Environment. Global warming: The goal of staying below 2°C “Is dead,” Says leading climate scientist
Renowned climate scientist James Hansen, former head of climate research at NASA, has issued a stark warning: the goal of limiting global temperature rise to below 2°C—as set by the Paris Climate Agreement—is now out of reach.
Hansen, along with a team of 18 researchers, recently published a study revealing that key climate change drivers are critically underestimated. Presenting their findings, Hansen bluntly stated:
Why Is the 2°C Goal No Longer Feasible?
One of the most optimistic scenarios from the Intergovernmental Panel on Climate Change (IPCC) suggested that drastic reductions in greenhouse gas emissions could keep global warming below 2°C. However, Hansen argues that this is now impossible due to:
Rising global energy consumption, much of which is still powered by fossil fuels.
The slow pace of the energy transition, which is failing to keep up with the urgency of climate change.
Miscalculations in climate models, which underestimate the true impact of greenhouse gas emissions.
Overlooked Factors Accelerating Climate Change
The study highlights a key regulatory change in 2020 that has been largely ignored in climate projections:
New maritime regulations reduced sulfur emissions—which, while beneficial for air quality, also removed a cooling effect that helped reflect sunlight back into space. This has accelerated warming beyond expectations.
Additionally, Hansen’s team warns that the Atlantic Meridional Overturning Circulation (AMOC)—a crucial ocean current system regulating global climate—is on track to collapse within 20 to 30 years due to ice melt. This would trigger:
Rapid sea level rise by several meters
More extreme weather patterns globally
A potential point of no return for climate stability
What’s Next?
According to the study’s projections:Global temperatures will remain at or above +1.5°C compared to pre-industrial levels in the coming years.
The 2°C threshold will likely be breached by 2045.
The Paris Agreement, signed nearly a decade ago, aimed to cap global warming below 2°C, with an aspirational target of 1.5°C. However, with the world already experiencing a 1.3°C increase, that lower limit has already been exceeded in recent years, according to the World Meteorological Organization (WMO).
