What we need is both stimulus and long-term investments that accomplish two objectives simultaneously with one global economic policy response – a policy that addresses our urgent and immediate economic and social needs and that launches a new green global economy. In short, we need to make “growing green” our mantra

First, a synchronised global recession requires a synchronised global response. We need stimulus and intense co-ordination of economic policy among all main economies. We must avoid the beggar-thy-neighbour policies that contributed to the Great Depression. Co-ordination is also vital for reducing financial volatility, runs on currencies and rampant inflation as well as for instilling confidence on the part of consumers and investors. In Washington last November, leaders of the Group of 20 nations expressed their determination “to enhance co-operation and work together to restore global growth and achieve needed reforms in the world's financial systems”. This needs to happen urgently.

Stimulus is intended to jump-start the economy, but if properly conceived and executed it can also launch us on a new, low-carbon path to green growth. Some $2,250bn (€1,750bn, ￡1,569bn) of stimulus has already been announced by 34 nations. This stimulus, along with new initiatives by other countries, must help catapult the world economy into the 21st century, not perpetuate the dying industries and bad habits of yesteryear. Indeed, continuing to pour trillions of dollars into carbon-based infrastructure and fossil-fuel subsidies would be like investing in subprime real estate all over again.