{"id":2979995,"date":"2026-08-13T13:02:34","date_gmt":"2026-08-13T20:02:34","guid":{"rendered":"https:\/\/www.esri.com\/arcgis-blog\/?post_type=blog&p=2979995"},"modified":"2026-08-13T13:02:34","modified_gmt":"2026-08-13T20:02:34","slug":"where-should-we-explore-marine-carbon-dioxide-removal","status":"publish","type":"blog","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/experience-builder\/decision-support\/where-should-we-explore-marine-carbon-dioxide-removal","title":{"rendered":"Where Should We Explore Marine Carbon Dioxide Removal?"},"author":346272,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_searchwp_excluded":""},"categories":[37141],"tags":[30111,22821,23391],"industry":[],"product":[400032],"class_list":["post-2979995","blog","type-blog","status-publish","format-standard","hentry","category-decision-support","tag-data-visualization","tag-oceans-and-maritime","tag-spatial-analytics","product-experience-builder"],"acf":{"authors":[{"ID":346272,"user_firstname":"Carl","user_lastname":"Spangrude","nickname":"Carl Spangrude","user_nicename":"cspangrude","display_name":"Carl Spangrude","user_email":"cspangrude@esri.com","user_url":"","user_registered":"2023-09-21 22:57:05","user_description":"Carl joined Esri Professional Services in 2022 to support implementing solutions to the climate crisis. His prior experience includes scientific ballooning and atmospheric science research with Montana Space Grant Consortium. At Esri, he writes proposals, manages projects, and serves as an Advisor for the Esri Advantage Program. In these roles, Carl applies his interests and expertise in GIS, natural resource conservation, and atmospheric science to understand customers' needs and guide them towards success using the suite of ArcGIS products.","user_avatar":""},{"ID":6701,"user_firstname":"Keith","user_lastname":"VanGraafeiland","nickname":"Keith VanGraafeiland","user_nicename":"kvangraafeiland","display_name":"Keith VanGraafeiland","user_email":"KVanGraafeiland@esri.com","user_url":"https:\/\/oceans-esrioceans.hub.arcgis.com\/","user_registered":"2018-03-02 00:18:44","user_description":"Keith VanGraafeiland is a Senior Principal GIS Engineer at Esri and Ocean Content Lead for the ArcGIS Living Atlas of the World. With over 20 years of experience, Keith specializes in marine and environmental GIS, remote sensing, and advanced data science. Keith\u2019s work bridges oceanography and data science, using machine learning and analytics to turn complex data into actionable insights for the GIS community.","user_avatar":""}],"short_description":"Using spatial data, ocean science, and human-use considerations to help determine site suitability for ocean iron fertilization research.","flexible_content":[{"acf_fc_layout":"content","content":"

When Climate Solutions Meet Place<\/span><\/span>\u00a0<\/span><\/h2>\n

Climate change\u00a0<\/span>is driving an urgent search for\u00a0<\/span>new solutions<\/span>\u00a0that can complement\u00a0<\/span>emissions<\/span>\u00a0reductions and help address the global scale of this challenge. Among the approaches receiving growing attention is marine carbon d<\/span>ioxi<\/span>de removal<\/span>\u00a0(<\/span>mCDR<\/span>)<\/span>:<\/span>\u00a0<\/span>a diverse<\/span>\u00a0set of strategies designed to enhance the ocean\u2019s ability to absorb and store carbon.<\/span>\u00a0<\/span>While\u00a0<\/span>mCDR<\/span>\u00a0is not a substitute\u00a0<\/span>for reducing greenhouse gas emissions,\u00a0<\/span>there is\u00a0<\/span>wide\u00a0<\/span>consensus\u00a0<\/span>amongst<\/span>\u00a0international resear<\/span>che<\/span>r<\/span>s<\/span>\u00a0<\/span>(<\/span><\/span>IPCC<\/span><\/span><\/a>)<\/span>\u00a0<\/span>that carbon dioxide removal will also be needed to complement <\/span>emissions\u00a0<\/span>reductions and to eventually reverse the ongoing climate disruption being caused by the existing buildup of greenhouse gases.<\/span><\/span><\/p>\n

