Warm ocean waters that sucked the color and vigor from sweeping stretches of the world’s greatest expanse of corals last month were driven by climate change, according to a new analysis by scientists, who are warning of worse impacts ahead.

Climate change made it 175 times more likely that the surface waters of the Coral Sea, which off the Queensland coastline is home to Australia’s Great Barrier Reef, would reach the record-breaking temperatures last month that bleached reefs, modeling analysis showed.

The scientists found March Coral Sea temperatures are likely to be 1.8 degrees F (1 degrees C) warmer now than before humans polluted the atmosphere. Temperatures recorded by the Australian government last month were slightly higher than that, in part because of a fierce El Niño.