This Guardian long read by Ben Rawlence documents how rapid Arctic warming is driving the treeline north, transforming tundra into forest, damaging reindeer grazing and threatening Sami culture and livelihoods; it is included in PART 1: The Purposeful Investor (Call to Action: Our World & Our Future) because it vividly illustrates the real human, ecological and economic consequences of climate change that underpin the book’s argument for mobilising purposeful capital and the “5 Ts” (treasure, time, talent, ties, testimony) toward adaptation, sustainable development and renewable energy opportunities while supporting vulnerable indigenous communities.