Climate scientists applaud Hansen for leading the predictions of climate change's effects. But some say these predictions were exaggerated. For example, he has said in recent years that vast carbon dioxide emissions might ultimately cause a runaway greenhouse effect like on Venus that would boil the oceans and make Earth uninhabitable, the Times reported. Other scientists say this hasn't happened in the past and that Hansen overstated the risk.
Hansen was embroiled in a political fight in 2005, when a young political appointee in George W. Bush's administration tried to muzzle Hansen in the press. But Hansen revealed this to the public in an interview reported by the Times, and the administration lifted its restrictions.
Despite his environmentalist stance, Hansen has also criticized the environmentalist movement. He strongly opposed a failed climate bill in 2009, because he said it would have given the federal government billions of dollars without truly limiting emissions.
Hansen, who is registered as an independent, believes carbon dioxide emissions should be taxed, but that the money should be returned to the public as a rebate, instead of going to the goverment.
Hansen told the Times he senses a mass movement on climate change is beginning, led by young people, which he plans to support.
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