As Extinction Rebellion climate activists began preparing for a fresh year of protests in 2020, their chief concerns ranged from potential new police and legal restrictions on street protests, to how to boost their own numbers, diversity and effectiveness.
Now they have an entirely new worry: a global coronavirus outbreak.
With lockdowns on public gatherings taking hold around the world, the group's best-known tactic - staging mass street protests to focus public attention on climate change threats - is no longer wise or possible for now, activists say.
Instead, Extinction Rebellion (XR) - like the student climate strike movement spearheaded by Swedish teen Greta Thunberg - is looking for new ways to make a mark, from taking its campaigns online to using its networks to battle the virus.
"We are in XR because we are compassionate individuals who have seen the harm coming to everything we love," said Vishal Chauhan, 30, a London-based member of Doctors for XR.
"We act on imminent threats - and that's what coronavirus is right now," said the former emergency care doctor, describing how many members of the movement were redirecting their energies to aiding communities and vulnerable neighbors.
"What this health crisis is doing is making people realize what is important" - and that could help drive action on climate risks in the future, he said.
Climate protest movements surged worldwide in 2019, with youth climate strikes drawing millions out on the streets.
In London, the British government declared a climate emergency and later set a 2050 net-zero emissions target weeks after an unprecedented Extinction Rebellion protest in London.
This month, however, Fridays for Future youth climate protesters have taken their weekly actions digital, using the Twitter hashtag #ClimateStrikeOnline.
"In a crisis, we change our behavior and adapt to the new circumstances for the greater good of society," strike founder Thunberg tweeted to her more than 4 million followers last week.
"We must unite behind experts and science. This of course goes for all crises," the 17-year-old noted.
Activists in countries from India to Sierra Leone and Russia have heeded the call, posting images of themselves holding protest signs on social media, with their posts sometimes coordinated to appear at the same hour.
Those still protesting in person have said they are trying to main the "social distancing" recommended by health officials.
Kenyan youth activist Makenna Muigai said the virus spread had forced cancellation of an Africa-wide strike planned for April 24.
"I'm thinking now everything will be digital," she told the Thomson Reuters Foundation in a telephone interview.
She said the coronavirus pandemic may be cutting emissions globally, as China's industries slow and more people stay at home. But "in terms of getting people's voices heard" on climate issues, it represents a roadblock, she said.
"Right now everyone's focused on the virus. Getting people to also remember and understand that climate change is still a problem might get overpowered," she said.
Medic Chauhan, however, said the strengthening of social and community ties in response to coronavirus, as people work together to confront the threat, could lay the groundwork for more effective future action on climate threats.
"We've so far urged negative disruption. We hope people see our message and it percolates," he said.
But with members now focused on strengthening community ties, "we can start talking to people about the climate crisis as friends", he said.
"It's a much more beautiful way of getting the message across," he added.
For now, the British arm of Extinction Rebellion has said mass public gatherings will not be organized "if it is not safe to do so". That means a planned large-scale London protest in May has been called off.
But "we will make alternative, creative plans for May and June - watch this space", the group promised in a tweet.