Oceans have become the planet’s carbon sink. Due to the excessive carbon absorbed by the oceans, dire consequences are happening which include melting of ice, maritime heat waves, rising sea levels, and acidification of oceans.
World Ocean Day: For more than 3.3 billion people globally relying on fish as a crucial protein source, and around 60 million working in fisheries and aquaculture industry worldwide, there is a looming threat of losing their major dietary source and livelihood with growing carbon levels in oceans. Oceans are absorbing way more carbon dioxide (CO2), than they can handle and as a result the whole aquatic ecosystem is under threat.
How oceans absorb CO2 and what would be the impact
According to nasa.gov.in, oceans have a similar ecosystem as that of land, where aquatic animals, including fish and other animals, breathe oxygen and give out CO2, and aquatic plants absorb CO2 and give out oxygen. The oceans absorb CO2 from air and human activities add to these rising carbon levels of the water bodies, especially the sea. The CO2 emitted into the air by vehicles, industries, planes and other human activities, ends up in the oceans when they absorb it through air. The oceans absorb about 25% of the CO2 emitted by burning fossil fuels and the exceeding amount of carbon absorption by oceans is causing ocean acidification.
The oceans, after absorbing the heat from the sun, enable their currents to move across the planet. Water currents within the oceans are just like highways which carry water around the earth. The phenomenon works in accordance with the cold water, which is found near the North and South Poles. The cold water from around the Poles sinks in and begins to flow, while the sun warms the hot water near the equator. When the temperature of the oceans keeps growing due to excess carbon absorption, the currents seize to flow, affecting the ocean ecosystem around the world. This could change the climate around various places on Earth.
Checking Ocean Health
The International Union for Conservation of Nature (IUCN), giving reference to the 2013 Fifth Assessment Report released by the Intergovernmental Panel on Climate Change (IPCC) raises the issue of excessive carbon absorption by oceans on their website. The said report unveiled alarming consequences of the enhanced greenhouse effect on our planet’s oceans and atmosphere. According to the report, the oceans have absorbed a staggering 93% of the excess energy, resulting in profound changes below the surface. Warming is now penetrating depths of 1,000 meters, leading to ocean stratification and disruptions in current patterns. Furthermore, expanding oxygen-depleted zones have been observed, causing shifts in the distribution and abundance of marine species.
On land, the effects are equally concerning, as inland glaciers and ice continue to melt, driving rising sea levels and endangering coastal regions. Shoreline erosion, habitat destruction, and saltwater intrusion are some of the significant impacts on coastal settlements. The report warns that sea levels may rise between 0.26 and 0.82 meters by the end of the century, depending on emission scenarios. Additionally, the growing acidity of the oceans, caused by CO2 emissions, threatens marine life by impairing the ability of organisms to form shells and skeletons and hindering their survival and reproduction. These findings highlight the urgent need for global action to mitigate climate change and protect our fragile ecosystems.
Impact of climate change on oceans
According to the information shared by the United Nations (UN) on their official website, oceans have become the planet’s carbon sink. Due to the excessive carbon absorbed by the oceans, dire consequences are happening which include melting of ice, maritime heat waves, rising sea levels, and acidification of oceans. The bad effects of these are not just restricted to the marine biodiversity, but the communities living across the coastal lines are also bearing the brunt. According to the UN’s estimates, about 680 million people reside in low-lying coastal regions across the world and more than 2 billion people reside in megacities built across coasts. Such a huge population is extremely vulnerable to the harmful effects of the rising carbon level in oceans, directly or indirectly.
The urgency to address the impacts of climate change on the world’s oceans cannot be overstated. The increasing frequency and intensity of marine heat waves pose a severe threat to coral reefs and marine ecosystems. If significant action is not taken, the very existence of coral reefs could be at stake. The rising temperatures also drive irreversible loss, with a high risk of extinction for more than half of the world’s marine species by the end of the century. It is crucial that we act swiftly to reduce greenhouse gas emissions, protect vital habitats, and ensure the sustainability of our oceans for future generations. The time for global collaboration and decisive measures is now.