BBC Global Climate Change 2025 - Examining Ocean Floor Sediments Practice Test with Free Practice Questions

Thermal expansion refers to the phenomenon where water expands as it warms, which is a direct consequence of global temperature increases due to climate change. As the oceans absorb heat from the atmosphere, the water molecules move more vigorously and take up more space, leading to an increase in the volume of water. This results in rising global sea levels, which can have widespread effects on coastal communities, ecosystems, and infrastructure.

In contrast, stronger ocean currents, increased ocean acidity, and decreased fish populations are impacted by climate change but are not direct results of thermal expansion. Stronger currents can be influenced by various factors, including changes in wind patterns and temperature gradients. Ocean acidity is primarily affected by the absorption of carbon dioxide in seawater rather than thermal changes, and fish populations can be affected by many factors including habitat changes and overfishing, rather than solely by the rise in sea levels caused by thermal expansion.