A row over the definition of the term “gender” threatens to bog down pivotal talks at the Cop30 climate summit. Before the UN talks in Brazil, hardline conservative states have pushed to define gender as “biological sex” over their concerns trans and non-binary people could be included in a major plan to ensure climate action addresses gender inequality and empowers women. “These are unprecedented times to negotiate on gender equality and women’s empowerment,” said Lorena Aguilar, the executive director of the US-based Kaschak Institute for Social Justice for Women and Girls, and Costa Rica’s former vice minister for foreign affairs.