Extinction Rebellion has shut down London at four sites – Parliament Square, Oxford Circus, Waterloo Bridge and Marble Arch – for the past four days and has said that protests will continue for the next couple of weeks.
But the protesters have attracted criticisms in the press and from some politicians for their tactics, which have included glueing themselves to a commuter train in Canary Wharf, east London.
The Shell headquarters in London was also vandalised by a small number of protesters earlier this week, and more than 400 people have been arrested by police.
In a statement, Friends of the Earth said that it supported the protests and the tactics had brought "urgency" to the debate.
Aaron Kiely, campaigner at FoE, said: "Extinction Rebellion has brought a much-needed urgency to the climate debate and we want the same things: to stop catastrophic climate change.
"Peaceful protest is an important part of democracy and a various tactics are needed."
Kiely said that FoE was more focused on "solutions", such as a recently unveiled climate action plan, but the protesters were part of a "broad coalition" calling for urgent and substantive action on climate change.
"We’re already seeing the devastating destruction and horrendous loss of life caused by wildfires, floods and extreme weather around the world because of inaction," Kiely said.
"This is about government’s failure to act at the scale needed, leaving people feeling that their only option is to put their bodies on the line to protect the future of the planet.
"Throughout history, peaceful protest by ordinary people has been a catalyst for change. Friends of the Earth recognises that we need a broad coalition, all clamouring loudly for action, to deal with this crisis before it’s too late."
A spokesman for Greenpeace told Third Sector that the organisation was "broadly supportive" of the protests and the publicity it was generating for the issue of climate change.
Greenpeace has recently launched a petition calling for the government to declare a "climate emergency" and take action to prevent environmental ruin.
"We need the government to declare a climate emergency and take immediate radical action on climate change – because that’s what’s required for our survival," the petition says.
The protests in London are part of a series of demonstrations in 80 cities in 33 countries, including Edinburgh and The Hague, where the international criminal court was occupied by activists.