Climate Change and Marine Ecosystems

The oceans absorb a significant amount of anthropogenic CO2 emissions and thus play a key role in global biochemistry and climate regulation. However, rising atmospheric CO2 levels and climatic changes are greatly impacting marine ecosystems, the communities that depend on them and the very ability of the oceans to absorb this greenhouse gas. Severe climate change impacts on marine ecosystems and dependent societies include coral bleaching, ocean acidification, rising sea-levels, increasing invasive species, and increasing intensity of extreme weather events. These changes are harmful to the health and wellbeing of billions of peoples, species and ecosystems around the world. It is crucial that strategies be developed to cope with and adapt to these changes.

Climate change adaptation and resilience work is a key area for the IUCN Global Marine Programme. Through the Climate Change and Coral Reefs Marine Working Group (CCCR), the IUCN focuses on synergies between coral reef resilience science, management and policy. IUCN also promotes the establishment of networks of marine protected areas because inter alia they may serve as key tools to enhance adaptation and resilience of marine ecosystems to the harmful effects of climate change while also protecting biodiversity and allowing for the rebuilding fish stocks in support of sustainable fisheries. Adaptation and resilience are also key aspects of the IUCN Mangroves for the Future (MFF) project which focuses on coastal ecosystem management and capacity building for adaptation. This project uses climate change tools and methodologies for climate proofing, mainstreams climate change into pilot projects, and provides training and capacity building on climate change.

Furthermore, the IUCN forms part of the Reference User Group of the European Project on Ocean Acidification, a collaboration between major European research institutes to fill in gaps in knowledge and assess vulnerability of marine ecosystems to the threat of ocean acidification.

The IUCN Global Marine Programme has also focused on marine geo-engineering proposals that have been put forward as potential climate change mitigation tools. For example, proposals to sequester carbon dioxide through ocean fertilization are of concern as they may dramatically alter ocean chemistry and compromise important biological cycles. The IUCN Global Marine Programme urges extreme caution with regard to marine geo-engineering proposals and advocates a precautionary approach in policy making.