Science

Global Coral Reef Collapse Timeline 1980–2030: Bleaching, Heatwaves & the Shrinking Recov…

Global coral reefs have lost about 9.5% of hard-coral cover relative to their 1980-2009 average, according to the GCRMN's 2025 global assessment released 31 Au…

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REFERENCE PERIOD

GCRMN Reference Period: 30.2% Average Global Hard-Coral Cover

GCRMN uses 1980-2009 as its monitoring reference period, with an estimated average global hard-coral cover of 30.2%. This is a monitoring baseline, not an untouched pre-…

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FIRST GLOBAL EVENT

First Global Coral Bleaching Event

A major El Nino drove extreme ocean heat, producing the first event recognised as a global coral bleaching event. NOAA estimates roughly 21% of global reef area was expo…

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SECOND GLOBAL EVENT

Second Global Coral Bleaching Event

A strong El Nino year contributed to widespread ocean heat, exposing an estimated 37% of global reef area to bleaching-level stress. GCRMN's current analysis associates…

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THIRD GLOBAL EVENT

Third Global Coral Bleaching Event: a Three-Year Crisis

Bleaching-level heat stress affected an estimated 68.2% of global reef area over this multi-year event, which included back-to-back bleaching on the Great Barrier Reef i…

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PROOF OF RECOVERY

Global Hard-Coral Cover Recovers ~6% After the Third Event

In the two years following the 2014-2017 event, global average hard-coral cover rose by roughly 6% relative - the clearest evidence in the modern record that coral reefs…

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FOURTH & LARGEST EVENT

Fourth Global Coral Bleaching Event: 84.4% of Reef Area Exposed

Confirmed by NOAA on 15 April 2024, this became the largest global bleaching event on record. From January 2023 through September 2025, bleaching-level heat stress affec…

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GREAT BARRIER REEF: LOSS TH…

Great Barrier Reef Records Sharp Losses, Then Shows Early Recovery

AIMS's 2025 survey found northern GBR hard-coral cover falling from 39.8% to 30.0% (its largest annual decline on record), central cover falling from 33.2% to 28.6%, and…

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NEW GCRMN GLOBAL REPORT

GCRMN Releases "Status of Coral Reefs of the World: 2025"

Released 31 August 2026, this is GCRMN's most comprehensive global assessment yet: 21.1 million observations from 87,299 surveys at 36,886 reef sites across 124 countrie…

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POLICY CHECKPOINT

2030: A Climate and Biodiversity Policy Checkpoint

2030 is not a coral-extinction date. It is the target year in IPCC's 1.5C-aligned emissions pathways (roughly 43% below 2019 levels) and in the Kunming-Montreal Global B…

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