Abdullahi Majeed was a young delegate for the Maldives when low-lying island states warned for the first time in 1989 that climate change and rising seas could "threaten the very survival" of some nations.
Now a 60-year-old veteran, Majeed is still repeating that message, one of a handful of delegates to this month's Paris climate summit who have been attending tortuous UN negotiations to combat global warming from the start.
"It's frustrating," he said. "The sense of urgency is simply not there."
In countless conference halls from Bangkok to Buenos Aires, Majeed has seen more setbacks than breakthroughs, not least the failed Copenhagen conference in 2009.
He is now pinning cautious hopes on the Paris summit, from November 30-December 11, when almost 200 nations will once more seek an accord to curb manmade greenhouse gas emissions, blamed by almost all leading climate scientists for rising global temperatures and sea levels.
"There is more hope," he said. "We can't have another Copenhagen."
In November 1989, Majeed was head of his country's meteorological service when 14 island nations met in the capital of the Indian Ocean archipelago to sign the Male Declaration about the risks of climate change.
It went almost unnoticed outside the signatories, which included Grenada, Fiji and Malta. At the time, few scientists blamed mankind for global warming, and the fall of the Berlin Wall a week earlier was dominating the world's headlines.
"We knew it wouldn't be plain sailing but we thought ‘We have to begin somewhere’," Majeed said.
Now, the risks are far more widely known. Sea levels have risen by about 20 cm (8 inches) since 1900 and the UN panel of climate scientists says they could swell again by between 26 and 82 cm by the late 21st century, driven by a thaw of ice from Greenland to Antarctica.
That would be a creeping threat to coasts from Bangladesh to Florida, to coastal cities from London to Shanghai and to many low-lying coral atolls. The Maldives, with a population of 345,000, is among the most vulnerable since its highest natural point is just 2.4 meters (8 feet) above sea level.
Robert Van Lierop of Vanuatu, the first chair of the Alliance of Small Island States (AOSIS) from 1991-94, said Majeed had helped to set the tone for island negotiators by blending concern with humility.
"Through the ups and downs of the negotiations, he has been a steady rock," Van Lierup said.
Majeed, now Minister of State for Environment and Energy, said he had first become interested in the weather as a child when his father had been unable to answer the question "How do you measure rainfall?".
Delegates often jokingly liken the negotiations to herding cats. Just like AOSIS, now grown to 44 members, the United States, China, African nations, OPEC oil producers or left-wing Latin American states all have often-competing national interests.
OPEC nations, for instance, immediately realized that any shift to wind and solar power was a threat to oil exports. At climate talks in the early 1990s, "half of the OPEC delegates were lawyers", Majeed said.
It was not until 1992 that a UN climate convention in Rio de Janeiro finally set a goal of limiting greenhouse emissions to 1990 levels by 2000, albeit only for developed economies. But the goal was non-binding, and was not met.
After a grind of unproductive annual UN meetings, the next accord was the UN's 1997 Kyoto Protocol, which initially obliged about 40 rich nations to cut greenhouse gas emissions by about 5 percent below 1990 levels in the period 2008-12.
Those cuts have been met overall, but Kyoto had fatal flaws, and the number of participants in an extended period to 2020 has shrunk to a small core around the European Union.
US President George W. Bush concluded that Kyoto was giving big emerging economies such as China and India a free ride, and would cost US jobs. Having signed the deal, Washington never ratified it.
"It was a very minor step in the right direction," Majeed said, remembering that his delegation had to leave before the agreement was reached, in overtime, to avoid missing their expensive flight home.
One of the lowest points was a two-week meeting in Buenos Aires in 2004, which ended with an agreement merely to hold a seminar about climate change the following year. To some, given the US opposition to Kyoto, even that was a victory.
"At the time, I was very happy to get this workshop," said Yvo de Boer, the UN climate chief from 2006-10 who was a senior member of the Dutch delegation in Buenos Aires.
He says the core problem is that climate change ultimately means transforming the world economy.
Crops will have to be replaced or planted elsewhere, for instance, industry will have to find new ways of working without fossil fuels, and low-lying countries may one day have to move whole cities.
"If it was just about cutting emissions, it would be much easier," said de Boer, who now heads the Global Green Growth Institute in South Korea.
Majeed said the pace picked up in Bali in 2007, when nations agreed to work out a global accord to succeed Kyoto within two years. Washington dropped its opposition at a stormy final session during which US delegates were booed.
But the 2009 Copenhagen summit failed, with only a partial accord for emissions cuts until 2020 and a promise to mobilize US$100 billion a year in climate finance for developing nations by 2020. By last year, about $62 billion had been amassed.
Majeed says Copenhagen was the worst meeting: "People started with such optimism, and it ended with such doom."
Prospects for a global accord are now brighter, partly because the United States and China are working together. But ambitions are also lower: a Paris accord will compile voluntary national pledges for action beyond 2020, forsaking the binding model of Kyoto.
In Male, Majeed lives in a house that is about 2 meters (7 feet) above sea level and 50 meters from the waterfront. He grumbles that there are few beaches, because of the sea defenses that occupy much of the capital's coast.
After the Paris talks, set to take place under heightened security after the attacks that killed 129 people last week, he reckons he may stay with climate negotiations for another five years.
"Nobody likes traveling to so many places," he said. "We all have families too." Majeed has four daughters.
Asked why he has stayed on so long when many others have given up, he shrugs: "I've got climate in my veins."