Percent of Coral Reefs Left Globally
CURRENT TOTAL
Live Counter Notable Facts
(Data shown in the table is for 2025. Counter shows current estimate)
Reefs Remaining
Annual Loss Rate
Projected by 2050
Understanding Percent of Coral Reefs Left Globally
This counter displays the declining percentage of healthy coral reefs remaining globally. Since the 1950s, the world has lost approximately 50% of its coral reef coverage, with 14% lost just between 2009-2018. The current rate of decline threatens the survival of these critical ecosystems.
Coral reefs, often called the 'rainforests of the sea,' cover less than 1% of the ocean floor but support approximately 25% of all marine species. The ongoing loss is primarily driven by climate change, with marine heatwaves causing mass bleaching events that have affected over 80% of global reefs.
Without drastic action to limit global warming to 1.5°C, scientists predict 70-90% of coral reefs will disappear by 2050. At 2°C of warming, 99% of coral reefs face extinction. The fourth global bleaching event (2023-2025) has already impacted 84% of the world's reefs across 82 countries.
Global Coral Reef Crisis Overview
- The planet has lost half of its coral reefs since the 1950s, with coral-associated biodiversity dropping by 63%. This catastrophic decline represents one of the most visible impacts of climate change on marine ecosystems, affecting both ecological function and human communities.
- Rising ocean temperatures are the primary driver of coral decline. The 2014-2017 global bleaching event was the longest and most destructive on record, affecting 75% of global reefs. The current fourth global bleaching event, ongoing since 2023, has required new alert levels to indicate unprecedented mortality risk.
- Coral reefs provide over $3.4 billion in annual economic value to the U.S. alone through fisheries, tourism, and coastal protection. Globally, one billion people benefit from reef ecosystem services, with reefs protecting coastlines by absorbing up to 97% of wave energy.
- Recovery is possible but requires immediate action. Some reefs have shown resilience and ability to recover when stressors are reduced. However, the window for action is rapidly closing - at current rates, functional coral reef ecosystems may cease to exist within our lifetime.
Coral Reef Terminology
- Coral Bleaching: The expulsion of symbiotic algae (zooxanthellae) from coral tissues due to stress, causing corals to turn white and potentially die
- Reef Resilience: The ability of coral reef ecosystems to resist, recover from, and adapt to disturbances while maintaining key functions
- Ocean Acidification: The decrease in ocean pH caused by absorption of carbon dioxide, making it harder for corals to build calcium carbonate skeletons
- Refugia: Areas where coral reefs may survive future climate change due to local conditions providing protection from heat stress
Historical Coral Loss Timeline
- 1950s Baseline: 100% (estimated historical coverage)
- 1998 First Global Bleaching: 16% of reefs affected
- 2010 Second Global Bleaching: 37% of reefs impacted
- 2014-2017 Third Event: 75% experienced heat stress
- 2023-2025 Fourth Event: 84% affected (ongoing)
- 2050 Projection: Only 10-30% may remain
Regional Reef Status
- Caribbean: 80% decline since 1970s
- Great Barrier Reef: 50% coral cover lost since 1995
- Indian Ocean: 69-99% bleached in some areas
- Pacific Islands: Variable, 20-80% affected
- Red Sea: Relatively resilient but under threat
- Southeast Asia: 95% at risk from human activities
Temperature Thresholds
- Current Warming: 1.1°C above pre-industrial
- 1.5°C Warming: 70-90% of reefs lost
- 2.0°C Warming: 99% of reefs lost
- Safe Threshold: <1°C already exceeded
- Bleaching Trigger: 1°C above summer maximum
- Recovery Time Needed: 10-15 years between events
Data Sources and References
Methodology and Data Collection
Coral reef coverage estimates are based on satellite monitoring, in-water surveys, and historical records compiled by GCRMN, NOAA, and research institutions across 100+ countries monitoring over 12,000 reef sites.
The counter shows 50% of reefs remaining based on cumulative losses since the 1950s baseline, with ongoing decline of 1-2% annually. This reflects both permanent reef loss and severely degraded reefs that have lost ecological function.