BBC News:- About 100,000 people marched in Glasgow to demand more action on the climate crisis, organisers have said. The protest was the biggest so far during the COP26 summit and took place alongside hundreds of similar events around the world. Greta Thunberg joined the march but did not speak, leaving activists such as Vanessa Nakate to address a rally. Police arrested 21 scientists who chained themselves together and blocked a road bridge over the River Clyde. Officers also contained a group of socialist activists after pyrotechnics were set off during the march - one person was then arrested. However