A plane leaves behind contrails as it flies in the sky over Paris, France, April 24, 2020. REUTERS/Charles Platiau

A plane leaves behind contrails as it flies in the sky over Paris, France, April 24, 2020. REUTERS/Charles Platiau

The Bossons glacier in the Mont-Blanc massif is pictured on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse

The Aurora Borealis (Northern Lights) is seen in the sky in Ivalo of Lapland, Finland September 27, 2019. Picture taken September 27, 2019. REUTERS/Alexander Kuznetsov

The Aurora Borealis (Northern Lights) is seen in the sky in Ivalo of Lapland, Finland September 27, 2019. Picture taken September 27, 2019. REUTERS/Alexander Kuznetsov TPX IMAGES OF THE DAY

The Aurora Borealis (Northern Lights) is seen in the sky in Ivalo of Lapland, Finland September 27, 2019. Picture taken September 27, 2019. REUTERS/Alexander Kuznetsov

The Aurora Borealis (Northern Lights) is seen in the sky in Ivalo of Lapland, Finland September 27, 2019. Picture taken September 27, 2019. REUTERS/Alexander Kuznetsov

The Aurora Borealis (Northern Lights) is seen in the sky in Ivalo of Lapland, Finland September 27, 2019. Picture taken September 27, 2019. REUTERS/Alexander Kuznetsov

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton TPX IMAGES OF THE DAY

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after liftoff from the Cape Canaveral Air Force Station, as viewed from 65 miles (around 105 km) away in Kissimmee, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly secure communications. REUTERS/Gregg Newton

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after lift off from the Cape Canaveral Air Force Station in Cape Canaveral, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly-secure communications. REUTERS/Joe Skipper

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after lift off from the Cape Canaveral Air Force Station in Cape Canaveral, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly-secure communications. REUTERS/Joe Skipper

The contrail of a United Launch Alliance Atlas 5 rocket is illuminated by the sun after lift off from the Cape Canaveral Air Force Station in Cape Canaveral, Florida, U.S., August 8, 2019. Aboard is the fifth Advanced Extremely High Frequency (AEHF) satellite, designed to provide the U.S. military with highly-secure communications. REUTERS/Joe Skipper

Cirrus clouds and some contrails that have spread out in the wind streak across the sky above a Red Ensign flag on the ferry MS Oldenburg during the Cloud Appreciation Society's gathering in Lundy, Britain, May 21, 2019. Picture taken May 21, 2019. To match Special Report CLIMATE-CHANGE/BRITAIN-CLOUDS REUTERS/Phil Noble

Cirrus clouds and contrails are seen above the island of Lundy and its 'North Light' lighthouse during the gathering of the Cloud Appreciation Society on Lundy, Britain, May 21, 2019. Picture taken May 21, 2019. To match Special Report CLIMATE-CHANGE/BRITAIN-CLOUDS REUTERS/Phil Noble

Airplanes leave contrails above Half Dome as the sun rises in Yosemite National Park, California, U.S., March 30, 2019. National Park Week begins April 20, 2019. REUTERS/Lucy Nicholson

An aircraft is seen in the sky at Manbij countryside, Syria December 29, 2018. REUTERS/Khalil Ashawi

A view shows the Siberian city of Krasnoyarsk on a foggy frosty day, with the air temperature at about minus 29 degrees Celsius (minus 20.2 degrees Fahrenheit), Russia December 26, 2018. REUTERS/Ilya Naymushin

A contrail is seen as India's Geosynchronous Satellite Launch Vehicle Mk III (GSLV-Mark III) carrying GSAT-29 communication satellite lifts off from the Satish Dhawan Space Centre in Sriharikota, India, November 14, 2018. REUTERS/P. Ravikumar

The Soyuz MS-10 spacecraft carrying the crew of astronaut Nick Hague of the U.S. and cosmonaut Alexey Ovchinin of Russia blasts off to the International Space Station (ISS) from the launchpad at the Baikonur Cosmodrome, Kazakhstan October 11, 2018. REUTERS/Shamil Zhumatov

Passenger planes leave contrails in the sky as they fly over Malta at sunset, as seen from Valletta, Malta September 24, 2018. REUTERS/Darrin Zammit Lupi

Passenger planes leave contrails in the sky as they fly over Malta at sunset, as seen from Valletta, Malta, September 24, 2018. REUTERS/Darrin Zammit Lupi

Passenger planes leave contrails in the sky as they fly over Malta at sunset, as seen from Valletta, Malta, September 24, 2018. REUTERS/Darrin Zammit Lupi

A plane leaves behind contrails as it flies past a waxing crescent moon, Portsmouth, Britain, August 14, 2018. REUTERS/Peter Cziborra

British Aerosparx team performs during the Wings Over Baltics air show in Tukums, Latvia August 4, 2018. REUTERS/Ints Kalnins

