"There is a relationship between environmental damage and our increasing problem with pandemics and I wonder whether the Nobel Peace Prize Committee might want to highlight that," he told Reuters.
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If the committee wanted to highlight this trend, he said, "there is obviously the temptation of Greta Thunberg".
The Fridays for Future movement started in 2018 when Thunberg began a school strike in Sweden to push for action on climate. It has since become a global protest.
Thunberg and her father Svante, who sometimes handles media queries for her, did not reply to requests for comment.
Many were skeptical when Greta, as she is often referred to, became the bookmaker's favorite to win last year's Nobel Peace Prize, especially with regards to her age, but her second nomination could strengthen her chances.
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"Greta is renominated, which was the case for Malala. I said Malala was young when she was nominated the first time and I said Greta was young the first time she was nominated," Sveen said. Yousafzai won in 2014.
Other known candidates included the "people of Hong Kong", NATO, Julian Assange, Chelsea Manning and Edward Snowden and jailed Saudi activist Loujain al-Hathloul.