As interest in\u00a0<\/span>mCDR<\/span>\u00a0grows, so does the need for tools that can help guide where research,\u00a0<\/span>testing, and\u00a0<\/span>potential deployments should occur.\u00a0<\/span>C<\/span>limate solution conversations\u00a0<\/span>often focus on\u00a0<\/span><\/span>wh<\/span>ich<\/span><\/span>\u00a0approaches we should\u00a0<\/span>pursue<\/span>.<\/span>\u00a0<\/span>Yet<\/span>\u00a0<\/span>scientists and practitioners are increasingly\u00a0<\/span>recognizing\u00a0<\/span>that\u00a0<\/span><\/span>where<\/span><\/span>\u00a0we\u00a0<\/span>pursue\u00a0<\/span>solutions can be just as important<\/span>, and<\/span>\u00a0<\/span>mCDR<\/span>\u00a0is one such area where geography matters deeply. The ocean is vast, dynamic, and interconnected with ecosystems, economies, and communities.<\/span><\/span>\u00a0<\/span><\/span><\/span>Not every\u00a0<\/span>location\u00a0<\/span>is\u00a0<\/span>equally suitable, and some areas may be in<\/span>appropriate<\/span>\u00a0<\/span>or\u00a0<\/span>ir<\/span>responsible<\/span>\u00a0<\/span>for testing or deploying\u00a0<\/span>mCDR<\/span>\u00a0approaches.<\/span><\/span>\u00a0<\/span><\/p>\n"},{"acf_fc_layout":"image","image":{"ID":2979996,"id":2979996,"title":"","filename":"adobestock-294100042-scaled.jpg","filesize":1111334,"url":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-scaled.jpg","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/experience-builder\/decision-support\/where-should-we-explore-marine-carbon-dioxide-removal\/texture-of-marine-splashes-crashing-ocean-wave-foam-structure","alt":"","author":"346272","description":"","caption":"","name":"texture-of-marine-splashes-crashing-ocean-wave-foam-structure","status":"inherit","uploaded_to":2979995,"date":"2026-08-12 19:15:26","modified":"2026-08-12 19:16:09","menu_order":0,"mime_type":"image\/jpeg","type":"image","subtype":"jpeg","icon":"https:\/\/www.esri.com\/arcgis-blog\/wp-includes\/images\/media\/default.png","width":2560,"height":1440,"sizes":{"thumbnail":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-213x200.jpg","thumbnail-width":213,"thumbnail-height":200,"medium":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-scaled.jpg","medium-width":464,"medium-height":261,"medium_large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-scaled.jpg","medium_large-width":768,"medium_large-height":432,"large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-scaled.jpg","large-width":1920,"large-height":1080,"1536x1536":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-1536x864.jpg","1536x1536-width":1536,"1536x1536-height":864,"2048x2048":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-2048x1152.jpg","2048x2048-width":2048,"2048x2048-height":1152,"card_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-826x465.jpg","card_image-width":826,"card_image-height":465,"wide_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/adobestock-294100042-1920x1080.jpg","wide_image-width":1920,"wide_image-height":1080}},"image_position":"center","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"

This is where spatial thinking comes in. By combining ocean science with geographic information systems (GIS), we can begin to ask better questions about suitability: Which parts of the ocean are biophysically promising? Which areas should be avoided due to ecological sensitivity or human use? And how can we make these tradeoffs transparent to scientists, policymakers, and the public?<\/span>\u00a0<\/span><\/p>\n

This article tells the story of how\u00a0ArcGIS-based weighted raster overlay suitability modeling\u00a0is being applied to\u00a0mCDR, through a collaboration with\u00a0<\/span>Ocean Visions<\/span><\/b><\/a>,\u00a0helping stakeholders\u00a0identify\u00a0and evaluate potential\u00a0opportunities\u00a0in\u00a0a data-driven, interpretable, and science-informed way.<\/span>\u00a0<\/span><\/p>\n

 <\/p>\n

A Primer on Marine Carbon Dioxide Removal (<\/span>mCDR<\/span>)<\/span><\/span>\u00a0<\/span><\/h2>\n

