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Biotic calcification impacts on marine carbon dioxide removal additionality

Pteropod shell

Why we care
There are several challenges that can limit the efficiency and effectiveness of marine carbon dioxide removal methods. One potential consequence of some methods is increased growth of organisms that build shells out of calcium carbonate, or calcification (shell building). Calcification releases carbon dioxide into seawater, which may reduce the efficiency of carbon removal projects. This project will explore the potential impacts of increased calcification using ocean model simulations. 

What we will do
“We need to make sure various ocean alkalinity enhancement techniques not only take up the carbon we expect in the short term, but also hold on to that carbon for hundreds of years” says Dr. Kelly Kearny of the University of Washington CIOCES. “Our project will calculate how big an effect impacts to calcification could potentially have on long-term carbon uptake.” The team will use simulations from two different model frameworks to identify a range of efficiency reductions that could come from calcification. Simulations will be based on proposed real-world applications of marine carbon removal. Accurate estimation of efficiency and the uncertainty of efficiency will be important to determine the value of carbon removal credits in market settings. In addition to testing this important feedback, researchers will also explore natural processes that mimic this calcification feedback with existing ocean carbon data. 

Benefit of our work 
This project may inform carbon markets and carbon prices/discounts for ocean carbon dioxide removal projects. These results could provide an important way of setting the price – or discount rate. Models like the one produced here are important because the long time scales and large spatial scales involved in this process make it very difficult to measure in a laboratory or at sea.

Award amount: $1,250,482
Funding source(s): NOAA
IRA funding? Yes
Project duration: 4 years

Kelly Kearney, University of Washington (CICOES)
Brendan Carter, University of Washington
Kristen Krumhardt, National Center For Atmospheric Research
Darren Pilcher, University of Washington

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The NOAA Ocean Acidification Program (OAP) works to prepare society to adapt to the consequences of ocean acidification and conserve marine ecosystems as acidification occurs. Learn more about the human connections and adaptation strategies from these efforts.

Adaptation approaches fostered by the OAP include:


Using models and research to understand the sensitivity of organisms and ecosystems to ocean acidification to make predictions about the future, allowing communities and industries to prepare


Using these models and predictions as tools to facilitate management strategies that will protect marine resources and communities from future changes


Developing innovative tools to help monitor ocean acidification and mitigate changing ocean chemistry locally


On the Road

Drive fuel-efficient vehicles or choose public transportation. Choose your bike or walk! Don't sit idle for more than 30 seconds. Keep your tires properly inflated.

With your Food Choices

Eat local- this helps cut down on production and transport! Reduce your meat and dairy. Compost to avoid food waste ending up in the landfill

With your Food Choices

Make energy-efficient choices for your appliances and lighting. Heat and cool efficiently! Change your air filters and program your thermostat, seal and insulate your home, and support clean energy sources

By Reducing Coastal Acidification

Reduce your use of fertilizers, Improve sewage treatment and run off, and Protect and restore coastal habitats

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You've taken the first step to learn more about ocean acidification - why not spread this knowledge to your community?

Every community has their unique culture, economy and ecology and what’s at stake from ocean acidification may be different depending on where you live.  As a community member, you can take a larger role in educating the public about ocean acidification. Creating awareness is the first step to taking action.  As communities gain traction, neighboring regions that share marine resources can build larger coalitions to address ocean acidification.  Here are some ideas to get started:

  1. Work with informal educators, such as aquarium outreach programs and local non-profits, to teach the public about ocean acidification. Visit our Education & Outreach page to find the newest tools!
  2. Participate in habitat restoration efforts to restore habitats that help mitigate the effects of coastal acidification
  3. Facilitate conversations with local businesses that might be affected by ocean acidification, building a plan for the future.
  4. Partner with local community efforts to mitigate the driver behind ocean acidification  – excess CO2 – such as community supported agriculture, bike & car shares and other public transportation options.
  5. Contact your regional Coastal Acidification Network (CAN) to learn how OA is affecting your region and more ideas about how you can get involved in your community
       More for Taking Community Action