By Nate Lippens
Special to MSN

The rising awareness of global warming has sparked a mass interest in environmentalism that exceeds the early conservation movement of the 1970s. Part of this sea change is due to an increased celebrity presence in all matters green. It isn't just talk. Whether it's forsaking a limo in favor of driving a hybrid car to the Oscars or fitting their homes with solar panels, many celebrities are embracing and living green lifestyles.

Actors such as Morgan Freeman, Johnny Depp, Orlando Bloom and Kirsten Dunst drive electric or fuel-efficient cars. Canadian singer Alanis Morisette, who earned the 2003 Environmental Media Association Missions in Music Award for campaigning against oil drilling in Alaska, has a solar home and drives a Prius. She also plans to make her next tour eco-friendly. Neil Young's entire 2004 North American tour was fueled with biodiesel.

Others have taken their personal environments off-road. Sitcom star Julia Louis-Dreyfus and her husband, writer/producer Brad Hall, have been environmentalists for years. Their newly designed home near Santa Barbara, Calif., has been singled out as a showcase of green design and state-of-the-art energy efficiency mechanisms. Cate Blanchett's Sydney home is solar-powered. The Oscar-winning actress, who is a co-director of the Sydney Theatre Company, plans to equip the theatre's building with solar panels and rainwater-collection systems.

Former Agent 007 Pierce Brosnan has been active in environmental causes for years. He frequently posts topics online and discusses with magazines how he and his family have gone green. They consume organic foods, use eco-friendly cleaning products and services, recycle, have an organic garden and compost. Their self-designed house has floor radiant heat and solar vents.

Edward Norton, who grew up with environmentalist parents, has taken eco-consciousness from his solar home to the homes of others by spreading the word among other actors. He launched the BP Solar Neighbours Program in 2003, which matches each celebrity purchase of a solar-energy home system with a solar installation in a low-income family home in Los Angeles. Don Cheadle, Alicia Silverstone, Salma Hayek and Brad Pitt have all participated in the project.

Leonardo DiCaprio has made it a personal and artistic crusade to bring attention to environmental issues. The actor uses his fame to promote green organizations through his Web site, which is divided between causes and his acting career. He is, in fact, a longtime environmentalist, having interviewed President Clinton in 2000 for an ABC Earth Day television special. Currently he serves on the boards of the Natural Resources Defense Council and Global Green USA. His upcoming eco-documentary, "11th Hour," which he produced, co-wrote and narrated, includes the participation of more than 70 experts from various fields on the subject of global warming. DiCaprio lives in a solar house and drives a biodiesel car.

One of the environmental activists with a long track record is Robert Redford. The Oscar-winning icon, now 70, got involved with the grassroots conservation movement when he was 24. At the time, he purchased two acres of land in Utah, which has since grown to 5,000 acres and become the site for the Sundance Institute. In his forties, he became a trustee of the Natural Resources Defense Council and later the founder of the Institute for Resource Management. In April 2007, the Sundance Channel launched a weekly three-hour slot called "The Green" dedicated to the environment. Redford's "The Heat Is On" campaign is aimed at making global warming a talking point for the 2008 U.S. presidential election. However, Redford doesn't only make a difference through causes; he also uses solar power for his home and drives a biodiesel vehicle.

Daryl Hannah has become a noted eco-celebrity. She was arrested in June 2006 for staging a 23-day tree sit-in during a bid to preserve an urban community garden in Los Angeles. The actress not only tours the country discussing green issues but also attempts to establish a national biodiesel standard. Determined to stave off fears that producing some green fuels may do more harm than good for the environment, Hannah and Willie Nelson are spearheading a group called The Sustainable Biofuels Alliance. They are pushing to establish norms for biodiesel production by September 2007, which will place checks on the supply chain and accredit firms producing green fuels. Hannah lives one of the most environmentally radical lifestyles of any green celebrity. She lives completely off-grid in the Rocky Mountains on an organic farm.