From 2023 to 2025, coral reefs experienced their fourth global bleaching event

Coral Bleaching

Coral reefs around the world, including the Great Barrier Reef, are undergoing a crisis known as coral bleaching—which threatens both their existence and the ecosystems they support. This comprehensive report from the Australian Museum explores...

How climate change threatens coral reefs, including via warming and acidification

Increasing ocean temperatures disrupt the symbiotic relationship of corals and algae, causing the former to bleach and weaken, and strengthen storms that can destroy reef structures. Higher greenhouse gas emissions increase dissolved carbon dioxide levels in ocean water, triggering a series of reactions that consume carbonate, a key ingredient in coral reef construction.

Explore a world map of coral reefs and the extent of coral bleaching

The Allen Coral Atlas provides imagery of shallow water reefs, along with maps of potential bleaching events, bleaching alert areas, and bleaching hotspots derived from satellite imagery of whitening. Coral reefs are most prevalent in the Indo-Pacific, the Caribbean, the Red Sea, and the tropical coasts of South America and Africa.

The world's largest coral, as seen from space

The world’s largest individual coral colony—measuring over 100 feet wide and 100 feet long—was discovered in the Solomon Islands. This coral is so large it can be seen from space, and is estimated to be between 300 and 500 years old. The coral's size and health provide hope amidst a global coral bleaching crisis, wherein three-quarters of coral reefs have experienced significant bleaching in recent decades. See the photos from space and learn more here.

A simple infographic explaining how coral bleaching works

When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white.

Scientists are using CRISPR to crossbreed heat-resistant corals amid warming reefs

Inside Australia's National Sea Simulator, coral hybrids are genetically engineered to resist the widespread coral bleaching caused by rising global temperatures. Early trials have developed groups with survival rates up to 34 percentage points higher than nonhybrids. (Some readers may experience a paywall.)

Climate tipping points are irreversible changes to Earth's environment

Earth's natural systems have prevented these events—including the mass death of coral reefs, loss of the Amazon rainforest, and shutdown of Atlantic currents—but scientists believe they are unlikely to withstand continued stressors from climate change.

An overview of the Coral Triangle, which contains about 76% of global coral species

Spanning the waters of Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands, and Timor-Leste, the region contains more than 600 coral species and over 2,200 of the world's coral reef fish species. It sustains 120 million people with food and other resources, as well as a $12B yearly tourism industry.

The ocean's ability to store carbon long-term is being hindered by marine heatwaves

More than 4,000 robotic floats with biogeochemical data sensors, including oxygen, pH, nitrate, suspended particles, chlorophyll, temperature, and conductivity, have been deployed as part of the Global Ocean Biogeochemical Array. They have identified changes to ecosystem structure affecting the ocean's ability to transport carbon from surface waters into the deep.

Can coral live in cold water?

Dive deep beyond the sunlit coral reefs, and you'll discover a world of deep-sea corals. This article from the National Oceanic and Atmospheric Administration (NOAA) explores the ecosystems of deep-sea corals found way below the water's surface....

Discover the economic value of coral reefs, which benefit one billion people worldwide

The National Oceanographic and Atmospheric Administration estimates that US commercial and recreational fisheries valued at $200M depend on coral reefs, which provide up to $1.8B in flood protection by absorbing 97% of wave energy. Combined with the benefits from tourism, US coral reefs provide $3.4B in value annually.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

Invasive species are the third biggest threat to Earth's biodiversity

According to the World Wildlife Fund's Living Planet Report 2020, changes in land and sea use account for about half of all recorded threats to the diversity of the planet's species. Species overexploitation is the second-largest proportional threat at 24%, while invasive species make up 13%.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

The total cost of weather and climate disasters from 1980 to 2024 is almost $3T

The NOAA’s Office of Coastal Management tracks the cost of damage, deaths, and other key statistics related to hurricanes and weather disasters. In 2024, there were 27 billion-dollar disasters, each averaging $1.2B more in damage than the prior five-year average.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

