To mark the start of the UN Climate Change Conference, or COP26, taking place in Glasgow in the UK, we’re looking back at the history of our awareness of climate change with some of the scientists and activists who have been trying to solve this global crisis in recent decades. We hear from environmental activist Severn Cullis-Suzuki, who was just 12 years old when she implored world leaders to take action, at the 1992 UN Earth Summit in Rio De Janeiro. Plus, how a pioneering American scientist provided compelling evidence of man-made global warming back in the 1950s, and measuring melting glaciers at the top of Mount Kilimanjaro in Tanzania.

Photo: Severn Cullis-Suzuki (2nd left) and her friends at the Earth Summit in Rio in 1992. Courtesy of Severn Cullis-Suzuki.