This is the Guardian.

Today, there will meant to be a key tool in the way corporations fight global heating.

So why are so many carbon credits worthless?

A rainforest the size of England disappears each year.

So the value of standing forests can only rise.

You probably heard advertisements like these.

And high quality nature-based carbon credits could also play a valuable role in the carbon

exploring ways to help further offset growth in aircraft emissions,

such as investing in the repair of damaged peatland to remove carbon from the atmosphere.

We were the first airline to participate in emissions trading and set ambitious climate targets.

Now as part of our journey with BA Better World.

Talking up the power of emissions trading or carbon credits to help solve the climate crisis.

It's a complicated industry but the premise is pretty simple.

Pay for projects somewhere in the world that reduce the amount of carbon in the atmosphere.

And in exchange you can keep polluting yourself.

Carbon credits are becoming big business worth about $2 billion a year and expected to grow to 10 times that size by the end of the decade.

They sell a kind of dream that in the face of an environmental crisis that demands

big polluters cut their emissions fast.

They end all of us might be able to buy our way out of the problem.

But a major new investigation.

One that stretches from the UK to the Peruvian Amazon and the boardrooms of some of the largest

companies in the world has reached a damning conclusion.

...