His stepfather, Carsten Jensen, said on Facebook that Coleman “collapsed without prior health problems” during a trip. Coleman was born in London and appeared in several movies as a child, including “The Fourth Kind” and “It’s Alive.” He was best known for playing Eric Brown, aged 11, in the 2005 British comedy movie “Nanny McPhee,” alongside Emma Thompson, Colin Firth and Angela Lansbury. His former castmate, Eliza Bennett, said she was “heartbroken” at the news. “After we worked on Nanny McPhee, he dedicated his life to protecting wildlife and fighting climate change,” she wrote. He became an active member of...