APES 9

9.4: INCREASE IN GREENHOUSE GASSES

Why sea level is rising: thermal expansion and melting polar and glacial ice

Thermal expansion: water molecules move slightly further apart when they are heated

Melting polar and glacial ice: caused by increased greenhouse gasses and a warmer climate, with water flowing into the ocean

Environmental impacts of sea level rise: flooding of coastal ecosystems like estuaries (mangroves, salt marshes), loss of species that depend on arctic and tundra ecosystems (polar bears, reindeer, penguins), and loss of freeze-thaw cycle that glaciers go through, depriving surrounding ecosystems and human communities of water source

Human impacts of sea level rise: relocation of human population, increase in flood with higher insurance and repair costs, saltwater intrusion, and refugees forced to move inland

Vectors: living organisms (mosquitoes, ticks, fleas) that can transmit diseases from human to human or animal to human

Examples of vectors: malaria, zika, west Nile, dengue fever, cholera

Impact of warmer temperatures towards vectors; warmer temperatures allow insect-transmitted diseases to spread to parts of the world previously too cold, like the poles, making new human populations at risk