Filipino delegate whose town was destroyed by typhoon remains in limelight after pledging not to eat until talks yield progress

It might have been Robert Lewandowski, or any other high-profile footballer. But the shy, bespectacled young man blinking in the spotlights and surrounded by 100 TV cameras, journalists and gawpers in the bowels of Poland's national football stadium was a Filipino civil servant more used to negotiating the finer points of verifiable emission reductions, or loss and damage than meeting the world's media.

Yeb Sano, leader of the 50-strong Philippines delegation at the UN climate talks, shot to carbon stardom last week when he made an emotional speech in front of 190 countries.

Linking manmade climate change to typhoon Haiyan, which had just obliterated his hometown, he broke down in tears and declared he would fast until the UN talks produced results. Having asked people to sign a petition demanding progress, he disappeared into the talks. About 200 people subsequently joined him on his fast.

On Tuesday, after seven days without food, he surfaced from the negotiations for a photocall to find that – boosted by calls to action from organisations including 350.org, MoveOn, Friends of the Earth, Credo Action and 18 Million Rising – the petition he authored on Avaaz now bears more than 600,000 signatures.

Sano's words, a mix of the personal and political, were difficult to catch over cameras: "It's a difficult time for the planet … we are deeply moved … I am standing here with hundreds if not millions of people … we are heartened … thank you … I am feeling well … I never used the word hunger … I don't think we should wait for the politicians … we need [to do] something urgently."

Members of his delegation stood on the sidelines, protectively. "He is always in high spirits, and energetic," said one. "We are 100% behind him. He has helped put the issue on to the world stage. The fact that so many young people support him is good."

Yano does not expect to eat at least until the talks finish in the early hours of Saturday. "He will take a few days to recover," said his chief of staff, Desiree Dee.

Whether that will be from the ordeal of the climate talks or his newfound celebrity status, she did not say.