Friday, if you did not know it, is World Refugee Day.

And the depressing news is that the number of refugees is at a record high, fuelled in part by climate change which is causing conflicts around the world. Some 40 million people worldwide are already uprooted by violence and persecution, and the figure is set to get worse.

Antonio Guterres, the UN high commissioner for refugees, argues that climate change is uprooting people by provoking conflicts over increasingly scarce resources, such as water.

In an interview with the Guardian newspaper, Guterres said: “Climate change is today one of the main drivers of forced displacement, both directly through impact on environment – not allowing people to live any more in the areas where they were traditionally living – and as a trigger of extreme poverty and conflict.”

Guterres said the number of refugees was likely to continue to increase for the foreseeable future. “More and more the international community will be facing an acceleration of people on the move for all kinds of reasons,” he said.

Guterres said funding from world governments had failed to keep up with the challenge of caring for refugees, describing it as “out of proportion with the dimension of the problem.”

The number of people displaced by climate change will become one of the biggest political issues this century.