Hello and welcome to Business Daily from the BBC with me, Manuela Saragossa.

Coming up, so you're going on holiday after months of lockdown

and you're going to pay extra to offset your flight's carbon emissions

by planting a few trees or saving a bit of rainforest.

But does that actually make environmental sense?

When you're buying these offsets, when you're clicking the button in this website or your airplane company,

you don't really know from where those offsets are coming from.

Well, how about flights that run on old cooking fat instead?

They actually take the trash out of your trash can and they convert it into jet fuel. So today

you can use waste oils from cooking processes. Folks are looking at capturing gas and making

sustainable aviation fuel. The aviation sectors attempts to go green coming up here in Business

Daily from the BBC.

So over the 30 years that I've been flying, it would never have dawned to me that there was anything bad with what I was doing, you know, but something changed radically in 2019.

Meet Mancan McGahn. He's a well-known Irish travel writer who's given up on travelling by plane.

A lot of things came about at the same time. I suppose first, these very dire warnings came

from international environmental organisations, saying like the threat of global warming and climate

change was becoming imminent and was more ominous than we ever imagine.

Nature is angry. The year's 2015 to 2019, the five hottest year on the books ever.

We have the smallest amount of sea ice in the Arctic and all the mountain glaciers are melting and sea level is rising.

Climate change is one of the most important challenge for us, as European Union.

And at the same time, you know, Exor, the Extinction Revolution protests,

were happening in Dublin, were happening in London, all over the world.

...