We all know Leonardo DiCaprio's got a well-developed social conscience, so the folks at Christian Aid must be overjoyed that he's pledged his support for their Cut The Carbon March.
The march, which sees a core of 18 marchers walking through 70 towns and cities and is already underway, is expected to see 50,000 people join before it's finished - and Leo certainly thinks it's a good idea.
DiCaprio said: "I’m very proud to support Christian Aid and Stop Climate Chaos in this effort. These rallies are a critical step in bringing much-needed attention to the damage global warming is doing now to the world’s poorest countries.
"As I learnt while making the documentary The 11th Hour, it’s going to take all of us to work to curb carbon emissions, so I urge people to register their support and pressure governments to change by going to the Cut the Carbon march."
Paul Brannen, head of campaigns at Christian Aid, said: "Climate change is the most serious threat to humanity. Poor people in the least developed countries are already dying as a result of floods, droughts and conflict over already scarce resources, such as water, that are becoming scarcer as the planet heats up.
"They need our help to tackle climate change by reducing emissions, through individual action and by putting pressure on the UK government to pursue climate friendly national and international policies."
If you want to get involved but don’t want to don your walking boots, join in the virtual march here