Climate change has serious, long-term, and far-reaching negative consequences for our ocean.

Burning fossil fuels, raising livestock, and clearing forests are just three examples of human activities that release billions of tons of CO₂ and other heat-trapping gases into our atmosphere every year, making our planet warmer. The ocean has buffered us from the worst impacts of climate change—absorbing more than 25 percent of the excess CO₂ and more than 90 percent of the excess heat. But these climate services come at a significant cost for marine ecosystems and result in harmful impacts including:

• Increasing ocean temperature: bleaches coral reefs, shifts where fish can live, and decreases ocean wildlife,
• Ocean acidification: causes a depletion of carbonate ions, which are critical for shell-forming animals like oysters, crabs, and shrimp,
• Decreasing oxygen: creates areas that suffocate marine animals, shrinks their habitats, and forces them to swim into places where they are more vulnerable to predators,
• More intense tropical storms and higher sea level: puts coastal communities in harm’s way and destroys coastal wetland habitats which include mangroves and salt marshes.

These and other negative impacts are documented and summarized in the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate—released on September 25, 2019, in Monaco. It is the first IPCC report to focus specifically on the marine realm.

In order to protect the ocean and slow the impacts of climate change, the science indicates we need to take action on two fronts:

• Cut net carbon dioxide emissions to zero by 2050;
• Increase ocean health—by reducing pollution, overfishing and safeguarding critical marine and coastal habitats.

Climate change: A triple threat for the ocean

September 25, 2019 – A just-released scientific report connects a host of ocean changes with human activities that take place largely on land.

MBARI climate change research

MBARI’s technical achievements and knowledge are transforming climate change research with novel methods and technologies. Several MBARI research projects have tackled issues related to climate change, seeking to understand how marine life responds to a changing ocean.

Additional MBARI climate change research:

• 500 new floats to expand global ocean monitoring program
• 30 years of research on the abyssal plain provides clues to climate change
• Lending expertise in the pursuit of clean energy off the California coast
• Measuring the impact of climate change on coral reefs
• Building tools to learn about the many faces of ocean change
• Decades of exploration and discovery yield insights to life in the midwater
• Using an autonomous sailboat to study the exchange of carbon dioxide at the ocean surface

Climate change research from MBARI partners:

• A new study shows the true colors of climate change
• Young white sharks tell the story of a changing Monterey Bay
• Take a trip through time with seaweed
• The changing map of life on Earth

“Environmental conditions throughout the world ocean are changing in response to fossil fuel emissions and greenhouse warming in the atmosphere.”

—Scientist Jim Barry

Climate and the ocean facts

• Fact sheet for the upcoming report from the Intergovernmental Panel on Climate Change

From the Intergovernmental Panel on Climate Change report, The Ocean and Cryosphere in a Changing Climate:

• Carbon dioxide uptake: It is very likely that the ocean has taken up between 20 to 30 percent of total anthropogenic carbon since the 1980s.
• Loss of oxygen: The open ocean is losing oxygen overall with a very likely loss of 0.5 to 3.3 percent between 1970 and 2010 from the surface to depths of 1,000 meters. The oxygen minimum zones are likely expanding by 3 to 8 percent, most notably in tropical areas.
• Heat: The ocean has taken up more than 90 percent of the excess heat in the climate system since 1970. The rate of ocean warming has more than doubled since 1993.
• Coastal wetlands: Nearly 50 percent of coastal wetlands have been lost over the 20th century since pre-industrial time, as a result of the combined effect of localized human pressures, sea level rise, warming and extreme climactic events.
• Fisheries: In many regions, declines in the abundance of fish and shellfish stocks due to direct and indirect effects of global warming have already reduced fisheries catches.
• Harmful algal blooms: Harmful algal blooms show range expansion and increased frequency in coastal areas since the 1980s in response to both climatic and non-climatic drivers. The observed trends are attributed partly to the effects of ocean warming, acidification, and loss oxygen as well as eutrophication and pollution.

Climate change in Monterey Bay

• Temperature: The surface of Monterey Bay has warmed about 0.8°C (1.4°F) since 1930.
• Acidity: 10 percent increase in acidity near the surface over the last 20 years.
• Oxygen: The minimum oxygen zone is getting bigger.

MBARI Publications

• Time-of-detection as a metric for prioritizing between climate observation quality, frequency, and duration
• Metrics for the evaluation of the Southern Ocean in coupled climate models and Earth system models
• Harnessing marine microclimates for climate change adaptation and marine conservation
• Climate variability and change: Response of a coastal ocean ecosystem
• Combined climate- and prey-mediated range expansion of Humboldt squid (Dosidicus gigas), a large marine predator in the California Current System
• Oceanographic and biological effects of shoaling of the oxygen minimum zone
• Extreme plasticity in life-history strategy allows a migratory predator (jumbo squid) to cope with a changing climate
• Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean
• Climate change impacts on marine ecosystems
• Conservation of deep pelagic biodiversity
• Invasive range expansion by the Humboldt squid, Dosidicus gigas, in the eastern North Pacific
• Climate-related long-term faunal changes in a California rocky intertidal community

Lesson plans

The following lesson plans about the ocean and climate change were created by teachers participating in the EARTH teacher workshops. EARTH—which stands for Education and Research: Testing Hypotheses—uses near-real-time data from ocean observatories to create lessons for students.

• Climate change impacts on animal populations
• Pacific Islands climate change resources
• What’s the bigger picture?

Resources

Climate change:

• Intergovernmental Panel on Climate Change
• U.S. Environmental Protection Agency Climate Change Indicators
• Climate Central
• Climate Interpreter
• State of California Ocean Acidification Action Plan
• California Climate Change Assessment
• Southern Ocean Carbon and Climate Observations and Modeling Project

Specific subjects:

• Ocean temp and hurricanes, Climate Central
• Ocean Heat Waves Are Threatening Marine Life, The New York Times
• The Ocean Is Losing Its Breath. Here’s the Global Scope. Smithsonian Environmental Research Center

Science publications:

• Recent pace of change in human impact on the world’s ocean
• Global ensemble projections reveal trophic amplification of ocean biomass declines with climate change
• An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions
• The oceanic sink for anthropogenic CO₂ from 1994 to 2007
• The Impact of Climate Change on California’s Marine Ecosystems: Beyond Sea Level Rise