In the last few years global awareness of climate change has grown very rapidly--through the school strikes led by Greta Thunberg, groups like Extinction Rebellion, the IPCC's recent high impact reports, TV documentaries, and declarations from governments around the world that we are in a climate emergency. This awareness is continuing to grow, as the science shows us that our planet and our species are facing a massive crisis, which we ourselves have caused. Climate change is one of the few scientific theories that make us examine the whole basis of modern society. It is a challenge that has politicians arguing, sets nations against each other, queries individual lifestyle choices, and ultimately asks questions about humanity's relationship with the rest of the planet. This Very Short Introduction draws on the very latest science from the 2021 IPCC Report, examining the evidence that climate change is already happening, and discussing its potential catastrophic impacts in the future. Mark Maslin also explores the geopolitics of climate change and the win-win solutions we can employ to avoid the very worst effects of climate change. Throughout, he demonstrates how we must develop new modes of thinking for the twenty-first century at individual, corporate, and government levels to collectively tackle the challenge of climate change.