One\u00a0<\/span>such\u00a0<\/span>approach\u00a0<\/span>is\u00a0<\/span>ocean iron fertilization<\/span>, a method that involves adding\u00a0<\/span>small amounts<\/span>\u00a0of iron to iron-limited regions of the ocean to stimulate phytoplankton growth. Phytoplankton\u00a0<\/span>absorb<\/span>\u00a0carbon dioxide through photosynthesis, and a\u00a0<\/span>portion<\/span>\u00a0of that carbon can be transported to the deep ocean when organisms die or are consumed.<\/span><\/p>\n"},{"acf_fc_layout":"image","image":{"ID":2979997,"id":2979997,"title":"","filename":"Microalgae.png","filesize":701094,"url":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae.png","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/experience-builder\/decision-support\/where-should-we-explore-marine-carbon-dioxide-removal\/microalgae","alt":"Diagram showing the marine microalgae cultivation process","author":"346272","description":"","caption":"Ocean nutrient fertilization process diagram (Image source: https:\/\/oceanvisions.org\/mcdr-illustrations\/).","name":"microalgae","status":"inherit","uploaded_to":2979995,"date":"2026-08-12 19:18:46","modified":"2026-08-12 19:20:14","menu_order":0,"mime_type":"image\/png","type":"image","subtype":"png","icon":"https:\/\/www.esri.com\/arcgis-blog\/wp-includes\/images\/media\/default.png","width":2560,"height":1399,"sizes":{"thumbnail":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae-213x200.png","thumbnail-width":213,"thumbnail-height":200,"medium":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae.png","medium-width":464,"medium-height":254,"medium_large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae.png","medium_large-width":768,"medium_large-height":420,"large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae.png","large-width":1920,"large-height":1049,"1536x1536":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae-1536x839.png","1536x1536-width":1536,"1536x1536-height":839,"2048x2048":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae-2048x1119.png","2048x2048-width":2048,"2048x2048-height":1119,"card_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae-826x451.png","card_image-width":826,"card_image-height":451,"wide_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/Microalgae-1920x1049.png","wide_image-width":1920,"wide_image-height":1049}},"image_position":"center","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"

In theory, this can contribute to long-term carbon storage\u2014but only under the right conditions\u00a0and with\u00a0careful consideration of risks and uncertainties.<\/span>\u00a0<\/span><\/p>\n

Because\u00a0mCDR\u00a0approaches interact with complex ocean systems, responsible research requires tools that can integrate many types of data at once: physical oceanography, biogeochemistry, ecological constraints, policy and regulations, and human activity.<\/span>\u00a0<\/span><\/p>\n

 <\/p>\n

What Is Suitability Mapping, and Why Use It?<\/span><\/span>\u00a0<\/span><\/h2>\n

Suitability mapping is a spatial analysis technique used to identify where conditions are more (or less) appropriate for a given purpose. It is commonly used in fields like conservation planning, renewable energy siting, and natural resource management. At its core, suitability modeling brings together multiple datasets, standardizes them to a common scale, and combines them using transparent rules.<\/span>\u00a0<\/span><\/p>\n

