LONDON — Teenage climate activist Greta Thunberg was the odds-on favorite to win this year’s Nobel Peace Prize.

The award would have capped an already extraordinary year, in which Thunberg evolved from a student sitting outside the Swedish parliament, all by herself, to become the leader of a global youth movement, inspiring millions of schoolchildren around the world to join her in calling for greater action on climate change. 

“How dare you? You have stolen my dreams and my childhood with your empty words,” she told world leaders in a blistering speech at the United Nations last month.

But instead of bestowing the prize on the 16-year-old Swede, the Norwegian Nobel Committee gave it to Ethiopian Prime Minister Abiy Ahmed, who was praised for his efforts to “achieve peace and international cooperation.”

Why was Thunberg passed over? How could so many forecasters have been so wrong?

The peace prize selection process is highly secretive — all the committee would reveal was that there were 301 nominations this year. The names of some contenders are made public by their nominators. Thunberg, for instance, was nominated by three Norwegian lawmakers. But the full list will not be released for 50 years. 

It can also be hard to anticipate the winner because the selection reflects the idiosyncrasies of five individuals picked by the Norwegian parliament.

That doesn’t stop people from guessing — or betting — on the winner. On Thursday night, Thunberg was the favorite with bookmakers William Hill (2/5) and Coral (4/7). 

But she had several factors working against her, according to analysts who have followed the award.

Henrik Urdal, head of the Peace Research Institute Oslo, omitted Thunberg from the Nobel Peace Prize shortlist he publishes. 

He explained his decision to The Washington Post, saying there “isn’t scientific consensus that there is a linear relationship between climate change — or resource scarcity, more broadly — and armed conflict.”

Janne Haaland Matlary, a politics professor at the University of Oslo, agreed that Thunberg was a “wild card” nominee. The link between climate change and conflict is still “quite tenuous at this point,” she said. “Everyone sees flooding can cause conflict, migration and so on, but this is in no way well established as a security policy issue yet.”

The prize has gone to environmental champions before. In 2007, the Intergovernmental Panel on Climate Change (IPCC) and former vice president Al Gore won “for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.” In 2004, it was given to Wangari Maathai “for her contribution to sustainable development, democracy and peace.” In 1970, it went to Norman Borlaug, sometimes called the “father of the green revolution.”

But Urdal said such picks would be less likely now, as the prize committee has sought to hew more closely to the original wishes of Alfred Nobel.

In his 1895 will outlining the prize, Nobel wrote that the recipient should be someone who has advanced the “abolition or reduction of standing armies” — which some have interpreted as requiring a direct connection to peace and conflict.

“If you make it too broad, it becomes a bit meaningless,” Urdal said.

Robert Falkner, a climate expert at the London School of Economics, questioned the narrowing of the prize.

“If you want to return to a narrow definition of conflict — as in military conflict or inter-state confrontation, which is in a sense the early 20th century perspective on conflict and war — that’s very antiquated and a rather narrow notion of conflict,” Falkner said.

He added that it’s difficult to prove a direct causal relationship between climate change and conflict, in part because the same crisis can trigger different responses in different countries.

But he said: “Where there are already sources of ecological stress that can spill over into conflict, those will be intensified, multiplied and accelerated. That’s why the Pentagon, [Britain’s Defense Ministry] and NATO are studying this.” The Pentagon has called climate change a “threat multiplier.”

It’s also possible that the timing was not quite right for Thunberg. The committee draws up a short­list “of the most interesting and worthy candidates” soon after the nomination deadline at the end of January. But some of the more impressive moments of Thunberg’s activism — the global climate strikes, her transatlantic voyage on a sailboat, her U.N. speech — came later in the year.

The award undoubtedly would have been a huge public relations boost for the teenage activist, who is now in Denver as part of a tour of North America. But Thunberg has said she does not protest to “get awards and prizes.”

She tweeted Friday to her 2.8 million followers that she would be doing what she does every Friday: demonstrating against climate change.

Of course, at her age, she may have plenty more chances to win the Nobel.