Co-exposure to heatwaves and air pollution from landscape fires has been increasing globally over the past two decades, according to a new analysis by Yao Wu and colleagues. Respiratory and cardiovascular health risks from landscape fire-related air pollution, as well as from extreme heat, are well documented. These health risks, and the incidence of the fires themselves, are amplified during stretches of extreme temperatures. Wu et al. found that 55.9% of the global population experienced increasing co-exposure between 2000 and 2019. On average, 916 million people each year experienced at least one co-exposure day, increasing by 287 million people per decade. The global annual average co-exposure was 1.3 days per person, rising from 1 day in 2000-2009 to 1.7 days in 2010-2019. During the study period, the top 5 countries with the highest annual averages of person-days of co-exposure to heatwaves and landscape fire smoke pollution were the Democratic Republic of the Congo, Indonesia, Mexico, Brazil, and the Russian Federation.

A new technique significantly improves weather forecasting beyond two weeks. Researchers developed a machine-learning model that learns to correct errors in existing forecasting models to make their output more accurate over the two-to-six-week time frame, a key window for emergency planning.