When tech entrepreneur Paul Allen returned from a diving trip to Mauritius, he was not a happy man.

The billionaire Microsoft co-founder was an avid diver, and had been privileged to visit some of the best dive sites in the world. But his October 2017 visit to the Indian Ocean coincided with the third and largest global coral bleaching. He saw up close the devastation that was caused, triggered by a warming planet.

“Paul had a deep love of the oceans; he would say that being underwater was one of his favourite places in the world,” says Lauren Kickham, director of impact at Vulcan Inc, which Allen established in 1986 to oversee his business and philanthropic interests.

“After a trip to one of his favourite dive sites, when there had been no coral left, he tasked us with saving the world’s coral reefs.”

Allen, who was first diagnosed with Hodgkin lymphoma in 1982, died last year at the age of 65. But his dream of saving the planet’s coral wasn’t forgotten.

A team of satellite mappers, marine scientists and naturalists began mapping and monitoring all the world’s reefs – resulting in the Allen Coral Atlas. At a recent presentation in Seattle, they revealed that while they had tracked just 2 per cent of the world’s coral, they hoped to have completed the task by the end of 2020.

Coral reefs: Trying to combat climate change damage Show all 25 1 /25 Coral reefs: Trying to combat climate change damage Coral reefs: Trying to combat climate change damage Masked Butterflyfish (Chaetodon semilarvatus) swimming over a bommie reef in the Egyptian Red Sea marine reserve of Ras Mohamed, off the southern tip of the Sinai peninsula AFP/Getty Coral reefs: Trying to combat climate change damage Rising sea temperatures cause corals to bleach (go white) and die Getty/iStock Coral reefs: Trying to combat climate change damage A giant clam is seen nestled among coral reefs at the Obhor coast, 30 kms north of the Red Sea city of Jeddah AFP/Gett Coral reefs: Trying to combat climate change damage Coral reef in seychelles that has degraded After the reef has died they break up and become rubble. On this reef there is some regrowth of young corals so there is hope for recovery Getty Coral reefs: Trying to combat climate change damage Coral gardening A rabbitfish in a net H Goehlich Coral reefs: Trying to combat climate change damage A school of fish and a sea can in a healthy coral reef off the coast of Isla Mujeres, Mexico Getty/Lumix Coral reefs: Trying to combat climate change damage Sky views of great barrier reef in Australia Getty/iStock Coral reefs: Trying to combat climate change damage A fish swims among coral reefs at the Obhor coast AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving in the Red Sea AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A rope nursery Nature Seychelles Coral reefs: Trying to combat climate change damage Fish swimming off the coast of Egypt's Red Sea resort of Hurghada. The rebounding tourism sector is worrisome for the fragile marine ecosystem AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A parrotfish on the reef C Reveret Coral reefs: Trying to combat climate change damage Gorgonian sea fan on a a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage A diver swims during a Great Barrier Reef experience on Lady Elliot Island, Australia Getty/Tourism Queensland Coral reefs: Trying to combat climate change damage Jessica Bellsworthy, a PhD student conducting research on the coral reefs of the Gulf of Eilat, holds a coral in an aquarium at the Interuniversity Institute for Marine Sciences in Eilat AFP/Getty Coral reefs: Trying to combat climate change damage Coral reefs in the water off the Obhor coast, 30 kms north of the Red Sea city of Jeddah in 2008 AFP/Getty Coral reefs: Trying to combat climate change damage A diver photographs golden anthias (Pseudanthias aurulentus) on a coral reef in the Egyptian Red Sea marine reserve of Ras Mohamed AFP/Getty Coral reefs: Trying to combat climate change damage FUNAFUTI, TUVALU - AUGUST 15: From the air the ocean (L) and the logoon (R) and separated by a thin stip of land on August 15, 2018 in Funafuti, Tuvalu. The small South Pacific island nation of Tuvalu is striving to mitigate the effects of climate change. Rising sea levels of 5mm per year since 1993, well above the global average, are damaging vital crops and causing flooding in the low lying nation at high tides. Sea water rises through the coral atoll on the mainland of Funafuti and inundates taro plantations, floods either side of the airport runway and affects peoples homes. The nation of 8 inhabited islands with an average elevation of only 2m above sea level is focusing on projects to help it and its people have a future. Four of the outer islands are 97% solar energy dependent and the Tuvalu Government is working to achieve 100% renewable energy from wind and solar by 2025. Tuvalu's 11,000 inhabitants see the effects of climate change in their daily life. (Photo by Fiona Goodall/Getty Images for Lumix) Fiona Goodall Getty/Lumix Coral reefs: Trying to combat climate change damage A photo taken on April 4, 2019 shows fish swimming off the coast of Egypt's Red Sea resort of Hurghada. - In dazzling turquoise waters off Egypt's Red Sea coast, scuba divers swim among delicate pink jellyfish and admire coral -- but the rebounding tourism sector is worrisome for the fragile marine ecosystem. (Photo by Mohamed el-Shahed / AFP) (Photo credit should read MOHAMED EL-SHAHED/AFP/Getty Images) MOHAMED EL-SHAHED AFP/Getty Coral reefs: Trying to combat climate change damage Coral gardening A damselfish Sarah Frias-Torres Coral reefs: Trying to combat climate change damage Divers swim past a coral reef in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage A puffer fish hovering above coral in the Egyptian Red Sea marine reserve AFP/Getty Coral reefs: Trying to combat climate change damage Researchers from the Interuniversity Institute for Marine Sciences in the southern Israeli resort city Eilat monitor coral growth while scuba diving on June 12, 2017 in the Red Sea off Eilat. Global warming has in recent years caused colourful coral reefs to bleach and die around the world -- but not in the Gulf of Eilat, or Aqaba, part of the northern Red Sea. At the Interuniversity Institute for Marine Sciences in southern Israeli resort city Eilat, dozens of aquariums have been lined up in rows just off the Red Sea shore containing samples of local corals AFP/Getty Coral reefs: Trying to combat climate change damage This photo taken on April 21, 2017 shows an aerial shot of part of mischief reef in the disputed Spratly islands on April 21, 2017. Philippine Defence Secretary Delfin Lorenzana flew to a disputed South China Sea island on April 21, brushing off a challenge by the Chinese military while asserting Manila's territorial claim to the strategic region. / AFP PHOTO / TED ALJIBE (Photo credit should read TED ALJIBE/AFP/Getty Images) TED ALJIBE AFP/Getty Coral reefs: Trying to combat climate change damage fish swimming off the coast of Egypt's Red Sea resort of Hurghada AFP/Getty

