From the forests, to the oceans… The climate crisis concerns everyone and it is happening fast. The big changes are reflected – among others – in the extent of coral reefs.

The image on Australia’s Great Barrier Reef is illustrative. These waters surrounding Lady Elliot Island, off the east coast of Australia, are at the forefront of the climate crisis, as one of the first places to suffer from white coral colonies that have now spread around the world.

The Great Barrier Reef just experienced its worst summer on record, and the US-based National Oceanic and Atmospheric Administration (NOAA) announced last month that the world was experiencing a rare global coral bleaching event – the fourth since the end of the decade 1990 – affecting at least 53 countries.

Historical records in the last year

Corals are victims of rising global temperatures that have broken historical records in the last year. This situation was mainly caused by fossil fuels increasing carbon emissions and accelerated by the El Niño weather pattern, which warms ocean temperatures.

The coral bleaching phenomenon was recorded on five different reefs spanning the northern and southern part of the ecosystem over an area of ​​2,300 km.

“What’s happening in our oceans right now is like underwater fires,” said Kate Quigley, principal investigator at Australia’s Minderoo Foundation. “We will have so much warming that we will reach a tipping point and we will not be able to come back from it,” he added.

Bleaching occurs when sea heat stresses corals, forcing them to expel algae from their tissue, draining their color. Corals can recover from bleaching if temperatures return to normal, but will die if the water remains warmer than usual.

“It’s a disaster…”

“It’s a disaster,” said Professor Ove Hoegh-Guldberg, a climate scientist at the University of Queensland in Australia and chief scientist at The Great Barrier Reef Foundation. “The temperatures got so hot, it’s off the charts … it’s never happened before at this level,” he says.

Destruction of marine ecosystems is equivalent to a death sentence for a quarter of all reef-dependent species and will threaten an estimated one billion people who rely on reef fish for food and livelihoods. Reefs also provide vital protection for coastlines, reducing the effects of floods, cyclones and sea-level rise.

“Humanity is being threatened at a rate that I’m not sure we really understand,” Hoegh-Guldberg said.