It seems that every celebrity has a duty of care on their shoulders, and it is expected that they should give back to the community and contribute towards some of the world’s most pressing issues. So here is a list of celebrities who we feel deserve praise for their awareness and contribution to these global issues, and who have gone that bit further than just installing rain water harvesters or ground source heat pumps in their house.

1. Leonardo Dicaprio – The popular star of Inception is one of the leading celebrities to speak out against global warming. Dicaprio also has a website which is devoted to sustainability which is part of the Dicaprio Foundation which was established in 1998. Other courageous acts have seen him create an "eco-town" for the rebuilding of Greensburg, Kansas which was devastated by a tornado. He has frequently won a great deal of deserved praise for a variety of energy saving and environmental groups for his refusal to charter private jets, instead he opts to fly commercially to reduce his personal carbon footprint.

2. Richard Branson – This may seem surprising considering that he is the owner of Virgin Atlantic, whose trains and trans Atlantic flights emit a great deal of CO2 emissions. However, he has not let all the money get to his head, as back in 2006 he pledged to donate all profits from his airline and rail business on investments in biofuel research and projects to tackle emissions over the next 10 years. The estimated profit for Virgin in this timescale is a staggering $3 billion.

3. Harrison Ford – He is a former board member and vice chairman of conservation International having previously impressed with the intellectual capacity of its directors. Since joining Conservation International over 16 years ago, Harrison has donated large amounts of time, money, and land to conservation issues. In 2002 Mr Ford received a Lindbergh Award for his efforts as an environmental river keeper, which identifies and prosecutes polluters of the Hudson River.

4. Jamie Oliver – Celebrity British chef Jamie Oliver has been on a one man mission to rejuvenate and improve the way we eat. Programmes including Jamie at Home, Jamie Saves our Bacon and Jamie’s School Dinners have all been designed to raise awareness of the unsatisfactory eating conditions we accept, and how we can improve these conditions. He has also made sure that his Cornwall restaurant Fifteen is exclusively powered by rooftop wind turbines.

5. Sting – The former front man of The Police has regularly come under fire from critics for both the large carbon footprint of his tours and for seeking publicity for his career. However, he was a founder of Rainforest Foundation in 1989, which is designed to protect rain forests and their indigenous peoples, and over 20 years later he is still contributing to the welfare of rainforests by campaigning to save the Amazon and its inhabitants.

6. Woody Harrelson – Mr. Harrelson has always tried his best to contribute towards a variety of causes which include focuses on biodiesel, getting off the grid, organic & overall good green issues. Some of his efforts include the launch of Reco Jeans, a line that was made with 50% recycled denim. He has also been known to refuse to work on the sets of films unless directors meet his green standards, which include reducing his waste and electricity during production.

7. Kevin Costner – Mr Costner’s environmental efforts have seen him contributing funds towards developing a centrifuge water cleaning system, which he has seen him spend around $20 million trying to develop over the last 15 years. He has also contributed 32 innovative oil-separating centrifuge machines to help the disaster of the BP oil spill which started back in April 2010.