The global coral map is updated every day, and uses advances in artificial intelligence to issue alerts when reef health declines. This monitoring system means that when crises hit, such as bleaching or shipwrecks, local authorities and conservationists will be able to act quickly.

“This is game-changing,” says Greg Asner, director of Arizona State University’s centre for global discovery and conservation science. “I’ve been doing this for 25 years. Until two years ago, we would get an image and then we’d unpack it, and spend months and even years trying to determine what was going on on the sea floor.”

He adds: “Now, we’re getting images every day from all over the world in [real] time.”

Asner says there was a recent incident in one of the northern areas of the Marshall Islands where a tanker ran aground, a long way from where the authorities were based in the south.

“The first image of this happening was from our project,” he says. “I had colleagues there, and they took the picture to the environmental agency, and they found that the tanker had spilled a large amount of fuel oil. The process for them was how them to mitigate that. But we had the image, the next day.”

He says anywhere up to a billion people depend directly on coral for their livelihoods, but that even larger numbers benefit from their association with fisheries and the breaking of storm surges.

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A report published earlier this year by the UN about challenges to biodiversity warned that up to a million species were threatened with extinction. It said around one third of reef-forming corals were at risk.

“Biodiversity and nature’s contributions to people are our common heritage and humanity’s most important life-supporting safety net,” warned Sandra Diaz, a renowned Argentine ecologist who co-chaired the report. “But our safety net is stretched almost to breaking point.”

The images used by Asner and others are provided by Planet Labs, a California-based company that operates 120 satellites to provide almost real-time images. The new images provided by the latest generation of satellites – lighter, smaller and cheaper – means Planet Labs can detect deforestation, the growth of cities, sea ice, and even the spread of camps for refugees or internally displaced people.

Andrew Zolli, the company’s vice president of global impact, says the team is fond of saying: “You can’t save something you cannot see.”

“These problems tend to be remote from our everyday experience,” he says.

Paul Allen, here in 2014, was inspired to start a coral project after seeing bleaching firsthand (Getty)

“We hand these data sets to scientists,” Zolli adds. “The challenge is how to turn big data into action.”

The map being produced for the coral atlas will comprise the highest resolution images of the world’s reefs seen so far.

“What we know about the coral reefs is that they are under tremendous stress, specifically from climate change and human development. Yet no high-resolution map of the world’s coral reefs exists,” he says.

“Less than a hundredth of 1 per cent of the world’s reefs are actively monitored for change, and when they are, they’re monitored using methods that would have been familiar to the Wright brothers. People go up in planes and literally estimate the extent of things such as coral bleaching.”

He adds: “We’re using an early 20th-century solution to deal with a global 21st-century problem, and we’re failing at it badly.”

Allen, who died last October and was said to have a fortune of more than $20bn (£16bn) at the time of death, did not have an entirely seamless relationship with the oceans. In January 2016, it was reported that one of his yachts, the 303ft MV Tatoosh, unintentionally destroyed a large part of a coral reef in the Cayman Islands with its anchor chain.

A spokesperson for Vulcan said at the time that Allen was not in the Caribbean when the incident took place, and questioned the reported scale of the damage the accident caused.

A Vulcan spokesperson told The Independent: “It was never determined that the coral injury in the Cayman Islands was caused by the Tatoosh, as there was a long history of incidents in that location. Regardless, in 2016, Vulcan quickly commissioned leading experts in coral and reef restoration to rebuild, protect and preserve the local ecosystem for generations to come.”

Helen Fox has the task of using the data produced by the Allen-inspired project and working with local communities. She says sometimes they are able to piggyback on existing projects; sometimes they start new initiatives.

They also work with conservationists and students to dive and take images pegged to a GPS tracker, to help validate the maps produced the satellites.

Fox, a senior director at the National Geographic Society, says the goal “is to have a network of engaged users who can receive alerts if there are bleaching events or ship groundings”.

She says the unique aspect of the project is the speed with which it provides images, matched with its global scale.