Rocker John Mayer has hit back at critics of Saturday's (07Jul07) Live Earth extravaganza, labelling those that dismiss the climate change awareness-raising event "counter-productive". Mayer, who played at the New Jersey leg of Live Earth, is pleased the global series of gigs is highlighting the problems caused by global warming. Speaking before taking the stage, Mayer said, "I feel this counter claim that's taking place today about whether or not it needs to be done, it's counter-productive. "We want to be healthier and some people are debating whether we need to be and I just don't get it because if you could be healthier, why wouldn't you be? I don't understand what the counter point is."