Photo taken on Dec. 17, 2019 shows the smoke-shrouded Lake Burley Griffin in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)

Photo taken on Dec. 17, 2019 shows the smoke-shrouded National Arboretum in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)

Photo taken on Dec. 17, 2019 shows the smoke-shrouded street in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)

Photo taken on Dec. 17, 2019 shows the smoke-shrouded Australian War Memorial in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)

Photo taken on Dec. 17, 2019 shows the smoke-shrouded National Arboretum in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)

Photo taken on Dec. 17, 2019 shows the smoke-shrouded National Arboretum in Canberra, Australia. Air pollution caused by bushfires continues in Canberra. (Photo by Chu Chen/Xinhua)