Humans are rapidly altering Earth’s climate. Since the Industrial Revolution, anthropogenic activities – including the burning of fossil fuels, deforestation and agriculture – have released enormous quantities of carbon dioxide and other greenhouse gases into the atmosphere. These emissions trap additional solar radiation, gradually raising the Earth’s average temperature in a processes known as global warming.
Unfortunately, the world’s oceans bear the brunt of anthropogenic carbon dioxide emissions. The ocean absorbs most of the excess heat building up in our atmosphere, which can be extremely detrimental to marine organisms that are highly adapted to a narrow temperature range. The ocean also absorbs a considerable amount of carbon dioxide from the atmosphere, which increases the acidity of seawater in a process known as ocean acidification. This phenomenon poses a significant threat to marine organisms that build calcium carbonate shells and skeletons, including corals and shellfish. Rising atmospheric and ocean temperatures are also driving global sea level rise due to the thermal expansion of seawater (warmer water takes up more space) and the melting of glaciers and ice sheets. Rapid sea level rise will damage coastal habitats and human infrastructure, increase the frequency and severity of coastal storms, and contaminate aquifers and agricultural lands.
Marine Conservation Institute works with partners from the scientific community, political arena, and coastal fishing and aquaculture industries to address the emerging threat that climate change poses to the marine ecosystems that we all depend on. We are currently collaborating with the Tulalip Tribes and the National Fisheries Conservation Center to model sea level rise projections for the Washington coast. This research helps us understand the likely extent of sea level rise in the Puget Sound region and the accompanying risks to human infrastructure. Importantly, we are also quantifying how projected sea level rise will affect coastal ecosystems, including key marsh and estuary habitats. New salt marsh habitat that is predicted to be created by sea level rise will likely act as ‘blue carbon’ hotspots that remove excess carbon dioxide and may alleviate the local effects of ocean acidification.
Protecting our oceans from the effects of ongoing and future climate change is essential. Reducing carbon dioxide emissions to zero overnight is highly unlikely, but working towards reduced emissions over the coming decades is imperative if we are to avoid the worst possible scenarios. In concert with reducing emissions, we urgently need to find innovative solutions to adapt to climate change, gain a better understanding of how climate change will affect marine ecosystems, and hedge our bets by protecting areas that are most likely to survive the coming changes to our oceans. Intact ecosystems free from disturbance from fishing and other stressors are more resilient, making effective marine protected areas our best protection against the threats posed by climate change. Marine Conservation Institute is launching the Global Ocean Refuge System (GLORES) to improve the quantity and quality of marine protected areas globally and safeguard marine biodiversity in the face of unprecedented climate change.
This issue of Current highlights ocean acidification, a term used to describe the ongoing global scale changes in seawater chemistry caused largely by human combustion of fossil fuels. Ocean acidification will have severe consequences for marine life and humankind, and has been nicknamed "climate change's twin.” The articles in this special issue focus on multiple facets of ocean acidification, including threats to marine organisms, economic implications for fisheries and ecosystem services, and policy options for mitigating negative impacts. Because the dangers posed by ocean acidification are so serious, responsible carbon policy must be implemented immediately at all levels of government and individuals must do their part to curtail carbon consumption, in the hope of safeguarding the future of our oceans.