Every day, a quarter of the CO2 emitted by human activities is directed towards the ocean. This regulatory role that the oceans play in absorbing carbon dioxide is crucial, but it comes at a price, as the ocean is becoming acidic, that is, its pH is decreasingThis has profound implications for marine life and, consequently, for humans.
Ocean Acidification: A Growing Problem
Acidification occurs because the carbon dioxide (CO2) Acidification reacts with seawater to form carbonic acid, which lowers the pH. By 2100, ocean pH is projected to drop by 0,38 units compared to XNUMXth century levels. This may seem like a small change, but it is devastating to many forms of marine life. Acidification profoundly affects organisms that rely on calcium carbonate, such as corals, mollusks, and some types of plankton, limiting their ability to form skeletons and shells. These systems are vital, as calcifying organisms form the basis of marine food chains.
The disruption of these organisms also affects larger animals that depend on them as a food source. In addition, coral reefs, which provide shelter and sustenance to thousands of species, will be among the most immediate victims of acidification.
Warming and Alteration of Ocean Currents
El ocean warming is another of the main consequences of climate change. This phenomenon affects both the surface and the deepest parts of the ocean and is causing drastic changes in the habitats of many species. Warm water can reduce the amount of dissolved oxygen in the water, affecting aquatic life. ocean currents are also affected, producing changes in the migration patterns of marine species and in the circulation of nutrients essential to the ecosystem.
For example, one of the most important currents, the Gulf Stream, is showing signs of an “unprecedented” slowdown. This not only affects the species that depend on these currents to reproduce or move, but also has consequences for the global climate, as it modifies rainfall in some areas and alters air temperatures.
Ice Melt and Sea Level Rise
Another critical factor is the melting of glaciers and polar ice caps due to global warming. This process is contributing to the Rising sea levels, which is profoundly changing coastal landscapes and threatening the existence of thousands of communities that depend on the sea for their livelihood. Recent data indicate that sea level has risen by about 20 cm since the XNUMXth century and could continue to rise at an alarming rate.
This increase is driven mainly by two factors: thermal expansion of water when heated and the melting of ice capsAs sea levels rise, flood risks increase, threatening human populations living near the coasts. According to the IPCC, low-lying coastal areas are home to 10% of the world's population, mostly in vulnerable regions such as Pacific islands, which could disappear under water in the coming decades.
Impact on Biodiversity and the Food Chain
Marine biodiversity is under constant threat due to the combined effects of acidification, warming water and altered ocean currents. As a result, many species are migrating to colder waters in an attempt to escape changing conditions in their traditional habitats. Organisms that rely on constant ocean temperatures, such as corals and plankton, face critical challenges to their survival.
The loss of biodiversity also directly affects human food security. Around 3.000 million people They rely on fish as their main source of protein. However, with fish stocks declining due to overfishing and climate change, this food supply is at risk. Organisms such as corals, which form a crucial part of ecosystems, are especially vulnerable to rising ocean temperatures and acidification, which affects the entire food chain.
Consequences for Human Health and the Economic Sector
Climate change indirectly affects human health. As the oceans absorb more heat and CO2, conditions become more favorable for pathogens and bacteria that can thrive in warm waters. Waterborne diseases, such as cholera, could also increase if effective measures are not taken. This is in addition to the direct impact on sectors such as fishing and tourism, key sources of income for coastal communities. coral reef tourism, for example, could decline significantly due to coral bleaching. The total damage to coral reefs is estimated to cost billions of dollars annually.
Urgent Solutions and Mitigation Actions
To mitigate the effects of climate change on the oceans, it is crucial to comply with the Paris agreements and limit global warming to less than 1,5ºC. Decarbonising key sectors such as shipping and drastically reducing carbon dioxide emissions are key steps. Local solutions are also being implemented, such as restoring mangroves, which protect coastlines from storms and help absorb carbon.
Companies play a key role in the fight against climate change, being able to adopt a blue economy, which promotes the sustainable use of ocean resources. Likewise, continued scientific research is vital to continue monitoring changes in the ocean, with special attention to the acidification, sea level rise and changes in ocean currents.
The decisions we make in the next decade will determine our future. Protecting the oceans is not just a matter of environmental conservation, but also of ensuring human survival.