Why are MPAs, biodiversity and climate change important and how are they connected?

The ocean covers over two-thirds of the Earth’s surface and is critical in regulating the global climate. It is home to a vast array of species and habitats, many of them still unknown. Ocean biodiversity and a healthy ocean are interlinked, together they promote ecosystem resilience. Everyone relies on healthy marine ecosystems to support life on this planet.

The ocean helps reduce the impacts of climate change, capturing nearly a third of the anthropogenic carbon dioxide emitted into the atmosphere1,2,3, and absorbing 90% of the excess heat trapped by those emissions4,5. The carbon captured and stored in the ocean’s ecosystems is often referred to as blue carbon.

However, the ocean is being impacted by capturing and absorbing our excess carbon dioxide and heat. The impacts include increased water temperatures, ocean acidification, deoxygenation and sea level rise6,7,8, triggering severe changes in global marine ecosystems.

Marine Protected Areas (or MPAs) are areas which have been designated to protect marine habitats and species. If created, monitored, and managed correctly, MPAs or networks of MPAs can protect marine ecosystems, enhance biodiversity, and can provide a nature-based solution to help mitigate, adapt, and build resilience to the effects of climate change.

MPA networks can protect blue carbon habitats, which can include a wide range of habitats including sediments, mangroves, salt marshes, seagrass beds, and kelp forests. MPAs can prevent loss and degradation of those habitats, and their associated blue carbon reserves9. They may also enable new carbon sequestration through the restoration of degraded marine habitats10 or carbon storage within sediments. By conserving or enhancing marine biodiversity, MPA networks can increase the resilience of marine habitats and ecosystems to adapt to the impacts of climate change. Additionally, there is the potential for the increased biodiversity and biomass of certain species within the MPA network to spill-over into other areas, potentially supporting the resilience of surrounding ecosystems.

Effectively managed MPAs are one of the most cost-effective strategies the world has to protect the ocean’s biodiversity11. However, there are many evidence gaps in the global understanding of how to maximize the benefits of MPAs as nature-based solutions.

Urgent action is required to produce the evidence needed to inform decisions-makers, safeguarding the ocean and the services it provides to nature and people12.

Climate change is a global challenge which requires global responses. As the evidence gaps are filled by the global community, there is much we can do to learn from each other, working collaboratively to share evidence, knowledge, and solutions.


  1. Greg H. Rau. (2014). Enhancing the ocean's role in CO2 mitigation in Global Environmental Change, in Handbook of Global Environmental Pollution, Vol. 1, ed. B. Freedman, pp: 817.
  2. Le Quere, C., Andrew, RM, Friedlingstein, P., Sitch, S., Pongratz, J., Manning, AC, et al. (2018). Global carbon budget 2017. The Journal of Earth System Science. Data 10 pp: 405.
  3. Nicolas Gruber, D. Clement, B. Carter, R. van Heuven S. Feely, M. Hoppema, M. Ishii Key R., et al. (2019). The oceanic sink for anthropogenic CO2 from 1994 to 2007. Science. Vol 363, pp. 1193
  4. Resplandy, L, RF Keeling, Eddebbar And, Brooks MK, Wang R, L Bopp, Long MC, JP Dunne, Koeve W, Oschlies A. (2018). Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition. Nature, Vol 563, pp. 105.
  5. Laure Zanna, Samar Khatiwala, Jonathan M. Gregory, Jonathan Ison, Patrick Heimbach (2019). Global reconstruction of historical ocean heat storage and transport. Proceedings of the National Academy of Sciences of the United States of America, Vol 116 (4), pp. 1126.
  6. Ove Hoegh-Guldberg & John F. Bruno. (2010). The Impact of Climate Change on the World's Marine Ecosystem. Science, Vol.328, pp: 1523
  7. Hans-O. Pörtner, Karl D., P. Boyd, W. Cheung, Lluch-Cota S., Zavialov P., et al. (2014). "Ocean Systems", in Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A. Global and Sectoral Aspects. Contribution of Working Groups II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, eds. Field CB, VR Barros, DJ Dokken, KL Mach, MD Mastrandrea, Bilir TF et al. (New York, NY: Cambridge University Press), 411-484.
  8. Jean-Pierre Gattuso, Alexandre Magnan K., Laurent Bopp, William Cheung WL, Carlos M. Duarte, Jochen Hinkel, Mcleod Elizabeth, Fiorenza Micheli, Oschlies Andreas, Phillip Williamson, Billé Raphael, Chalastani Vasiliki I., D. Ruth Gates, Irisson Jean-Olivier, Middelburg Jack J., Pörtner Hans-Otto, Rau Greg H. (2018). Ocean Solutions to Address Climate Change and Its Effects on Marine Ecosystems. Frontiers in Marine Science, Vol 5, pp. 337.
  9. International Union for Conservation of Nature. Issues Brief. Marine Protected Areas and Climate Change. November 2017
  10. International Union for Conservation of Nature. Issues Brief. Marine Protected Areas and Climate Change. November 2017
  11. Callum Roberts, Bethan C. O'Leary, Douglas J. McCauley, Maurice Philippe Cury, Carlos M. Duarte, Jane Lubchenco, Daniel Pauly, Andrea Sáenz-Arroyo, Ussif Rashid Sumaila, Rod W. Wilson, Boris Worm, Juan Carlos Castilla. (2017). Marine reserves can mitigate and Promote Adaptation to Climate Change. Proceedings of the National Academy of Sciences. Vol.114 (24), pp: 6167.
  12. James Watson, Dudley N. Segan D., and Marc Hockings (2014). The performance and potential of protected areas. Nature. Vol. 515, pp: 67