Three-quarters of the world's coral reefs are at risk from overfishing, pollution and climate change, according to a report.

By 2050 virtually all of the world's coral reefs – from the waters of the Indian Ocean to the Caribbean to Australia – will be in danger, the report warns. The consequences – especially for countries such as the Philippines or Haiti which depend on the reefs for food – will be severe.

"These are dire results," said Lauretta Burke, a lead author of Reefs at Risk, a collaborative effort led by the World Resources Institute in Washington and 25 other research organisations.

The reefs of south-east Asia are in the most acute peril – with 95% on the danger list; 75% of the reefs in the Caribbean are also threatened, including all those in Florida, Haiti and Jamaica. But even Australia, where reefs are protected, will be in the danger zone by the middle of the century if climate change is left unchecked.

Jane Lubchenco, who heads the National Oceanic and Atmospheric Administration, described the scenario as a "perfect storm" of global and local threats. "Make no mistake. This is a critical time for ocean eco-systems in general but especially for coral reefs," she said.

Burke and other experts at the release of the report in Washington said the assault could be reversible. "Coral reefs are resilient and do rebound from these pressures when local threats are kept low," Burke said.

But Lubchenco warned: "It will take a Herculean effort to reverse the current trajectory and leave a healthy ecosystem to our children and grandchildren."

The most immediate threat to reefs is overfishing, which has put about half of the world's reefs in peril. In the Indian and Pacific Oceans the danger is particularly acute, because of overfishing and extreme methods which use dynamite and other explosives to blast fish out of the water.

The loss of reefs owing to overfishing could be devastating for countries in south-east Asia and the Caribbean, which depend heavily on coral for tourist revenue and food. Some 275 million people live within 30km of reefs, the report says.

Other threats include pollution, from industrial and agricultural development. But, in the 13 years since scientists took their last in-depth look at reefs, climate change has posed a growing danger.

Warming seas cause coral bleaching by killing the tiny creatures that nourish reefs and give corals their colour. Eventually the reefs die.

The basic chemistry of the oceans is also changing, because of increased concentrations of carbon dioxide in the atmosphere.

Those changes, known as ocean acidification, make it difficult for the coral to harden and form reefs. By 2050 only about 15% of the world's coral will be in waters where the conditions are right for growth.

According to current climate projections, roughly half of the world's reefs will experience coral bleaching by 2030 – and nearly 95% by 2050. Reefs could recover from relatively mild bleaching, but severe stress will be irreversible.

The combined effects of climate change will overwhelm even the most dedicated conservation efforts, such as in Australia where about 85% of reefs are protected from fishing.

"If we do want to have reefs around by 2050 we are going to have to do something about carbon dioxide," said Nancy Knowlton, chair of marine sciences at the Smithsonian.