World on brink of tipping points that could be catastrophic for humanity

Humanity is headed towards a series of environmental "risk tipping points" that could cause drastic and irreversible damage if they are not addressed, the United Nations warned on Wednesday.

Meltwater from mountain glaciers is a vital water source, but supply from many glaciers is in decline because they have already reached “peak water”, when they provide the maximum amount of water run-off. AFP - FABRICE COFFRINI

Tipping points are the moments at which natural systems, including those governing our food and water supples, and technological systems are either destroyed or permanently altered.

Those at risk are inherently interconnected and closely linked to human activities and livelihoods. They are triggered by small increases in their driving force, but rapidly cause large impacts.

Climate change and the overuse of resources have put the world on the brink of six interconnected tipping points that "could trigger abrupt changes in our life-sustaining systems and shake the foundation of societies", a report Interconnected Disaster Risks, found.

Published by the UN University's Institute for Environment and Human Security in Germany, the report identified accelerating rates of extinction, groundwater depletion, melting of mountain glaciers, space debris, extreme heat and unaffordable insurance as the major interconnected threats.

"Once these thresholds are passed, the system fails to function as it normally would, and you get new risks cascading out, and these new risks can transfer to other systems," lead author Jack O'Connor warned.

"We should be expecting these things to happen because in certain areas they are happening already."

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The six risk tipping points

1. Extinction

The report warned that a million plants and animals could be wiped out "within decades", with the loss of key species to raising the likelihood of ecosystem collapse

2. Groundwater depletion

 Many people rely on underground water reservoirs for drinking and agriculture. If this groundwater is depleted quicker than it is naturally replenished, and the water table falls below a level that existing wells can access, food production could then be seriously affected.

3. Glacial melt

Meltwater from mountain glaciers is also a vital water source. Once glaciers reach “peak water”, when they provide the maximum amount of water run-off, the supply will slowly decline. This threshold has already been passed in many glaciers around the world.

4. Space debris

Collisions of space debris were set to render the Earth's orbit "unusable", the report warned, and make future space activity – including satellite monitoring of environmental threats – impossible.

5. Unbearable heat

Climate change is causing a global rise in temperatures that has seen 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.

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

6. Unaffordable insurance

 Worsening climate hazards are now making insurance unaffordable, with half a million homes in Australia alone set to be uninsurable by 2030, the researchers said.

The report’s publication comes ahead of Cop28 climate talks next month.