{"id":20,"date":"2017-07-27T16:43:21","date_gmt":"2017-07-27T20:43:21","guid":{"rendered":"http:\/\/web.whoi.edu\/ocb-fert\/?page_id=20"},"modified":"2017-12-20T17:44:50","modified_gmt":"2017-12-20T21:44:50","slug":"science-background","status":"publish","type":"page","link":"https:\/\/web.whoi.edu\/ocb-fert\/science-background\/","title":{"rendered":"Science Background"},"content":{"rendered":"

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The Basics<\/h2>\n

Increases in atmospheric carbon dioxide (CO2<\/sub>) levels and associated changes in the earth’s climate that have occurred since the preindustrial era have prompted scientists and engineers to devise strategies for removing some of this excess CO2<\/sub>\u00a0from the atmosphere. One such strategy, called\u00a0ocean fertilization<\/strong>, involves the amplification of a natural system in the ocean called the\u00a0biological pump<\/a>.<\/p>\n

Ocean fertilization is a form of geoengineering (large-scale human actions to\u00a0deliberately manipulate environmental systems) that involves adding nutrients to the upper (sunlit) layers of the ocean to stimulate phytoplankton activity (photosynthesis) in an attempt to draw down atmospheric CO2<\/sub>\u00a0levels. Phytoplankton are tiny marine plants that form the base of the marine food web and are naturally limited by the availability of elements such as nitrogen and iron. Proposed ocean fertilization strategies have included the direct application of micronutrients (e.g., iron) and macronutrients (e.g., nitrogen) to the ocean surface, as well as technologies like wave pumping and floating tubes to physically move deeper, more nutrient-rich waters to the surface.<\/p>\n

What is Macronutrient Fertilization?<\/h3>\n
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This artist’s rendition of an Ocean Nourishment Corporation plant shows how the company would pump urea into the ocean to stimulate plankton growth.\u00a0Image:\u00a0Courtesy of Ocean Nourishment Corporation<\/p><\/div>\n

Macronutrient fertilization refers to the addition of growth-limiting macronutrients such as nitrogen and phosphorus to the surface ocean to stimulate phytoplankton production, which is expected to increase photosynthesis and remove CO2<\/sub>\u00a0from the atmosphere.<\/p>\n

Large-scale ocean nourishment with urea, a nitrogen-rich organic compound commonly used in fertilizers, has been proposed as a potential ocean fertilization strategy by the\u00a0Ocean Nourishment Corporation (ONC)<\/a>, an Australia-based company.<\/p>\n

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What is Micronutrient Fertilization?<\/h3>\n
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Map of iron fertilization sites (Courtesy of Woods Hole Oceanographic Institution).<\/p><\/div>\n

Micronutrient fertilization refers to the addition of growth-limiting micronutrients such as iron to the surface ocean to stimulate phytoplankton production, which is expected to increase photosynthesis and remove CO2<\/sub>\u00a0from the atmosphere.<\/p>\n

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International Iron Fertilization Experiments<\/h3>\n