Keeping the world on the best pathway to fight global heating will cost a cool $35 trillion of investments by 2030, far above current levels, warned the International Renewable Energy Agency (Irena).

The global renewables body said the energy transition remains well off track to limit global temperature rise to 1.5°C above pre-industrial levels, the key aim of the landmark Paris Agreement sealed at COP21 in 2015.

While worldwide investments in transition technologies hit a record $1.3trn last year, Irena said that needs to quadruple to $5trn-plus to stay on a 1.5°C pathway.

The total global renewables fleet, meanwhile, needs to hit 10,000GW from the current 3,000GW, with Irena stressing the need for green energy expansion to spread far beyond current heartlands such as the US, China and the EU.

Irena released the figures in a preview version of its next World Energy Transitions Outlook, which will be published in full later this year and feed into the ‘Global Stocktake’ of progress on Paris goals set to be unveiled ahead of COP28 in November.

The body is particularly dismayed that some 41% of energy investments scheduled by 2050 are still targeted at the fossil fuel sector.

The UN’s secretary general last week called for developed nations to speed up their net zero ambitions by 10 years to keep the climate fight on course.

Irena director general Francesco La Camera said: “We must rewrite the way international co-operation works. Achieving the energy transition requires stronger international collaboration, including collective efforts to channel more funds to developing countries.

“A fundamental shift in the support to developing nations must put more focus on energy access and climate adaptation. Moving forward, multilateral financial institutions need to direct more funds, at better terms, towards energy transition projects and build the physical infrastructure that is needed to sustain the development of a new energy system.”