Koch, who is living on the International Space Station, posted several photos of the smoke from Australia’s fires, as seen from her vantage point 250 miles (400 kilometers) above Earth.
Approximately 70% of Australia’s 3 million square miles of land is covered by a layer of gray and brown smoke. According to NASA, the smoke had already traveled halfway around the planet by January 8, “turning the skies hazy and causing colorful sunrises and sunsets” in South America.
As of last week, the wildfires — some of the worst in Australia’s history — had burned approximately 25 million acres, claimed the lives of 27 people, and destroyed over 2,000 homes. A billion animals are feared dead.
Australia’s smoke from space
Satellites have tracked the growth of Australia’s bushfires for weeks. Cameras also pinpointed the blazes’ hotspots in infrared light, which is invisible to the human eye. That data can reveal the centers of blazes, so the information is sent to land managers and firefighters working to contain the outbreaks.
Particulate matter from smoke can irritate people’s eyes and respiratory systems and exacerbate chronic heart and lung diseases. In the US, an estimated 20,000 people die prematurely each year due to chronic exposure to smoke, according to the Associated Press.
The fires in Australia began in September but picked up significantly in December, which was Australia’s driest December on record. Last year was the country’s hottest on record, according to Australia’s Bureau of Meteorology.
Many affected areas have gotten rain and slightly lower temperatures over the last week, which has provided some relief, but the majority of the fires are still burning.
Climate change and wildfires
Most of the fires in Australia ignited due to natural causes, but like other major wildfires in recent years, they’ve been exacerbated by climate change.
Rising concentrations of carbon dioxide in the atmosphere cause Earth’s temperature to rise, which leads to more hot and dry weather, longer droughts, and higher rates of evaporation. Those conditions raise the risk of wildfires.
The problem is not limited to Australia, of course: California experienced its worst wildfire season ever in 2018, and wildfires in Siberia last year razed more than 6.5 million acres (about 26,000 square kilometers).
Wildfires also further contribute to climate change by sending more greenhouse gases into the atmosphere.
Richard Betts, a professor of geography at Exeter University, told The Guardian that extreme events like the Australian bushfires will likely become commonplace if the world’s temperature rises 3 degrees Celsius above pre-industrial levels. Already, Australia’s average temperature has risen about 1.4 degrees, compared to the global average of 1.1 degrees.
“We are seeing a sign of what would be normal conditions in a 3C world. It tells us what the future world might look like,” Betts said.