NEW YORK - They can bolster the coastlines, break the force of hurtling waves, provide housing for fish, shellfish, and migrating birds, clean the water, store as much as 5 per cent of the world’s carbon dioxide, and pump oxygen into the ocean, in part making it possible for life on Earth as we know it.

These miracle machines are not the latest shiny tech invention. Rather, they are one of nature’s earliest floral creations: seagrasses. Anchored on the shorelines of every continent except Antarctica, these plants – and they are plants, not algae, that sprout, flower, fruit and go to seed – are one of the most powerful but unheralded climate solutions that already exist on the planet.

Restoring seagrass is one tool that coastal communities can use to address climate change, both by capturing emissions and mitigating their effects, which is among the topics being discussed as leaders in business, science, culture and policy gather Thursday and Friday in Busan, South Korea, for a New York Times conference, “A New Climate.”

Around the world, scientists, nongovernmental organizations and volunteers are working to restore seagrass meadows, if not to their original glory, then to something far more expansive and majestic than the barren, muddy bottoms left behind when they are damaged or destroyed.

In Virginia, parts of Britain and Western Australia, among other places, with the helping hands of committed researchers and citizen scientists alike, seagrass meadows are coming back. They’re bringing with them clearer waters, stabler shores, and animals and other organisms that used to thrive there. And yet, seagrass doesn’t get the attention it deserves, its partisans say.

It’s impossible to know exactly how much seagrass has been lost, because scientists don’t know how much there was to begin with.

Only about 16 per cent of global coastal ecosystems are considered intact, and seagrasses are among the hardest hit. It’s estimated that one-third of seagrass around the world has disappeared in the past few decades, according to Dr Matthew Long, an associate scientist in marine ch...