Carl de Keyzer has been keeping busy with his new project on Europe’s coastline – all 500,000km of it. “It’s about the threat from rising sea levels,” explains the Belgian photographer, who has been a full-time member of Magnum Photos since 1994. “But it’s also about composition, people and light. I always used to work with the past, making work about people confronted by a system larger than themselves. Now I’m working with the future, and nature is the biggest system of all.”

The idea for this latest five-year project came to him after a commission from the concert house in Bruges. “They wanted water, for a water-themed concert season, so I went to beaches in Belgium. That’s how the whole thing started. Walking on the beach gave me the idea to expand the project, especially with the issue of global warming so prevalent. I’ve always loved the coast. My first book when I was 20 was on the Belgian coastline. It was a mixture in style between Elliot Erwitt and Tony Ray-Jones.”

Click on an image on de Keyzer’s social-media-savvy website he set up for the project and you can zoom in to look at extreme detail. One image shows eroded cliffs in Easington near Hull, and zooming in feels like you’re practically sniffing the sandstone earth. “I wanted to add an exhibition experience to the website. I love playing with reality. You go to an exhibition, you see the prints, then you go closer.”

On the site he explains the genesis of the project as “an investigation into how Europe is coping with the difficult-to-gauge threat” of climate change without ever slipping into political grandising. “The coast is the question mark of the mainland. And that’s what makes it so fascinating a subject for photographic research that tries to depict uncertainty.”

De Keyzer puts images online one or two days after he’s shot them and a link to Google Earth lets you see exactly where the image was taken. Another link leads to a blog where you can read his ongoing comments on the project. It all makes for a highly interactive experience. “At first people were very critical and I was shocked,” he laughs. “For me that was new because usually I work three years on a project before the book and the exhibition come out, and nobody will have seen anything in terms of work-in-progress.”

And there’s an added benefit for de Keyzer. “People are starting to give me really good hints for places,” he says, “and they’re sending me pictures, which is great as I can put it on my list of where to go. Now it’s really happening while I shoot.” People can also download the images with no fee, but have to ask permission to publish them. “I want to share things,” says de Keyzer. “I’m a big believer in showing them to more people, and I think the end result economically will be more positive. The whole project is about communicating.”

He has already photographed three coastlines out of a total of 10 European countries – Belgium, Holland and the UK. This year he’ll be travelling to warmer climes in France, Spain and Portugal, and in the winter will visit Scandinavian countries before finishing off next year in Italy and Greece.

“The project will be completed in 2012, which is significant because the Mayans predicted it would be the end of the world,” Keyzer says half tongue-in-cheek. Climate change is particularly pertinent at the moment following the failure of the Copenhagen climate conference to agree a successor to the Kyoto protocol for beyond 2012. “On the news I see people getting afraid,” he observes. “It might be a major disaster in 50 years, or it could go away. I don’t know. But I tend to belong to the side of ‘let’s do something about it now’. Maybe we have to start losing beaches before anything’s done.”

From the outset, de Keyzer shot High Dynamic Range (HDR) images, combining different exposures to form one single image. “I wanted to get the last image before it turns to hell. It’s more like the ‘before’ moment, with the atmosphere of a big threat coming our way,” he explains. “For me HDR is just a practical way to get the high contrast in. But it adds to the atmosphere of something coming from the sea that doesn’t look good. I’m shooting on a 60‑megapixel Phase One P65+ back, either hand-held or on a tripod, and I combine the images in Photoshop. The P65+ is just a tool for making landscape images that are incredibly sharp. It’s like running around with an 10 x 8 camera hand-held.”

But de Keyzer’s technique is evolving as the project progresses. “Now I’m doing more hand-held and I’m finding I can get the same result from just one image, which is better for shooting people. The P65+ has 12-and-a-half stops dynamic range, which is incredible.” His subject matter is also changing. “At first I didn’t include people, but now I’m starting to. Now the project is beginning to look like my older pictures, less [surreal] HDR, but the idea is to combine the two atmospheres. I don’t have to revisit the locations either, I just go back to the first images in Photoshop.”

The theme of communication is important, as one of de Keyzer’s sponsors is telecommunications giant Orange. “Magnum Paris arranged that and for the first time in my life I have sponsorship.” Orange’s sponsorship adds another dimension to his project: GPS positioning. “I have two assistants in Paris, who are also paid by Orange,” de Keyzer explains. “They go round the entire European coastline, they check every half-mile, and when they see something that could be interesting for me, they put up a flag. I then go to the place with my GPS. I’m depending on these people to show me the way, because I can only visit five locations a day. In the UK I did that every day over seven weeks. That’s 250 locations. There are more than 20 countries in Europe with coastlines!” he adds, stressing how large the task is that lies before him.

Despite the enormity of the project, de Keyzer’s end-goal is to have an exhibition and a book, with around 200 pages. “For that, all I need is five to 10 good, strong images from each country.”