9.4 - Increase in Greenhouse Gases

Question 1

Why sea level is rising

Answer 1

Thermal Expansion:
- Water molecules move slightly further apart when they’re heated
- All the water molecules of ocean moving slightly apart leads to sea level rising

Melting polar and glacier ice:
- Increased greenhouse gases lead to a warmer climate & more melting of ice sheets (at the poles and glaciers)
- This water flows into the ocean and leads to sea level rise

Question 2

Environmental Impacts of sea levels rising

Answer 2

• Flooding of coastal ecosystems like estuaries (mangroves, salt marshes)
• Loss of species that depend on arctic and tundra ecosystems (polar bears, penguins, reindeer)
• Loss of thaw-freeze cycle that glaciers go through, depriving surrounding ecosystems and human communities of water sourc

Question 3

Human Impact of sea levels rising

Answer 3

• Relocation of coastal human populations
• Increase in flood frequency = higher insurance and repair costs, lost property
• Saltwater intrusion (salt water pushing into ground water & contaminating wells)
• Refugees forced to move inland

Question 4

Disease Vectors

Answer 4

Vectors:
- Living organisms (usually mosquitoes, ticks, fleas) that can transmit diseases from human to human or animal to human
- Ex: malaria, Zika, West Nile, dengue fever, cholera

Extended Range:
- Warmer temperatures allow insect-transmitted diseases to spread to parts of the world previously too cold
- As the insect vectors expand their range further from equators, toward poles, new human pops. are at risk