Climate Change and Biomes Overview

Climate Change

• Consensus among scientists that climate change is a significant and pressing issue.
• Mauna Loa Observatory measures atmospheric CO2 levels; pre-industrial levels were 280 ppm or less.
• 68% of Earth's land mass lies in the Northern Hemisphere, which also houses 90% of the global human population.
• Seasonal variations in CO2 levels are observable.
• Earth's average temperature would be -18°C without the atmosphere, currently around -15°C.
• Global annual CO2 emissions vary by sector and country, with specific data for Australia.
• Potential sea level rise is projected at 3°C global temperature increase.
• Climate Change Performance Index evaluates countries' emissions and climate protection efforts.

Biomes Overview

• Six principal biomes include Freshwater, Marine, Desert, Forest, Grassland, and Tundra.
• Distinction between biotic factors (living organisms) like flora, fauna, fungi, and bacteria, and abiotic factors (non-living elements) such as fire, water, temperature, sunlight, and air.

Climate Influencing Factors

• Climate represents long-term weather patterns; weather refers to short-term atmospheric conditions.
• Latitude influences sunlight and heat; regions closer to the equator receive more.
• Distance from oceans affects moisture levels; areas inland tend to be drier with extreme temperature swings.
• Temperature decreases with altitude at a rate of approximately 0.65°C for every 100 meters gained.
• Topography, such as mountains, creates rain shadow effects, altering rainfall distribution.
• Prevailing winds significantly impact local weather conditions.

Photosynthesis

• The photosynthesis equation is 6CO2 + 6H2O + Light energy → C6H12O6 (Glucose) + 6O2.
• Trees utilize oxygen during cellular respiration at night, balancing the oxygen output during the day.

Net Primary Productivity (NPP)

• NPP measures plant growth and ecosystem productivity; influenced primarily by temperature and moisture levels.

Energy Flows in an Ecosystem

• The sun is the primary energy source for ecosystems.
• 90% of energy is lost at each trophic level due to movement, heat, respiration, growth, waste, and reproduction.
• Large animals are often herbivores or secondary consumers due to energy constraints.
• Energy pyramid structure: Producers (plants) → 1st order consumers (herbivores) → 2nd order consumers (omnivores) → 3rd order consumers (carnivores) → 4th order consumers (apex predators).
• Decomposers, including fungi and bacteria, are essential for nutrient recycling within ecosystems.