Surprise! Unexpected ocean heat waves are becoming the norm
Credit: Viv Lynch/flickr

Surprise! Unexpected ocean heat waves are becoming the norm

Ocean heat waves, which can push out fish, plankton and other aquatic life, are happening far more frequently than previously thought, according to a study published today in the Proceedings of the National Academy of Sciences.


"Based on historical and lived experience, people expect certain conditions to prevail in the ecosystems they depend upon. Climate change is now introducing strong trends that push conditions beyond historic levels," the authors wrote.

Led by the Gulf of Maine Research Institute, researchers looked at 65 large marine ecosystems around the world over the past 164 years to determine how frequently "surprising" ocean temperatures occur, with surprising defined as an event expected to occur about two times in 100 years, lead author and chief scientific officer at the Gulf of Maine Research Institute Andrew Pershing told EHN via email.

Pershing and colleagues reported that over the past seven years, the planet averaged 12 ecosystems each year experiencing the kind of unusually warm temperatures that someone in the given region would expect to see only a couple times in a century. In 2016 alone there were 23 such events.

"Across the 65 ecosystems we examined, we expected about six or seven of them would experience these 'surprises' each year," Pershing said in a statement.

The results are in line with what scientists continue to warn: oceans are the Earth's largest heat collector. According to the National Oceanic and Atmospheric Administration, more than 90 percent of Earth's warming over the past 50 years has happened in the ocean.

These increasing surprises documented by Pershing and other researchers are happening all over the world—the Arctic, North Atlantic, eastern Pacific, and near Australia—and spell trouble for corals, fish and tiny organisms at the base of the food chain.

While overall warming, not the surprise warming events, has a more profound effect on marine species, the researchers did find, via modeling, that surprise heat waves will decrease biodiversity. They pointed to warming trends in the Tropics as an example, where there is increasingly less coral reef cover and complexity.

Humans need to adapt and plan for these marine heat waves as well, the authors write. "To be successful, human institutions including businesses, communities, management agencies, and governments will need to adopt strategies that look forward rather than backward," they wrote.

As an example of "backward thinking," they pointed to the rapid increase in temperature in the Gulf of Maine and the resulting population collapse in the economic and ecologically vital cod fishery.

"We are entering a world where history is an unreliable guide for decision-making," Pershing said. "In a rapidly changing world, betting that trends will continue is a much better strategy."

See the full study here.

"We are entering a world where history is an unreliable guide for decision-making"

Urban heat officers face rising temperatures - and expectations

The “insidious” impact of extreme heat is challenging cities to find cross-disciplinary solutions.
Sunrise in the woods

Get our Good News newsletter

Get the best positive, solutions-oriented stories we've seen on the intersection of our health and environment, FREE every Tuesday in your inbox. Subscribe here today. Keep the change tomorrow.

As Himalayan glaciers melt, a water crisis looms in South Asia

Warmer air is thinning most of the vast mountain range’s glaciers, known as the Third Pole because they contain so much ice. The melting could have far-reaching consequences for flood risk and for water security for a billion people who rely on meltwater for their survival.

Live near water? Get flood insurance, FEMA admin says after Ian

“Just because you’re not required to buy flood insurance doesn’t mean you don’t have the option to buy it.”

Bitcoin climate impact greater than gold mining, study shows

Environmental damage of producing cryptocurrency averages 35% of its market value over past five years.

This campus takes “learning environment” literally

At the University of the District of Columbia, sustainable infrastructure is part of the educational experience.

In a first, U.S. appoints a diplomat for plants and animals

For the first time, the United States is designating a special diplomat to advocate for global biodiversity amid what policymakers here and overseas increasingly recognize as an extinction crisis.

From our Newsroom
Chemical recycling grows  along with concerns of its impacts

Chemical recycling grows — along with concerns about its environmental impacts

Industry says chemical recycling could solve the plastic waste crisis, but environmental advocates and some lawmakers are skeptical.

Failure of the universities: The culture gap is now near lethal

Universities are failing us

Our educational systems are failing to prepare people for existential environmental threats

Shell's new petrochemical complex in southwestern Pennsylvania

The Titans of Plastic

Pennsylvania becomes the newest sacrifice zone for America’s plastic addiction.

Ruth Greenspan Bell: Wealth and the climate dilemma

Ruth Greenspan Bell: Wealth and the climate dilemma

Developing countries that increase their fossil fuel production are at a crossroads: securing their own long-term well-being or earning revenue to finance programs to support immediate economic growth.

Solving the climate crisis will help both ‘sacrifice zones’ and ‘cute’ puffins

Solving the climate crisis will help both ‘sacrifice zones’ and ‘cute’ puffins

Curbing pollution for families in Chicago calms the climatic conditions that drive fish away from puffins half a continent away.

puffin tern recovery climate change

Good news: A good year for puffins and terns, despite climate change

A visit to a remote Maine island finds puffins and terns rebounding despite climate change

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.