Underwater volcanoes significantly contributes to marine extinctions during the Triassic period

An analysis of ocean basins in the Tibetan Plateau helped identify three major periods of volcanism—250-248, 233-231, and 210-208 million years ago—which released significant amounts of greenhouse gases, altering ocean chemistry. The low-oxygen conditions may help explain half of Earth's Triassic extinctions.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Heat-related deaths may have climbed by more than 50% over 20 years

Between 2000 and 2009 one study suggests annual heat deaths averaged around 2,670, but between 2010 and 2020 that figure was likely more than 4,000. Researchers studied 54 million death records from the contiguous US and created mathematical models to arrive at these figures, noting that a combination of aging populations and climate change drove that increase.

Climate models have predicted sea level rise almost perfectly since the 1990s

The rise in sea levels is primarily due to melting ice in Greenland and Antarctica, and predicted levels have been confirmed accurate by satellite observations. Ocean currents influence regional variations in sea level rise, which are expected to accelerate.

The global impacts of the 1877 'super' El Niño and what could result from similar future events

The 1877 El Niño event lasted approximately 18 months, raised temperatures in the Niño 3.4 region of the equatorial Pacific Ocean by 2.7 degrees Celsius (4.86 degrees Fahrenheit) above average, and contributed to a global famine that killed more than 50 million people. Such events are expected to exacerbate drought-related risks to global food security, driving up food prices worldwide. (Some readers may experience a paywall.)

The resulting climate change, not the asteroid impact itself, killed most dinosaurs

Although the Chicxulub impact caused widespread destruction through earthquakes and tsunamis, the subsequent nuclear winter, acid rain, and eventual greenhouse warming drove mass extinction. Roughly 70% of species, including all non-avian dinosaurs, went extinct.

The ozone layer is on track to recover to pre-1980 levels by mid-century

Thanks to the Montreal Protocol, the ozone layer is steadily recovering and, according to a 2022 assessment, is expected to return to 1980 levels by 2040 globally, 2045 over the Arctic, and 2066 over Antarctica.

Nitrous oxide is the third most significant greenhouse gas made by human activities

Emissions of this molecule increased 40% from 1980 to 2020, with atmospheric concentrations reaching levels higher than at any other time in the last 800,000 years, based on ice core records. Its warming potential is 273 times that of carbon dioxide over 100 years and remains in the atmosphere for more than a century, on average.

Since 2022, two-thirds of data centers have been built in water-stressed areas

In residential evaporative cooling systems, 10% of consumed water is lost to evaporation compared to 80% in data centers. Although some companies have pledged to become water-positive—replenishing more freshwater than they consume—by 2030 through a transition to air cooling, only 10% of data center operators track water use across all their facilities.

Earth Day has become the largest civic event in the world

What began in 1970 with 20 million Americans now involves more than 1 billion participants across over 190 countries each year. Earth Day now encompasses rallies, cleanups, and climate actions worldwide.

Switzerland's glaciers have lost ice volume every year since 2001

The trajectory of global warming is projected to cause three-quarters of the country's glaciers to be lost by 2100. Accelerated glacial melting worldwide affects as many as 800 million people who rely on meltwater for agriculture and personal use.

There were more than 20 reported cruise ship outbreaks in 2025

A cruise ship outbreak is officially considered an outbreak when 3% or more of the people aboard a ship report being sick with gastrointestinal illness. It happens often enough that the US Centers for Disease Control and Prevention has a whole program just related to tracking such foodborne illness outbreaks.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Poison ivy will likely become both larger and more resilient due to climate change.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

This real-time tracking of the hantavirus cruise ship outbreak in May 2026 offers a unique glimpse into the global reach of the outbreak and whether the virus sickened passengers and their communities around the world.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

See the 25 of the best photos of auroras from around the world.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

View the ten deadliest tornadoes in US history.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.