Guardian: As we look back on the past year and look forward to the next, there are clearly huge challenges for our economy. The housing market, consumer spending and economic growth look poised on the edge of a pretty steep drop, and there is a growing chance of a recession. But Gordon Brown – and before him Tony Blair – have stressed that the biggest challenge of our time is the transition to a low-carbon economy. Professor Nick Stern recommended in his report this year that rich …