Cannabis has a shocking environmental cost – here’s how to fix it

When California legalised the recreational use of cannabis in 2016, Houston Wilson saw an opportunity to study the plant’s environmental impact. To say his research has been challenging would be an understatement. He was refused official permission to visit farms in 2018 because some of his funding comes from US federal sources – and cannabis is still illegal at the federal level. Even meeting marijuana growers in neutral venues proved difficult, because some farmers were still unwilling to talk after operating outside …