A strike by a medium-size asteroid could change Earth’s climate dramatically for a few years, making life difficult for people around the world, a new study suggests. Such an impact on land (as opposed to at sea) could cause average global temperatures to plunge to ice age levels and lead to steep drops in precipitation and plant productivity, among other effects, researchers said. “These would not be pleasant times,” Charles Bardeen, of the National Center for Atmospheric Research in Boulder, Colorado, said in December during a presentation at the annual fall meeting of the American Geophysical Union (AGU) in San Francisco.

Bardeen and his colleagues modeled what would happen to Earth’s climate if a 0.6-mile-wide (1 kilometer) space rock plowed into one of the planet’s landmasses. Such an impact would probably gouge out a crater about 9 miles (15 km) wide, throw huge amounts of dust into the atmosphere and trigger large-scale fires that lofted lots of soot into the air, provided the strike didn’t occur in a desert area with little vegetation, Bardeen said. FULL REPORT