How pollution is changing the ocean's chemistry | Triona McGrath

Summary

This speech highlights the vital role oceans play in sustaining life on Earth, from providing oxygen and food to regulating climate. However, it warns of the growing threat of ocean acidification due to the absorption of excess carbon dioxide from human activities. The speaker explains how this process is altering ocean chemistry, causing harm to marine species, including corals and shellfish. The talk urges immediate action to reduce carbon emissions, emphasizing that while ocean acidification is inevitable, we can still slow its progression to protect future generations and marine ecosystems.

Takeaways

• 🌊 The oceans cover two-thirds of the planet and are crucial for providing oxygen, moderating climate, and supporting jobs, medicine, and food sources.
• 🌍 The oceans have absorbed 25% of all carbon dioxide emissions, which is changing their chemistry and leading to ocean acidification.
• 📉 Ocean acidification refers to the decrease in seawater pH due to the absorption of excess carbon dioxide from the atmosphere.
• 📊 Scientists have been monitoring ocean acidification for over two decades, noting an increase in ocean acidity of 26% since pre-industrial times.
• 🌡️ Ocean acidification is happening globally, including in Ireland, where local scientists have observed the same trends as in major ocean time-series sites.
• 🐚 Increased ocean acidity reduces the availability of carbonate ions, which are essential for marine species like crabs, mussels, oysters, and corals to build their shells.
• 🦐 The shells of key species like the pteropod, a food source for many marine animals, are dissolving in seawater with lower pH, threatening the marine food chain.
• 🐠 Ocean acidification could disrupt marine ecosystems, potentially leading to a collapse of food sources for humans, such as shellfish and salmon.
• 🏝️ Coral reefs, which support 25% of all marine life, are at risk of dissolving due to increased ocean acidity, endangering marine biodiversity.
• 🚨 The speaker urges immediate action to reduce carbon dioxide emissions to slow down ocean acidification and prevent catastrophic impacts on marine life and human food sources.

Q & A

Why are the oceans important to our daily lives?

The oceans cover two-thirds of our planet, provide half of the oxygen we breathe, moderate our climate, and offer jobs, medicine, and food, including 20% of the protein for the global population.

What is ocean acidification?

Ocean acidification is the process where the ocean's pH decreases due to the absorption of carbon dioxide (CO2), making the water more acidic. It is often called the 'evil twin' of climate change.

How much carbon dioxide have the oceans absorbed?

The oceans have absorbed 25% of all carbon dioxide emitted into the atmosphere.

Why is ocean acidification happening alongside climate change?

As more CO2 is emitted into the atmosphere, more of it dissolves into the oceans. This increased absorption of CO2 changes the ocean's chemistry, leading to ocean acidification, which occurs simultaneously with climate change.

What has been the impact of ocean acidification since pre-industrial times?

There has been a 26% increase in ocean acidity since pre-industrial times due to human activities.

What is the projected increase in ocean acidity by the end of this century?

If carbon dioxide emissions are not reduced, ocean acidity is expected to increase by 170% by the end of this century.

How does ocean acidification affect marine life that build shells, like crabs and corals?

As ocean acidity increases, the concentration of carbonate ions in seawater decreases, making it harder for species like crabs, mussels, oysters, and corals to form their shells. In extreme cases, their shells may begin to dissolve.

What example was given of a species affected by ocean acidification?

A pteropod, also known as a sea butterfly, had its shell almost completely dissolve after 45 days in seawater with a pH expected by the end of this century.

Why are coral reefs important, and how are they threatened by ocean acidification?

Coral reefs support 25% of all marine life. By the end of this century, 70% of cold-water corals may be surrounded by seawater that is dissolving their structures due to ocean acidification.

What actions can be taken to slow down ocean acidification?

The key to slowing down ocean acidification is reducing carbon dioxide emissions. This requires efforts from individuals, industries, and governments to mitigate both global warming and acidification.