A blood moon is seen in the sky over the skyline of Frankfurt as an airplane passes by, Germany, July 27, 2018. Picture taken with long exposure. REUTERS/Kai Pfaffenbach

A plane leaves a vapor trail as it flies past the moon above the town of Gunnedah, New South Wales, Australia July 21, 2018. Picture taken July 21, 2018. REUTERS/David Gray TPX IMAGES OF THE DAY

A plane leaves a vapor trail as it flies past the moon above the town of Gunnedah, New South Wales, Australia July 21, 2018. Picture taken July 21, 2018. REUTERS/David Gray TPX IMAGES OF THE DAY

A plane leaves a vapor trail as it flies past the moon above the town of Gunnedah, New South Wales, Australia July 21, 2018. Picture taken July 21, 2018. REUTERS/David Gray

Aircraft contrails are seen at dawn in the sky above Windsor Castle, the location for the forthcoming wedding of Britain's Prince Harry and his fiancee Meghan Markle, in Windsor, Britain May 18, 2018. REUTERS/Toby Melville

An aircraft contrail is seen before dawn in the sky above Windsor Castle, the location for the forthcoming wedding of Britain's Prince Harry and his fiancee Meghan Markle, in Windsor, Britain May 18, 2018. REUTERS/Toby Melville

Children are seen in silhouette riding a tricycle along the Mississippi River Park at sunset in Baton Rouge, Louisiana, U.S., March 6, 2018. REUTERS/Shannon Stapleton

The contrail of SpaceX's first Falcon Heavy rocket loom above spectators at Cocoa Beach after its launch from the Kennedy Space Center, Florida, U.S., February 6, 2018. REUTERS/Gregg Newton

Seagull flys past the contrail of SpaceX's first Falcon Heavy rocket after it launched from the Kennedy Space Center, Florida, U.S., February 6, 2018. REUTERS/Gregg Newton

Seagulls fly past aircraft contrails light up by the dawn light over London, Britain, January 30, 2018. REUTERS/Toby Melville

Seagulls fly past aircraft contrails light up by the dawn light over London, Britain, January 30, 2018. REUTERS/Toby Melville

A Qatar Airways Boeing 777-2DZ(LR), flying from Sao Paulo in Brazil to Doha in Qatar, is seen at sunset from Dwejra outside the village of San Lawrenz on the island of Gozo, Malta, January 25, 2018. REUTERS/Darrin Zammit Lupi

A Turkish fighter jet flies over the town of Hassa on the Turkish-Syrian border in Hatay province, Turkey January 20, 2018. REUTERS/Osman Orsal

A Turkish fighter jet flies over the town of Hassa on the Turkish-Syrian border in Hatay province, Turkey January 20, 2018. REUTERS/Osman Orsal

A Turkish fighter jet flies over the town of Hassa on the Turkish-Syrian border in Hatay province, Turkey January 20, 2018. REUTERS/Osman Orsal

El Al Israel Airlines Boeing 787-9 Dreamliner coming into land at Heathrow Airport, London, Britain January 10, 2018. Picture taken January 10, 2018. REUTERS/Matthew Childs

A British Airways Airbus A320-232 comes into land at Heathrow Airport, London, Britain January 10, 2018. Picture taken January 10, 2018. REUTERS/Matthew Childs

Passenger planes leave behind contrails as they fly in the skies over London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra TPX IMAGES OF THE DAY

Passenger planes leave behind contrails as they fly in the skies over London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

A passenger plane leaves behind contrails as it flies in the skies over London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

Passenger planes leave behind contrails as they fly in the skies over London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

A passenger plane approaches to land at London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

A passenger plane approaches to land at London Luton Airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

A passenger plane takes off from London Luton airport, Luton, Britain, January 7, 2018. REUTERS/Peter Cziborra

A runner is seen with aircraft contrails in the sky behind at dawn in London Britain September 21, 2017. REUTERS/Toby Melville

The Blanix-team aerobatic gliders performs during the Breitling Airshow in Sion, Switzerland September 16, 2017. REUTERS/Denis Balibouse TPX IMAGES OF THE DAY

Contrails are seen in the sky as a plane flies over London, Britain April 18, 2017. REUTERS/Stefan Wermuth

A plane is illuminated by the rising sun as it flies over the outskirts of Minsk, Belarus March 23, 2017. REUTERS/Vasily Fedosenko

An aircraft leaves contrails as it flies during sunrise over London, Britain December 29, 2016. REUTERS/Stefan Wermuth

Vapour trails from a Lufthansa plane are seen in the sky over the ski resort of Val d'Isere, France, December 1, 2016. REUTERS/Christian Hartmann

Vapour trails from a Swissair plane are seen in the sky over the ski resort of Val d'Isere, France, December 1, 2016. REUTERS/Christian Hartmann