Ocean warming

The world’s coral reefs are like underwater cities, bustling with all kinds of fish and sea animals. Coral reefs cover less than 1% of the ocean, but they support an estimated 25% of all marine species, including many important fish species. The economic value of the services that these complex ecosystems provide is estimated at over US$3.4 billion yearly just in the U.S. Today, rising ocean temperatures threaten many reefs’ survival. When ocean waters become too warm for too long, corals expel the colorful symbiotic algae, called zooxanthellae, that live in their tissues – a process called coral bleaching. These algae provide the corals with food, so bleached corals are vulnerable to starvation and disease and may die if the water does not cool quickly enough. With global ocean heat at record levels, scientists have confirmed that a global coral bleaching event is underway. Since the beginning of 2023, corals have been dying in the Indian, Pacific and Atlantic...

Preparing for Atlantic hurricane season is always a priority in the Caribbean, especially when forecasts project high numbers of storms, as they do for 2024. The region’s most devastating storm in recent years, Hurricane Maria, struck in September 2017 and inflicted unprecedented destruction on Puerto Rico, Dominica, St. Croix and other islands. Maria killed more than 3,000 people and caused about US$96 billion in damage. It devastated Puerto Rico’s electric power system, leaving 1.5 million customers in the dark for up to 328 days – the longest blackout in U.S. history. These outages had cascading impacts on other infrastructure, such as water and communications systems. Today, the Caribbean region is experiencing new climate-related challenges. Prolonged extreme heat and humid days are increasing because of the accelerated warming of ocean waters. In response to these increasingly frequent and extreme weather events, I teamed up with a dozen other resea...

Coral reefs are some of the oldest, most diverse ecosystems on Earth, and among the most valuable. They nurture 25% of all ocean life, protect coasts from storms and add billions of dollars yearly to the global economy through their influences on fisheries, new pharmaceuticals, tourism and recreation. Today, the world’s coral reefs are degrading at unprecedented rates due to pollution, overfishing and destructive forestry and mining practices on land. Climate change driven by human activities is warming and acidifying the ocean, triggering what could be the largest coral bleaching event on record. Under these combined pressures, scientists project that most corals could go extinct within a few generations. I am a marine biologist at the Smithsonian’s National Zoo and Conservation Biology Institute. For 17 years, I have worked with colleagues to create a global science program called the Reef Recovery Initiative that aims to help save coral reefs by using the scienc...

As oceans waves rise and fall, they apply forces to the sea floor below and generate seismic waves. These seismic waves are so powerful and widespread that they show up as a steady thrum on seismographs, the same instruments used to monitor and study earthquakes. That wave signal has been getting more intense in recent decades, reflecting increasingly stormy seas and higher ocean swell. In a new study in the journal Nature Communications, colleagues and I tracked that increase around the world over the past four decades. These global data, along with other ocean, satellite and regional seismic studies, show a decadeslong increase in wave energy that coincides with increasing storminess attributed to rising global temperatures. What seismology has to do with ocean waves Global seismographic networks are best known for monitoring and studying earthquakes and for allowing scientists to create images of the planet’s deep interior. These highly sensitive instruments continu...