Highest Possible Ambition

How can we limit overshoot above 1.5ºC?

Climate Analytics’ new global scenario provides a route to get temperatures back below 1.5ºC before 2100.

Global energy and emissions scenarios have been a critical line of evidence to help inform what highest possible ambition could entail. However, the 1.5°C-aligned pathways assessed in the most recent IPCC cycle (AR6) are becoming increasingly outdated. Since their creation around five years ago, the world has failed to cut emissions, sending global temperatures racing towards the 1.5°C limit. On the other hand, every year the cost of renewable energy and other zero-carbon technologies are falling rapidly and their deployment is accelerating.

Our new Highest Possible Ambition (HPA) scenario updates these pathways to address these issues. It accounts for the failure to cut global emissions sufficiently over 2020–25, but also the emerging new realities around the game-changing potential for renewables and electrification to achieve the safest possible temperature outcome within physical, technological and economic feasibility limits. It provides an updated evidence base on how to achieve the Paris goal, starting from where we find ourselves in the mid-2020s.

Highest Possible Ambition scenario

Global warming can be halted in the next 15 to 20 years and return well below 1.5°C by 2100 in line with the Paris goal following a period of overshoot of the warming limit.

This scenario shows we can still return to safe levels warming if we act with the highest possible ambition, starting now. This analysis updates IPCC AR6 pathways to reflect today’s higher starting emissions and sets out what is needed to limit overshoot above 1.5ºC, and to get temperatures back well below 1.5ºC before 2100. Under this new scenario, global warming would peak near ~1.7°C and fall to ~1.2°C by 2100, CO₂ would reach net zero before 2050 with all GHGs in the 2060s, electrification would supply nearly two-thirds of energy by mid-century, a rapid fossil-fuel phaseout would be paired with strong methane cuts, and carbon removal would scale quickly.

Levers to achieve highest possible ambition

For details on our previous analysis using pathways from the IPCC's Sixth Assessment Report, click here.