Birds fly next to electricity pylons on a smoggy afternoon in the old quarters of Delhi, India, October 30, 2019. REUTERS/Adnan Abidi

Birds fly next to electricity pylons on a smoggy afternoon in the old quarters of Delhi, India, October 30, 2019. REUTERS/Adnan Abidi TPX IMAGES OF THE DAY

A man carrying a basket walks along the paddy fields early in the morning in Bhaktapur, Nepal, October 27, 2019. REUTERS/Monika Deupala

Olive trees stand in a grove in Porcuna, southern Spain October 15, 2019. Picture taken October 15, 2019. REUTERS/Marcelo del Pozo

A view of Beppu from the Beppu Bay Service Area, Japan, October 14, 2019. REUTERS/Peter Cziborra

Fog rises over a village in the mountainous district of Haraz, around 90 kilometers southwest of Sanaa, Yemen October 2, 2019. Picture taken October 2, 2019. REUTERS/Khaled Abdullah

A village is shrouded by fog in the mountainous district of Haraz, around 90 kilometers southwest of Sanaa, Yemen October 2, 2019. Picture taken October 2, 2019. REUTERS/Khaled Abdullah

Fog rises above a village in the mountainous district of Haraz, around 90 kilometers southwest of Sanaa, Yemen October 2, 2019. Picture taken October 2, 2019. REUTERS/Khaled Abdullah

A general view of the urban landscape of Tel Aviv as most Israeli Jews refrain from driving during the 25-hour period of Yom Kippur, Israel October 9, 2019. REUTERS/Ammar Awad

A morning fog is seen in the Siberian city of Omsk, Russia October 8, 2019. Picture taken October 8, 2019. REUTERS/Alexey Malgavko TPX IMAGES OF THE DAY

People are seen through a window as waves hit the coast of Sao Mateus, as Hurricane Lorenzo hits the Azores islands, in Azores, Portugal October 2, 2019. REUTERS/Rafael Marchante TPX IMAGES OF THE DAY

People are seen ahead of Pope Francis' arrival for a prayer vigil with youth at the Soamandrakizay Mess site in Antananarivo, Madagascar, September 7, 2019. REUTERS/Yara Nardi

Men walk along a street on a foggy morning in the old quarters of Delhi, India, December 31, 2018. REUTERS/Anushree Fadnavis TPX IMAGES OF THE DAY

A frosty trees are seen at the air temperature at about -28 degrees Celsius near the Siberian village of Ust-Mana outside Krasnoyarsk, Russia December 27, 2018. REUTERS/Ilya Naymushin

A man paddles a handmade boat across the Yamuna river on a foggy winter morning in New Delhi, India December 27, 2018. REUTERS/Adnan Abidi TPX IMAGES OF THE DAY

Men paddle their handmade boats across the Yamuna river on a foggy winter morning in New Delhi, India December 27, 2018. REUTERS/Adnan Abidi

A man paddles a handmade boat across the Yamuna river on a foggy winter morning in New Delhi, India December 27, 2018. REUTERS/Adnan Abidi

Windows take on different shapes as they reflect upon the water along a wharf in Portland, Maine, U.S., December 24, 2018. REUTERS/Kevin Lamarque TPX IMAGES OF THE DAY

Thousands of starlings fly in a 'murmuration' as they return to roost at dusk near Ely in Cambridgeshire, Britain December 24, 2018. REUTERS/Hannah McKay TPX IMAGES OF THE DAY

A man feeds seagulls as he stands on the banks of Yamuna river on a foggy winter morning in New Delhi, India, December 24, 2018. REUTERS/Adnan Abidi TPX IMAGES OF THE DAY

The sunset is seen during a poor air quality day in Bangkok, Thailand, December 21, 2018. REUTERS/Jorge Silva TPX IMAGES OF THE DAY

A man walks through a vegetable field on a foggy winter morning in New Delhi, India, December 18, 2018. REUTERS/Anushree Fadnavis TPX IMAGES OF THE DAY

A man walks through a vegetable field on a foggy winter morning in New Delhi, India, December 18, 2018. REUTERS/Anushree Fadnavis

Smog is seen near transmission towers in Bedzin, near Katowice, Poland, December 5, 2018. REUTERS/Kacper Pempel

Smog is seen in this general view of the Upper Silesian Industrial Region from Bedzin, near Katowice, Poland, December 5, 2018. REUTERS/Kacper Pempel

