Business Green: Jonathan Porritt, chair of the Sustainable Development Commission and one of the government’s top environmental advisers, has today warned we are entering an era of catastrophic climate shocks in which the prospect of “four Katrinas in one year” is an “entirely credible threat”. Speaking at a conference earlier today hosted by reporting software specialist SAS, Porritt warned that increasingly frequent “climate induced shocks” would become a reality over the next 10 to 20 years and …