Prof Jim Hansen: 'We’re handing future generations a climate system which is potentially out of their control'. Melanie Patterson / AP

By Severin Carrell, www.guardian.co.uk
6 April 2012 Averting the worst consequences of human-induced climate change is a “great moral issue” on a par with slavery, according to the leading Nasa climate scientist Prof Jim Hansen. He argues that storing up expensive and destructive consequences for society in future is an “injustice of one generation to others”. Hansen, who will next Tuesday be awarded the prestigious Edinburgh Medal for his contribution to science, will also in his acceptance speech call for a worldwide tax on all carbon emissions. In his lecture, Hansen will argue that the challenge facing future generations from climate change is so urgent that a flat-rate global tax is needed to force immediate cuts in fossil fuel use. Ahead of receiving the award – which has previously been given to Sir David Attenborough, the ecologist James Lovelock, and the economist Amartya Sen – Hansen told the Guardian that the latest climate models had shown the planet was on the brink of an emergency. He said humanity faces repeated natural disasters from extreme weather events which would affect large areas of the planet. “The situation we’re creating for young people and future generations is that we’re handing them a climate system which is potentially out of their control,” he said. “We’re in an emergency: you can see what’s on the horizon over the next few decades with the effects it will have on ecosystems, sea level and species extinction.” Now 70, Hansen is regarded as one of the most influential figures in climate science; the creator of one of the first global climate models, his pioneering role in warning about global warming is frequently cited by climate campaigners such as former US vice president Al Gore and in earlier science prizes, including the $1m Dan David prize. He has been arrested more than once for his role in protests against coal energy. Hansen will argue in his lecture that current generations have an over-riding moral duty to their children and grandchildren to take immediate action. Describing this as an issue of inter-generational justice on a par with ending slavery, Hansen said: “Our parents didn’t know that they were causing a problem for future generations but we can only pretend we don’t know because the science is now crystal clear. “We understand the carbon cycle: the CO2 we put in the air will stay in surface reservoirs and won’t go back into the solid earth for millennia. What the Earth’s history tells us is that there’s a limit on how much we can put in the air without guaranteeing disastrous consequences for future generations. We cannot pretend that we did not know.” […]

Nasa scientist: climate change is a moral issue on a par with slavery