Many politicians including the UK prime minister Rishi Sunak trace their environmental conscience to their children. Wanjira Mathai can trace hers to her mother — Wangari Maathai, the late Kenyan activist who won the Nobel peace prize for her work linking tree-planting, women’s empowerment and the fight for democracy.

“My strongest memories were just how much we had to plant trees. Every celebration we had, we had to plant something. We lived in an estate which had relatively small compounds, but our compound was known because there were trees everywhere. People would say: if you want to know where they live, just follow the trees, you’ll get there. My mother was very conscious of the fact that planting a tree was a celebration.”

The family planted trees to mark birthdays, holidays and good fortune. “If my grandmother was unwell and went to the hospital, when she came back, we would plant a tree. On independence day, we would plant a tree. We were always planting.” As they ran out of space for trees, they planted flowering shrubs instead. Her mother and the fellow members of her Green Belt Movement took pleasure in their activism. “I always remember spending time around very happy people,” says Mathai.