The summit meeting of the Group of Eight industrialised nations that opened in Italy on Wednesday looks increasingly like an event in search of a purpose. The more broadly based G20, including China and India among others, is the place where deals on the global economy are being done. So what is the point of the G8?

The answer should be: to galvanise the debate on climate change. A consensus is needed between the rich and poor for a new deal to slow down global warming. It is supposed to be finalised by the United Nations at Copenhagen in December. But to have any hope of progress there, the leaders gathered in L’Aquila this week must give a clear sense of direction.