Our high-carbon lifestyles are unhealthy—and not just for our planet. If we would cut red meat and dairy consumption, a UCL Institute for Human health and performance director says, we would make big savings in methane, a potent greenhouse gas. It would also boost our health. Similarly, choosing to leave the car and walk or bike more, will not just save carbon emissions, it will also improve our respiratory health and reduce cardiovascular disease. The European Commission has estimated annual savings of well over 30 billion euros in health care costs with quite modest reductions in greenhouse gases.