General view of Chilean Calbuco volcano from Puerto Montt, located at 1000 km southern Santiago de Chile, Chile, 22 April 2015. Due to the eruption of the volcano with a smoke column 20 km high, authorities declared a red alert and ordered the evacuation of around 1500 inhabitants of Ensenada, Alerce, Colonia Río Sur and Correntoso towns. (Photo by Alex Vidal Brecas/EPA)

Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

Revellers hit the town on Saturday, February 19, 2022 for a pub crawl despite the snow in Leeds, United Kingdom. The UK capital was placed under its first ever “red” weather warning, meaning there is “danger to life”. The same level of alert was in place across southern England and South Wales, where schools were closed and transport paralysed. (Photo by Nb press ltd)

Popocatepetl volcano spews incandescent material as seen from Paso de Cortés on May 23, 2023 in Amecameca, Mexico. The second highest volcano in the country increased its activity while Mexican authorities raised the alert to yellow phase 3. Popocatepetl volcano caused the fall of ashes in different municipalities in Puebla, Estado de Mexico and Mexico City. Mexican army has spread forces as a preventive measure while the 3 levels of government are in coordination to observe the activity of the volcano and the situation in the surroundings. (Photo by Cristopher Rogel Blanquet/Getty Images)

A firefighter is seen next to flames while working to extinguish a wildfire burning in Gondomar, northern Portugal on July 29, 2025. Almost 2,000 firefighters battled on July 29, 2025 to contain forest blazes across Portugal that have led to almost the whole country being put on high alert for fires. Ten major fires blazed with two in the north and three in the centre of the country causing most concern. (Photo by Carlos Costa/AFP Photo)

Two Brits enjoy Saturday night in Leeds, United Kingdom in bank holiday on May 1, 2021, as number of coronavirus cases and deaths keep decreasing in the UK. The government today reported seven new coronavirus deaths and a further 1,907 infections. (Photo by Nb press ltd)

A couple wears face masks as they share a moment during sunset on January 31, 2020 in Hong Kong, China. With over 9800 confirmed cases of Novel coronavirus (2019-nCoV) around the world, the virus has so far claimed over 200 lives. (Photo by Anthony Kwan/Getty Images)

A resident (unseen) uses a belt to get vegetables in Wuhan, in China's central Hubei province on March 13, 2020. China reported just eight cases of the coronavirus on March 13, with no new domestic infections outside the epicentre of Hubei province. (Photo by AFP Photo/China Stringer Network)