What Counts as Scientific Knowledge?

In September 2019, when 16-year-old climate activist Greta Thunberg addressed the US Congress on climate change, she brought the Intergovernmental Panel on Climate Change (IPCC) report on global warming as her testimony. ‘I don’t want you to listen to me. I want you to listen to the scientists’, she said, referring to the broad scientific consensus behind the report. If the vast majority of scientists agree about the causes and effects of climate change, then why would anyone rationally distrust them?