melting, space debris, unbearable heat and an uninsurable future.
The 2023 Interconnected Disaster Risks Report, by the United Nations University – Institute for Environment and Human Security (UNU-EHS), defines a risk tipping point as “the moment at which a given socioecological system is no longer able to buffer risks and provide its expected functions, after which the risk of catastrophic impacts to these systems increases substantially.” The risk tipping points highlighted in the report show the areas that need immediate attention and action.
One example is the depletion of groundwater, which is a crucial freshwater resource stored in underground reservoirs called aquifers. These aquifers provide drinking water to over 2 billion people globally and around 70 per cent of withdrawals are used for agriculture. But, currently, more than half of the world’s major aquifers are being depleted faster than they can be replenished, the report explains. The water in the aquifers has accumulated over thousands of years and would take a similar time to fully recharge.
When the water table of an aquifer drops consistently below the well depth, access to groundwater will be an issue. This will affect, for instance, farmers' ability to irrigate their crops, directly impacting food production.
"India is the world's largest user of groundwater, exceeding the use of the United States and China combined,” the report adds. According to the Press Trust of India, some regions in the Indo-Gangetic basin in India have passed the groundwater depletion tipping point and its entire northwestern region is predicted to experience critically low groundwater availability by 2025.
Another tipping point highlighted by the report is rapidly increasing extinctions. Although extinction is part of the evolutionary process, it’s not natural for it to happen as rapidly as it is occurring now. Through over-exploitation, climate change, pollution and the introduction of invasive species, humans have accelerated the process of extinction. In the last 100 years, over 400 species have become extinct, and about one million plant and animal species are under threat, many facing extinction within decades, the report explains.
The report warns that the extinction of a species that is strongly connected to an ecosystem can lead to further extinctions of dependent species, triggering an ecosystem collapse.
The third tipping point is one that many might be familiar with: the melting of glaciers. Meltwater from glaciers and snow provides water for drinking, irrigation, hydropower and ecosystems in many regions. However, due to global warming, the world’s glaciers are melting at double the speed they had in the past two decades, the report states.
Between 2000 and 2019, glaciers lost 267 gigatons of ice per year, which is roughly equivalent to the mass of 46,500 Great Pyramids of Giza. According to the report, the world is projected to lose around 50% of glaciers (excluding Greenland and Antarctica) by 2100, even if global warming can be limited to 1.5°C. This puts almost two billion people at risk of negative effects due to glacier retreat – when the ice mass melts faster than snow can replace.
When glaciers retreat, long-term ice storage melts and is gradually released as meltwater. The volume of water released increases until a maximum limit is reached. After this tipping point, glacier meltwater volume decreases as the glacier continues to shrink, the report explains. This affects freshwater availability for humans and other species.
The fourth tipping point mentioned in the report, the increasing amount of space debris, is an important one that is not talked about enough. As technology is advancing rapidly and affordability increases, more countries are sending satellites into space. Although they are important for monitoring the weather, providing early warnings for disasters, and communication, as the number of satellites increases, so does the debris they leave behind.
The report finds that out of 34,260 objects tracked in orbit, only around 25% are working satellites while the rest are debris, such as broken satellites or discarded rocket stages. Moreover, there are likely to be about 130 million pieces of debris that are too small to be tracked, measuring between 1 mm and 1 cm. These could cause significant harm to existing satellites as well as our orbit.
When the amount of objects in orbit around Earth reach a critical point, such that one collision between two objects can set off a chain reaction, it will cause the orbit to become too dense and unusable.
The fifth tipping point is related to something that India has been struggling with: excessive heat. As human-induced climate change has caused a rise in temperature, it has led to more frequent and severe heatwaves globally. Extreme heat resulted in an average of 500,000 excess deaths annually in the last two decades. This also disproportionately affects the most vulnerable.
Currently, 35°C is the maximum wet-bulb temperature, the lowest temperature to which air can be cooled by evaporation at a constant pressure, from which humans can survive. The report states that by 2070, parts of south Asia and the middle east will regularly surpass this threshold.
Moreover, about 30% of the global population is exposed to deadly climate conditions for at least 20 days per year, and this number could increase to over 70% by 2100, the report elaborates.
Being exposed to above 35°C wet-bulb temperature for longer than six hours will lead to a healthy, young adult experiencing severe health consequences.
The final tipping point is the cost of damage from extreme environmental events. Since the 1970s, people have witnessed a seven-fold increase in the cost of disasters globally. The world has experienced $313 billion in global economic losses from disasters in just 2022. The report warns that increasingly severe hazards can significantly increase the costs of insurance until it is no longer accessible or affordable. This can leave people without an economic safety net, which will lead to extreme socio-economic effects in high-risk areas.