Sir David Attenborough has launched a scathing attack on people in power who do not believe in climate change.
Speaking in front of the UK Parliament's British, Energy and Industrial Strategy Committee on Tuesday, the famous documentary broadcaster said you "can't be radical enough" dealing with current climate problems.
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"I'm sorry there are people who are in power internationally, notably of course the US, but also Australia, which is extraordinary because Australia is having to deal with some of the most extreme manifestations of climate change," he said.
"One hopes the electorate will respond to that."
He warned that failing to tackle the climate crisis would lead to great "social unrest".
"The problem you're opening now is a very serious one. If the world climate change goes on, it is going to be facing huge problems with immigration," he told MPs.
"Large parts of Africa are going to be even less inhabitable than they are now, and there will be major upsets in the balance between our national boundaries.
"These kind of problems are going to grow inexorably and we are going to have to decide what we do about it, that's going to happen."
However, he said he was hopeful for the future due to an upsurge in environmental activism by the young.
"The electorate of tomorrow are already making their voices very clear, that's a source of great comfort," he said.
"It's their futures that are in our hands."