Scientists say calamities on same scale as disaster that has killed 169 will become more common if emissions not cut

The unusually intense, prolonged and extensive flooding that has devastated southern Brazil was made at least twice as likely by human burning of fossil fuels and trees, a study has shown.

The record disaster has led to 169 deaths, ruined homes and wrecked harvests, and was worsened by deforestation, investment cuts and human incompetence.

The team of international scientists behind the study predicted that calamities on this scale – the worst to hit the region – would become more common in the future if there was not a sharp reduction in the greenhouse gas emissions heating the planet.