A group of countries at the COP26 climate summit have committed to setting an end date for oil and gas exploration and extraction.
The alliance is led by Costa Rica and Denmark, and includes Ireland, France and Greenland.
New Zealand has joined the alliance as an associate member, as has the US state of California.
Aotearoa cannot have core status because of the ongoing provision of on-shore drilling permits, especially in Taranaki.
The plan launched in Scotland overnight is a world-first diplomatic effort to keep fossil fuels in the ground.
International energy and environment agencies say warming cannot be kept below the 1.5C degree threshold if oil and gas production continues to grow.
Oil Change International senior campaigner David Tong said the pledge was a hugely significant development.
Tong told Morning Report it is is one of the biggest announcements from the the COP26 climate meeting in Scotland.
"This is remarkably significant. For 25 years fossil fuels have been the elephant in the room in UN climate talks.
"So now to have 10 countries coming forward committing to ending producing new fossil fuels is a remarkable step forward."
Tong said the move would lead to a reduction in emissions.
Activists say the alliance is a good first step but all countries need to immediately start reducing reducing production.
For the first time ever in UN climate talks, a draft agreement released yesterday mentioned fossil fuels, but there is considerable uncertainty it will make it through the last days of negotiations and into the final document.
The meeting is set to end overnight New Zealand time, but it is likely it could take at least another 24 hours for an agreement to be reached.
New Zealand chided with 'fossil of the day' award
New Zealand's emissions reductions efforts have been been lambasted by an international group of climate activists.
Climate Action Network has given Aotearoa a "fossil of the day" award.
A draft COP26 agreement released yesterday asked countries to strengthen pledges to cut emissions.
The network said James Shaw's comments that it is not compulsory was hypocritical from a country that claims strong green credentials.
It said New Zealand's own pledges are unambitious, last minute and reliant on buying reductions from other countries rather than making domestic cuts.
The network said Aotearoa is blocking efforts in negotiations to set limits on offsets.