The G20 emphasised that investments should align with the goals of the Paris Agreement.
The G20, under India's presidency, said on Saturday that developing countries will need $5.9 trillion in the pre-2030 period to implement their national climate plans effectively, with the aim of holding global warming to well below 2 degrees Celsius, preferably 1.5 degrees Celsius.
To achieve net-zero emissions by 2050, developing countries will require approximately $4 trillion annually for clean energy technologies by 2030, the bloc said.
The G20 also urged developed countries to fulfil their commitment to double their collective adaptation finance provision by 2025, compared to 2019 levels.
Comprising nations responsible for 85 per cent of the world's GDP and 80 per cent of emissions, the G20 emphasised the need for increased global investments to align with the goals of the Paris Agreement.
They called for a substantial scaling up of investment and climate finance, transitioning from billions to trillions of dollars from all sources.
The New Delhi Leaders' Declaration, adopted on Saturday, emphasised the necessity of aligning financial flows with climate objectives while expanding finance, capacity-building, and technology transfer with a focus on the priorities and needs of developing countries.
"To achieve this, we note the need for $5.8–5.9 trillion in the pre-2030 period for developing countries, particularly for their National Determined Contributions (NDCs), as well as the requirement of $4 trillion per year for clean energy technologies by 2030 to reach net-zero emissions by 2050," the Declaration read.
The developed countries in the bloc reaffirmed their commitment, dating back to 2009, to jointly mobilise $100 billion in climate finance annually by 2020, continuing through 2025. Developed-country contributors anticipate achieving this goal for the first time in 2023.
The G20 also called for ambitious, transparent, and trackable New Collective Quantified Goals (NCQG) of climate finance in 2024, from a floor of $100 billion a year. They said this should consider the needs and priorities of developing countries in alignment with the United Nations Framework Convention on Climate Change and Paris Agreement objectives.