Robert Redford is known to support causes he believes in and this time around, the legendary actor is raising awareness as well as money towards the restoration of Colorado River Delta. There's only one problem though — fellow actor Will Ferrell disagrees with him.

Robert Redford (right) and Will Ferrell are known for their environmental activities

Redford wants people to find out how they can help reconnect the Colorado River with the Gulf of California. But instead of bringing the river back to the ocean, Ferrell insists the better way to go is to bring the ocean to the river.

In an upcoming video, the two Hollywood stars go head to head over their differing opinions.