Oliver Conway

In the central province of Anhui, Mr and Mrs Guo, both in their 70s, are chopping wood to keep warm.

A low, thick smog forms around them from the nearby tall smoke towers of a large coal plant.

They point me towards their home.

It's submerged in water.

I didn't manage to save anything.

China's insatiable need for energy has been a source of irreversible harm here.

In 2007, a coal company built one of Asia's largest underground mines.

The land gave way, subsided.

Tens of thousands of people had to be relocated.

Some refused, including Mr and Mrs Guo, who now live in a makeshift home.

No one will employ us.

If we stay, at least we can grow crops.

The local government has turned this environmental crisis into an opportunity.

It built one of the world's largest floating solar installations on the lake, which it says generates enough power for 21,000 homes.

And yet, more than half of China's energy needs still come from coal.

This country is running two races at once.

It's trying to keep the lights on and its factories working alongside its shift towards renewables.

How it manages this race in the next decade has the potential to affect us all.

Laura Becker reporting from Mongolia.

Just over a year ago, British couple Craig and Lindsay Foreman were driving through Iran on an around-the-world motorbike trip when they were arrested.