Climate science at a glance: why transitioning away from fossil fuels is necessary

The physics

Climate change is driven by the accumulation of greenhouse gases in the atmosphere.

Carbon dioxide (CO₂) is the main driver — and fossil fuels are the primary source.

Fossil fuels are responsible for around 86% of CO₂ emissions in the last decade, therefore, in order to limit warming to 1.5°C, fossil fuel production must decline rapidly. The climate system responds to cumulative emissions — not annual targets alone.
Every additional tonne of CO₂ adds to warming.

The carbon ‘budget’

The “+1.5°C” temperature goal was agreed by nearly all countries in the 2015 Paris Agreement, adopted under the UN Framework Convention on Climate Change (UNFCCC) — the global treaty framework that governs international climate cooperation.

To have a reasonable chance of limiting warming to 1.5°C:

  • A large share of known fossil fuel reserves must remain unextracted.

  • Existing infrastructure already risks exceeding the remaining carbon budget.

Governments are currently planning to produce more fossil fuels than is compatible with 1.5°C. This is the “production gap.”

Why demand reduction alone is not enough

Climate policy has focused mostly on reducing emissions (demand-side).

But:

  • If supply continues expanding, prices fall.

  • Lower prices stimulate consumption.

  • Infrastructure lock-in makes transition harder.

Managing fossil fuel supply is therefore essential.

Why urgency matters

Climate impacts are already visible: extreme heat, droughts and floods, food insecurity, population displacements…  And whereas achieving the 1.5° goal sounds more and more unrealistic in the current energy system, the difference between 1.5°C and 2°C means more extreme weather, greater ecosystemic collapse, and eventually iIncreased irreversible damage as such effects are cumulative and exponential. 

The window for action is narrow.

Core scientific conclusion

To stabilize the climate, there is no other way than :

  • Giving up on new fossil fuel expansion.

  • Rapid and managed phase-out of existing production.

  • a massive deployment of renewable energy.

  • Deep systemic transformation.

The science is clear. The response is political.