Net zero by 2025 is not physically impossible. There is no real barrier to deploying the technology required or to achieving the necessary changes in behaviour. But to achieve this, it is not a question of physical possibility but rather whether you believe it is possible to change the economic structure and political decision making of the UK (and EU and world) overnight to allow us to deploy all possible solutions over the next five years.

The road from the geosciences to climate policy is long and winding. However, carbon budgets provide one of the simplest and most transparent means of connecting geophysical limits imposed by the Earth system to implications for climate policy.

Netto-Null-Ziel müsste also hier schon Ende 2028 oder sogar Ende 2025 erreicht werden. Das entspricht der Forderung der noch recht jungen Umweltbewegung Extinction Rebellion, die im Frühjahr durch spektakuläre Straßenblockaden in London weltweit bekannt geworden ist. „Wenn man 1,5 Grad mit einer Zwei-Drittel-Wahrscheinlichkeit erreichen will und die Feedbackmechanismen des Erdsystems und die größere Verantwortung von Industrieländern berücksichtigt, dann ist das die logische Konsequenz“, sagt Klimaforscher Rogelj.

Our work clearly demonstrates that we already have the tools and technology needed to efficiently power the UK with 100% renewable energy, to feed ourselves sustainably and so to play our part in leaving a safe and habitable climate for our children and future generations.