1.5°C still achievable – if the world pursues ‘highest possible ambition’

Scientists say it is still possible for the world to return to well below 1.5°C of warming this century despite decades of insufficient action – but only if countries drastically increase their ambition.

In a study published today (November 6), Climate Analytics and the Potsdam Institute for Climate Impact Research (PIK) offer updated climate scenarios to reflect a higher starting point for emissions reduction and lay out the steps necessary to limit overshoot and meet the 1.5ºC temperature limit set by the Paris Agreement.

The report’s ‘highest possible ambition’ scenario shows how accelerating the scale-up of renewables and electrifying the global economy can slow and then halt global warming before 2050, and limit peak warming to around 1.7ºC. After that, it should be possible to bring temperatures back down well below 1.5ºC by 2100, thanks to the rapid phase-out of fossil fuels, strong reductions in methane emissions, and scaling up carbon removal technologies.

“The last five years have cost us precious time in this critical decade of climate action. However, they have also seen a revolution in renewables and batteries, which have shattered records across the globe. Riding these tailwinds can help turbocharge our clean energy future and catch-up on lost time. The window to minimise overshoot is still open but narrowing fast. The choice is ours,” said Dr Neil Grant, Senior Expert, Climate Analytics.

Longer and higher overshoot

In the new scenario, global warming reaches 1.5°C around 2030, with warming peaking around 1.7°C and falling to around 1.2°C by 2100. This means the temperature overshoot would last around 40 years – longer and higher than in the IPCC AR6 scenarios, reflecting inaction over the last five years.

This would require electricity to meet almost two-thirds of all energy demand by 2050, with electrification outperforming other options on cost, scalability and energy efficiency. In addition, the high ambition scenario sees electricity, hydrogen, biomass and synthetic fuels “pushing fossil fuels out of the energy system” by 2070 – even 2050 for more advanced economies.

Under this scenario, methane emissions also fall 20% by 2030 and 30% by 2035, compared to 2020 levels. (Countries have made a pledge to reduce methane emissions by 30% by 2030, from a 2020 baseline, but these emissions are still rising despite the fact that abatement is both technologically feasible and cost-effective.)

“Overshoot of 1.5ºC is a woeful political failure and will bring increased damages and risk of tipping points that otherwise could’ve been avoided. But this roadmap shows it is still within our power to bring warming back well below 1.5ºC by 2100. We must do all we can to limit any time we spend above this safety threshold to minimise the risk of irreversible climate damages and the devastation that could be caused by crossing tipping points,” added Bill Hare, CEO of Climate Analytics.