“Joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance.” This does not seem to be true on earth, however, at least if the penitent is George W. Bush and his repentance is over the administration’s past recalcitrance on climate change.

Yet his shift is important. The chances that the summit of the group of eight leading countries in Germany this week will prove a significant event have increased. Nobody expects much from this increasingly outmoded talking shop of the complacent rich. But the leaders have a chance to surprise the legions of doubters this time.