Ocean Acidification

Summary

This video explains the crucial role of carbon dioxide (CO₂) in Earth’s atmosphere, focusing on its impact on ocean chemistry. As CO₂ dissolves in the ocean, it forms carbonic acid, leading to ocean acidification, which harms marine life, especially shell-building animals. The rise in CO₂ levels, primarily from human activities, is also driving global warming. Warmer temperatures reduce the ocean's ability to absorb CO₂, adding complexity to the issue. While the full consequences are uncertain, the video emphasizes the need to understand and address these environmental challenges to protect our planet.

Takeaways

• 😀 Earth's atmosphere is made up of 78% nitrogen, 21% oxygen, and just 0.04% carbon dioxide, but CO2 plays a crucial role in maintaining Earth's temperature.
• 🌍 Carbon dioxide is released by natural processes like respiration, decomposition, volcanic eruptions, and human activities such as burning fossil fuels.
• 💧 The ocean absorbs about 25% of atmospheric carbon dioxide, affecting the water's chemistry.
• 🔬 When CO2 dissolves in water, it forms aqueous CO2 and reacts to produce carbonic acid (H₂CO₃), which can split into hydrogen ions and bicarbonate.
• ⚖️ The CO2-carbonic acid reaction is reversible, meaning it can shift depending on environmental stress or changes in CO2 concentration.
• 🌡️ Increased CO2 leads to more carbonic acid in the water, which increases acidity and contributes to ocean acidification.
• 🐚 Ocean acidification makes it harder for shell-building creatures like mollusks and corals to form shells, as hydrogen ions compete with calcium for carbonate ions.
• 🌊 Ocean pH has dropped from 8.2 to 8.1 since the industrial revolution, a 25% increase in acidity, threatening marine ecosystems.
• 🔥 Human activities, especially burning fossil fuels, are driving the increase in atmospheric CO2 and global temperature rise.
• 🌡️ Rising global temperatures may reduce the ocean's ability to absorb CO2, complicating the process of ocean acidification and its effects on marine life.

Q & A

What percentage of Earth's atmosphere is composed of nitrogen?

Nitrogen makes up about 78% of Earth's atmosphere, or 780,840 parts per million.

How much of Earth's atmosphere is made up of oxygen?

Oxygen makes up about 21% of Earth's atmosphere, or 209,500 parts per million.

What is the role of carbon dioxide in Earth's atmosphere?

Carbon dioxide plays a crucial role in keeping Earth hospitable by contributing to the greenhouse effect, which helps maintain temperatures suitable for life.

How is carbon dioxide released into the atmosphere?

Carbon dioxide is released into the atmosphere through respiration from plants and animals, the decomposition of organic matter, burning fossil fuels, forest fires, volcanic eruptions, and some industrial processes like cement production.

What happens when carbon dioxide dissolves in the ocean?

When carbon dioxide dissolves in the ocean, it forms aqueous carbon dioxide. A small portion reacts with water to create carbonic acid, which can break down into hydrogen ions and bicarbonate.

How does Le Chatelier’s Principle relate to carbon dioxide in the ocean?

Le Chatelier’s Principle explains that when the concentration of carbon dioxide increases, the system responds by creating more carbonic acid and bicarbonate to relieve the stress, shifting the reaction toward more acidic conditions.

What is ocean acidification?

Ocean acidification refers to the decrease in pH levels of the ocean caused by the absorption of excess atmospheric carbon dioxide. It makes the ocean more acidic and harms marine life, particularly organisms that build shells.

How does ocean acidification affect marine organisms that build shells?

Ocean acidification reduces the availability of carbonate ions needed by shell-building organisms like mollusks and corals. The increased hydrogen ions bond with carbonate ions, forming bicarbonate instead, making it harder for these organisms to form shells.

What has been the change in ocean pH levels since the industrial revolution?

Since the industrial revolution, ocean pH levels have decreased from 8.2 to 8.1. While this may seem like a small change, it represents a 25% increase in ocean acidity.

How does global warming affect the solubility of carbon dioxide in the ocean?

As ocean temperatures rise due to global warming, the solubility of carbon dioxide decreases. Warmer waters are less able to absorb CO2, which could slow down the rate of ocean acidification.

Why is it difficult to predict the exact effects of ocean acidification and global climate change?

The effects are difficult to predict because the system involving the atmosphere, ocean, and Earth’s crust is complex, with many interrelated factors. The behavior of these systems in response to changes in temperature and CO2 levels is not fully understood.