The world is at a historic tipping point as global warming crosses a critical threshold for the first time. 1.5 degrees Celsius. Scientists warn that this excess, technically called „"overshoot"“, it is not just temporary weather fluctuation, but a trigger for a cascade irreversible changes, which can transform the planet and destroy the stability of the ecosystems on which human civilization depends. There is a risk that once we cross certain thresholds – the so-called. turning points – there is no way back to the original state, even in the event of a later reduction in emissions.

The reality of overshoot: Why is 1.5°C a dead target?

The 1.5 degree Celsius limit was set a decade ago as part of the Paris Agreement as a target to avert the worst impacts of the climate crisis. However, according to current scientific knowledge, this target is already practically unattainable. unattainable.

• Three-year breakthrough: The first three-year period ending in 2025 officially broke this threshold.
• Record years: The years 2023 and 2025 came close to the 1.5°C limit, while the year 2024 reached 1.55 degrees of warming above pre-industrial levels.
• Policy failure: Atmospheric chemist Robert Watson says that a decade of weak action means the Paris Agreement is essentially dead.

Although the 1.5°C limit is traditionally measured as a 20-year average, two independent studies from 2025 suggest that the world has probably already passed this critical threshold. Without a radical change of course, climatologist James Hansen predicts that the limit We will reach 2°C as early as 2045.

Pincer grip: Why is warming accelerating?

The climate system is currently in a dangerous "pincer grip" that is accelerating the rise in temperatures in two directions:

1. High emissions: Greenhouse gas production remains stubbornly high.
2. Weakening natural absorbers: Natural systems, which have so far absorbed around half of our CO2 emissions, are losing their strength.

Nature stops helping Until now, trees grew faster due to heat, and the oceans buried excess carbon in their depths. But this mechanism is coming to an end. The oceans are becoming more stratified, reducing their ability to remove CO2, and trees are subject to extreme drought and heat. For example African rainforests, which once absorbed a fifth of the Earth's CO2, have recently changed from a sink to a source of emissions. In addition, the global incidence of extreme forest fires has doubled in the past two decades.

Main turning points: What are we facing?

Tipping points are thresholds beyond which previously stable systems suddenly change and cannot be „fixed.“ If the world does not get back below 1.5°C by the end of the century, there is a likelihood one to four, that we will cross at least one of the key global thresholds.

1. Melting ice sheets

Greenland is currently losing 30 million tons of ice every hour. Scientists predict that this melting could become unstoppable at 1.5°C. The complete melting of Greenland would raise the level of the world's oceans by about 7 meters. A similar fate threatens the West Antarctic Ice Sheet.

2. Ocean Current Collapse (AMOC)

The Atlantic Meridional Circulation (AMOC), which includes the Gulf Stream, distributes heat around the world. James Hansen says it could shut down in the next few years. 20 to 30 years. If the AMOC were to fail, northwestern Europe would be plunged into a period of extremely harsh and long winters.

3. The extinction of the Amazon rainforest

The predicted death of the Amazon rainforest would release billions of tons of CO2 back into the atmosphere, further intensifying warming.

4. Coral reefs

Tropical coral reefs are likely past their tipping point. They could be completely dead by mid-century, with massive consequences for marine ecosystems and fish stocks that depend on reefs as breeding and feeding grounds.

5. Permafrost and the methane bomb

Melting Arctic permafrost releases huge amounts of frozen methane, which is an extremely potent greenhouse gas. This process will play a critical role in amplifying climate change, especially in overshoot scenarios.

The domino effect: A cascade of disasters

Scientists are concerned about the so-called. domino effect, where crossing one tipping point triggers the collapse of another. One such scenario is that the melting of the Greenland ice sheet disrupts the ocean circulation (AMOC), which in turn causes the definitive collapse of the Amazon rainforest.

We are already seeing these changes in practice today:

• Economic damage: Extreme weather linked to climate change has cost the global economy more than 2 trillion dollars and affected a fifth of the world's population.
• Human lives: Deaths from heatstroke are rising sharply in India, Africa and the Middle East.
• Weather intensity: NASA data shows a dramatic increase in the intensity of global weather over the past five years.

Can we go back? The possibilities of "negative emissions"„

To stabilize the climate system after exceeding 1.5°C, it will be necessary to achieve the so-called. negative emissions – processes that pull carbon out of the atmosphere. Scientists estimate that to return to safe temperatures by 2100, we would need to remove up to 400 billion tons of CO2.

Proposed solutions and their limits:

Geoengineering is the most controversial. Robert Watson compares it to „"turning on the air conditioning in a burning house"“. While this might reduce temperatures, it would not solve the cause (greenhouse gases) and the world's weather systems would remain fundamentally disrupted.

Political passivity and an uncertain future

Despite alarming scientific data, world governments appear to be losing the will to fight emissions. The US has abandoned the joint climate effort and global efforts to reach „net zero“ by 2050 are falling far behind. It was not until 2025 that UN negotiators at a conference in Brazil officially acknowledged for the first time the need to address how to manage a temperature overshoot.

The only country that has so far set a national target for negative emissions is Denmark, which promises a reduction of 110 % by 2050.

Conclusion: Permanent overshoot or emergency brake?

We are witnessing cracks in the resilience of Earth's systems. If we do not take immediate action to not only reduce emissions but also actively remove carbon from the atmosphere, we risk overshoot will be permanent. In that case, the world will move into an era of accelerated warming that will no longer be possible to stop. Nature, which has protected us for millennia, ceases to balance our abuses, and we are approaching the point of no return. JRi&CO2AI 

Main takeaways:

• The world has probably definitely crossed the line 1.5 °C.
• Natural sinks (forests, oceans) they fail, which accelerates warming.
• Key turning points include AMOC collapse, Greenland melting and coral death.
• Technological solutions for CO2 removal are currently either too expensive, or dangerous.
• Without immediate global action, the climate system could change irreversibly and suddenly.