In 2019, as the 2019 Amazon rainforest wildfires began intensifying in Brazil, Bolivia, Paraguay, and Peru, as a result of slash-and-burn deforestation and the effects of climate change, Harris called out Brazilian President Jair Bolsonaro for his failure to act. She later joined her Senate colleagues in urging U.S. Trade Representative Robert Lighthizer to postpone trade negotiations with Brazil until he took steps to combat the illegal deforestation.