Al Gore's campaign to warn of the dangers of climate changes steps up another gear with this weekend's Live Earth concerts.Yet while global warming is widely thought to be the biggest crisis facing mankind, a new survey suggests more than half of us believe global warming threat has been over-hyped.The poll of more than two thousand people discovered 56 percent believe scientists are still questioning climate change.It also found that terrorism, graffiti and crime were all greater concerns.As such the former US Vice President turned environmental campaigner , who arrived in Britain for this weekend's Live Earth concerts, is facing an uphill battle to win hearts and minds in his environmental battle.Yet despite the doubts about the events' message, thousands of music fans will attend concerts across the world to see a stellar line-up of artists.Artists set to perform include Madonna, The Police, Lenny Kravitz and Bon Jovi to name but a few.© Independent Television News Limited 2007. All rights reserved.