The Paris climate summit is a real test of humanity

The best and worst in our natures are rising to meet a critical point in our history, but there is no cause for despair

This morning I visited the place de la Ri(C)publique, in many ways the beating heart of Paris. It's where people here chose to place their memorial to the victims of the attacks two weeks ago, and there is still a huge crowd, gathered round the central monument in intense, almost ritual silence, taking in the thousands of pictures, candles, flowers and messages left by wellwishers.

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