"If we don't act now, it'll be too late." That's the warning from Sir David Attenborough ahead of the COP26 climate summit in Glasgow.

The broadcaster says the richest nations have "a moral responsibility" to help the world's poorest.

Our conversation ranged from the latest climate science to the importance of COP26 to the pace of his working life.

The UN climate science panel recently concluded that it is "unequivocal" that human activity is driving up global temperatures.

"And every day that goes by in which we don't do something about it is a day wasted.

But he said the report had not convinced everyone and that they are acting as a brake on efforts to tackle climate change.

His call for an urgent response reflects the latest scientific assessment that to avoid the worst impacts of rising temperatures, global carbon emissions need to be halved no later than 2030.

The argument is that they should be making the deepest cuts in carbon emissions and providing help to those who need it most?

A long-standing promise of $100bn a year for low carbon development and to build stronger defences against more violent weather has yet to be fulfilled - reaching that total will be a key test of whether COP26 succeeds or fails.

"We caused it - our kind of industrialisation is one of the major factors in producing this change in climate.

The COP26 global climate summit in Glasgow in November is seen as crucial if climate change is to be brought under control.

"And the day is going to come when I'm going to get out of bed and say, I don't think I can do that.

Nothing less than speaking, virtually or in-person, to what's set to be the largest ever gathering of global leaders on British soil: COP26, in a few days' time?

The 2050 target controversially omits new short-term goals and cuts to fossil fuel industries.

Attenborough in 'act now' warning over climate

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