Environmental Science Revision: Earth Systems, Cycles and Climate Change

What is the atmosphere composed of?

Nitrogen 78%, Oxygen 21%, Argon 1%, Carbon dioxide and other gases

What are the layers of the Earth's atmosphere?

Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere

Why is the atmosphere important?

Contains oxygen and carbon dioxide essential for all life, protects Earth from UV radiation, interacts with other spheres, helps keep Earth's temperature relatively constant.

What happens to temperature and pressure as you go up in the atmosphere?

Pressure will decrease; temperature will decrease then increase depending on the layer.

What are the differences between the lithosphere, hydrosphere, and biosphere?

Lithosphere: upper part of the crust and mantle; Hydrosphere: all water on Earth; Biosphere: all life on Earth.

What are the 7 processes that carbon is cycled throughout the Earth?

Photosynthesis, Transfer through the food chain, Respiration, Flatulence and decomposition, Fossil fuel formation, Combustion, Diffusion into the ocean and limestone formation.

What is the difference between carbon sinks and sources? Give 2 examples.

Carbon sink: stores carbon (e.g., photosynthesis, soil); Carbon source: releases carbon (e.g., animal respiration, burning fossil fuels).

What type of nitrogen is found in the atmosphere?

Nitrogen gas - N2

Where is nitrogen found in the Earth?

Atmosphere: Nitrogen gas - N2; Biosphere: Amino acids and DNA; Hydrosphere: Nitrates in water; Lithosphere: Nitrates from decomposition.

What is nitrogen fixation?

The conversion of atmospheric nitrogen (N2) into a compound useful for organisms, done by lightning or nitrogen-fixing bacteria.

What are the main components of the water cycle?

Transpiration, Percolation, Evaporation, Condensation, Precipitation.

What are the most common greenhouse gases?

Water vapour (H2O), Carbon dioxide (CO2), Nitrous oxide (N2O), Methane (CH4).

How do humans release carbon dioxide?

Burning fossil fuels, deforestation, industrial processes.

What's the difference between a glacial and interglacial period?

A glacial period has reduced temperatures for thousands of years; an interglacial period has warming climate for a sustained time.

What is climate change?

A long-term change in Earth's climate patterns, evidenced by rising global temperatures.

What is percolation in the water cycle?

The movement of water through soil and rock layers into groundwater.

What is the natural greenhouse effect?

The process where gases in the atmosphere trap heat, keeping Earth warm enough to support life.

What is the enhanced greenhouse effect?

The increase in heat trapped by greenhouse gases due to human activities.