In ArcGIS, one powerful way to do this is through\u00a0<\/span>weighted raster overlay modeling<\/span><\/b><\/a>. Each dataset is represented as a raster (a grid of pixels), where every pixel has a value. Those values are reclassified into suitability scores (for example, low to high), and each dataset is\u00a0assigned\u00a0a relative weight based on its importance. The result is a composite map that shows relative suitability across space.<\/span>\u00a0<\/span><\/p>\n"},{"acf_fc_layout":"image","image":{"ID":2979998,"id":2979998,"title":"","filename":"WRO_process-scaled.png","filesize":376630,"url":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-scaled.png","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/experience-builder\/decision-support\/where-should-we-explore-marine-carbon-dioxide-removal\/wro_process","alt":"Graphic examples of different suitability model layers contributing to overall model influence through unique percentage weights, and each layers' pixels receiving suitability scores which are combined to produce the final model output of suitability.","author":"346272","description":"","caption":"Left: each input layer is assigned a weight corresponding to that layer\u2019s influence on the final output. Right: each pixel value is multiplied by that layer\u2019s percentage weight and the results are summed to create output raster values. In the upper left pixel, the values for the two inputs become (2 * 0.75) = 1.5 and (3 * 0.25) = 0.75. The sum of 1.5 and 0.75 is 2.25, and the final output value is rounded to 2. ","name":"wro_process","status":"inherit","uploaded_to":2979995,"date":"2026-08-12 19:22:12","modified":"2026-08-12 19:25:11","menu_order":0,"mime_type":"image\/png","type":"image","subtype":"png","icon":"https:\/\/www.esri.com\/arcgis-blog\/wp-includes\/images\/media\/default.png","width":2560,"height":1036,"sizes":{"thumbnail":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-213x200.png","thumbnail-width":213,"thumbnail-height":200,"medium":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-scaled.png","medium-width":464,"medium-height":188,"medium_large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-scaled.png","medium_large-width":768,"medium_large-height":311,"large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-scaled.png","large-width":1920,"large-height":777,"1536x1536":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-1536x622.png","1536x1536-width":1536,"1536x1536-height":622,"2048x2048":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-2048x829.png","2048x2048-width":2048,"2048x2048-height":829,"card_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-826x334.png","card_image-width":826,"card_image-height":334,"wide_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_process-1920x777.png","wide_image-width":1920,"wide_image-height":777}},"image_position":"center","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"image","image":{"ID":2980000,"id":2980000,"title":"","filename":"WRO_maps_2-scaled.png","filesize":1426174,"url":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-scaled.png","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/experience-builder\/decision-support\/where-should-we-explore-marine-carbon-dioxide-removal\/wro_maps_2","alt":"Three maps showing global ocean suitability scores based on distance to ports (km), sea surface temperature (C) and a combined suitability output of those two input layers modeled together.","author":"346272","description":"","caption":"The Distance to Ports and Sea Surface Temperature input layers are combined using the above weighted raster overlay process to produce a composite map of combined suitability scores based on these two layers. ","name":"wro_maps_2","status":"inherit","uploaded_to":2979995,"date":"2026-08-12 19:25:53","modified":"2026-08-12 19:51:46","menu_order":0,"mime_type":"image\/png","type":"image","subtype":"png","icon":"https:\/\/www.esri.com\/arcgis-blog\/wp-includes\/images\/media\/default.png","width":2560,"height":1486,"sizes":{"thumbnail":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-213x200.png","thumbnail-width":213,"thumbnail-height":200,"medium":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-scaled.png","medium-width":450,"medium-height":261,"medium_large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-scaled.png","medium_large-width":768,"medium_large-height":446,"large":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-scaled.png","large-width":1861,"large-height":1080,"1536x1536":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-1536x891.png","1536x1536-width":1536,"1536x1536-height":891,"2048x2048":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-2048x1188.png","2048x2048-width":2048,"2048x2048-height":1188,"card_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-801x465.png","card_image-width":801,"card_image-height":465,"wide_image":"https:\/\/www.esri.com\/arcgis-blog\/app\/uploads\/2026\/08\/WRO_maps_2-1861x1080.png","wide_image-width":1861,"wide_image-height":1080}},"image_position":"center","orientation":"horizontal","hyperlink":""},{"acf_fc_layout":"content","content":"

This approach is particularly well suited to ocean science, where most global datasets\u2014such as temperature, nutrients, or bathymetry\u2014are already raster-based. It also makes assumptions explicit, which is critical for scientific credibility and stakeholder trust.<\/span><\/span>\u00a0<\/span><\/p>\n

 <\/p>\n

The Ocean Visions <\/span>mCDR<\/span>\u00a0<\/span>Site\u00a0<\/span>Suitability\u00a0<\/span>Planning Tool<\/span><\/span>\u00a0<\/span><\/h2>\n

Through a guided interface, users can:<\/span>\u00a0<\/span><\/p>\n

Ocean Visions partnered with Esri to translate this analytical approach into an accessible, web-based tool: the\u00a0<\/span>Ocean Iron Fertilization Site Suitability\u00a0Planning Tool<\/span><\/b><\/a>.\u00a0Rather than producing a single static map, this\u00a0tool allows users to explore how different assumptions affect outcomes.<\/span>\u00a0<\/span><\/p>\n

Marine carbon dioxide removal refers to a\u00a0<\/span><\/span>family of approaches<\/span><\/span><\/a>\u00a0<\/span>that\u00a0<\/span>aim<\/span>\u00a0to enhance the ocean\u2019s natural ability to absorb and store carbon from the atmosphere.\u00a0<\/span>These approaches\u00a0<\/span>leverage<\/span> either biological or chemical processes in the ocean to accelerate carbon uptake and storage.<\/span><\/span><\/p>\n