Black summer

BLUE MOUNTAINS, AUSTRALIA, 11 JANUARY

Much of the Australian bush started the year ablaze, as wildfires that began towards the end of 2019 continued to rage. This shot shows a van crawling through a mix of fog and thick smoke that engulfed the Ruined Castle area of the Blue Mountains, about 75km (45 miles) outside of Sydney.

The fires raged into March, burning an estimated 200,000km2 of land, destroying nearly 6,000 buildings and killing more than 30 people. The environmental cost is more difficult to estimate, but countless animals lost their lives in the flames, with some species believed to have been driven to extinction.

Bush fires can be caused by lightning strikes, or sparks accidentally created by humans. But the hotter, drier climate experienced in Australia in recent years is contributing to the fires becoming more frequent and intense, scientists say.