Smog is seen during sunset in this general view of the Upper Silesian Industrial Region from Bedzin, near Katowice, Poland, December 5, 2018. REUTERS/Kacper Pempel

Smog is seen during sunset in this general view of the Upper Silesian Industrial Region from Bedzin, near Katowice, Poland, December 5, 2018. REUTERS/Kacper Pempel

Smog is seen in this general view of the Upper Silesian Industrial Region from Bedzin, near Katowice, Poland, December 5, 2018. REUTERS/Kacper Pempel

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3,2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

General view of the city as smog blankets Sarajevo, Bosnia and Herzegovina December 3, 2018. Picture is taken December 3, 2018. REUTERS/Dado Ruvic

People walk on a pedestrian bridge as heavy smog blankets China's capital after the city issued its first air pollution alert for the winter season, in Beijing, China November 26, 2018. REUTERS/Jason Lee TPX IMAGES OF THE DAY

People walk on a pedestrian bridge as heavy smog blankets China's capital after the city issued its first air pollution alert for the winter season, in Beijing, China November 26, 2018. REUTERS/Jason Lee

Protesters wearing yellow vests, a symbol of a French drivers' protest against higher fuel prices, are seen during riots on the Champs-Elysees in Paris, France, November 24, 2018. REUTERS/Gonzalo Fuentes

Clouds can be seen above a dust storm as it descends upon the city of Sydney in Australia, November 22, 2018. Picture taken through the window. REUTERS/David Gray

Snow covered trees are seen on a foggy day in the Buda hills in Budapest, Hungary, November 19, 2018. REUTERS/Bernadett Szabo

People walk on a foggy day in the Buda hills in Budapest, Hungary, November 19, 2018. REUTERS/Bernadett Szabo

Snow covered trees are seen on a foggy day in the Buda hills in Budapest, Hungary, November 19, 2018. REUTERS/Bernadett Szabo

Snow covered trees are seen on a foggy day in the Buda hills in Budapest, Hungary, November 19, 2018. REUTERS/Bernadett Szabo

Snow covered trees are seen on a foggy day in the Buda hills in Budapest, Hungary, November 19, 2018. REUTERS/Bernadett Szabo

Heavy fog covers the city of Minsk, Belarus November 9, 2018. REUTERS/Vasily Fedosenko TPX IMAGES OF THE DAY

Heavy fog covers the city of Minsk, Belarus November 9, 2018. REUTERS/Vasily Fedosenko

Heavy fog covers the city of Minsk, Belarus November 9, 2018. REUTERS/Vasily Fedosenko

Heavy fog covers the city of Minsk, Belarus November 9, 2018. REUTERS/Vasily Fedosenko

Heavy fog covers the city of Minsk, Belarus November 9, 2018. REUTERS/Vasily Fedosenko

Sunlight reflects from windows of an apartment building on a foggy autumn day in Kiev, Ukraine November 8, 2018. REUTERS/Valentyn Ogirenko TPX IMAGES OF THE DAY

Sunlight reflects from windows of an apartment building on a foggy autumn day in Kiev, Ukraine November 8, 2018. REUTERS/Valentyn Ogirenko TPX IMAGES OF THE DAY

Sunlight reflects from windows of an apartment building on a foggy autumn day in Kiev, Ukraine November 8, 2018. REUTERS/Valentyn Ogirenko TPX IMAGES OF THE DAY

A bird flies in a front of an orthodox church on a foggy autumn day in Kiev, Ukraine November 8, 2018. REUTERS/Valentyn Ogirenko

Sunlight reflects from windows of an apartment building on a foggy autumn day in Kiev, Ukraine November 8, 2018. REUTERS/Valentyn Ogirenko

A man with his face covered walks in front of the India Gate amidst smog in the early morning in New Delhi, India, November 8, 2018. REUTERS/Anushree Fadnavis TPX IMAGES OF THE DAY

A man wearing a protective mask walks amidst smog in the early morning in New Delhi, India, November 8, 2018. REUTERS/Anushree Fadnavis

Buildings are seen shrouded in smog in New Delhi, India, November 8, 2018. REUTERS/Anushree Fadnavis

A man crosses a road on a smoggy morning in New Delhi, India, November 8, 2018. REUTERS/Anushree Fadnavis

A Georgia State Patrol Officer guards the ballroom at Republican gubernatorial candidate Brian Kemp's election night party in Athens, Georgia, U.S. November 6, 2018. REUTERS/Chris Aluka Berry TPX IMAGES OF THE DAY