The meeting - attended by representatives from China, Cuba, Nicaragua and Venezuela among others - was presided over by the Bolivian President Luis Alberto Arce Catacora.
Modi on Tuesday called for One Sun, One World, One Grid' to improve the viability of solar power
Among the new signatories was Brazil - one of the world's five biggest emitters of methane.
That puts it well behind its peers who are gearing up to buy green assets, crack down on fossil-fuel lending, and push companies toward lower-carbon choices.
Prime Minister Narendra Modi on Monday said that he feels it's his duty to raise the voice of developing countries while addressing the COP26 Global Leaders' Summit here in Glasgow.
Aarti Khosla, Director, Climate Trends, said, By announcing a commitment for achieving net zero targets by 2070, India has responded positively to the global call and it was the best climate action.
Indian Prime Minister Narendra Modi delighted delegates at the COP26 climate summit with his announcement that the third-biggest emitter would reach net-zero by 2070.
Foreign Secretary Harsh Vardhan Shringla said that PM Modi's announcement on net-zero emissions is "very significant for India and the rest of the world."
Modi also upped the renewable energy target of the country to 500 Gw by 2030
Speed & Scale is an actionable manifesto for humanity to save the planet from us
In an interview with Jyoti Mukul & Shreya Jai, International Solar Alliance (ISA) Director-General (D-G) Ajay Mathur says India and the UK have combined their green grid initiatives
The key to achieving reduction of emissions is development of alternate fuels by the oil industry
The leaders' first face-to-face gathering since the start of the COVID pandemic - focused mainly on health and the economy, while climate and the environment is front and centre of Sunday's agenda.
Expecting both rich and poor countries zero out their emissions at the same time would be unjust
Vulnerable countries are stepping up amidst a slow response from some of the biggest emitters, a UN report said
Says India's Gati Shakti plan could spur clean energy investment; no other country has any new spending plans
Large companies must convince the SBTi that they have a credible plan to halve their emissions before 2030 and eliminate 90-95 per cent of emissions before 2050 compared with a base year after 2015
COP26 climate talks could be the last chance to curb warming
Many of the net zero commitments are disappointing
If COP26 fails, it will be because of misplaced targets from the West and China, and a lack of ambition and imagination from India