It sells T-shirts, mugs and socks featuring the 93-year-old natural historian's likeness.
The science behind global warming will be examined by a Cumbrian climate change expert on television tonight.
Professor Mike Berners-Lee is appearing on Sir David Attenborough's latest environmental documentary for the BBC.
In a wide-ranging interview with Mike Zeller at Breakfast, the academic from Kendal praised the children and young people who've walked out of school to take part in Youth Strikes for Climate:
It's them doing their own thinking about the future for the world they are going to be in and their children are going to be in, so I'm totally supportive."
- Climate Change - The Facts is on BBC One at 21:00.
Sir David Attenborough is back on BBC One presenting a documentary called Climate Change - The Facts