The Lancet Commission on Health and Climate Change last month concluded that climate change is a risk to public health (N. Watts et al. Lancet http://doi.org/56b; 2015). In the same week, a Dutch court ordered the government of the Netherlands to improve its reduction of greenhouse-gas emissions to protect the population from harm and to keep the country habitable by safeguarding the environment (see Nature http://doi.org/559; 2015). We suggest that this court order is closely studied by other countries. If governments do not act, they should expect lawsuits from families who lost relatives during, say, the heatwaves in Europe in 2003 or in Pakistan and India this year.