Glossary
CFCs (chlorofluorocarbons)
Synthetic compounds once widely used in refrigerants and aerosols that were found to deplete the stratospheric ozone layer.
Example:
The Montreal Protocol was an international agreement designed to phase out the production of CFCs to protect the ozone layer.
Carbon Dioxide (CO2)
A major greenhouse gas naturally present in the atmosphere, but significantly increased by human activities like burning fossil fuels.
Example:
The fizz in your soda is due to dissolved Carbon Dioxide, which is released when you open the bottle.
Denitrification
A microbial process that converts nitrates back into nitrogen gas (N2), releasing it into the atmosphere.
Example:
In waterlogged soils, bacteria perform denitrification, which can reduce the availability of nitrogen for plant growth.
Exosphere
The outermost layer of Earth's atmosphere, where it gradually merges with outer space, extending from about 700 km to 10,000 km.
Example:
Many Earth-orbiting satellites, including the International Space Station, operate within the Exosphere.
Greenhouse Gases
Gases in Earth's atmosphere that trap heat, contributing to the greenhouse effect and global warming.
Example:
Reducing our reliance on fossil fuels is a key strategy to lower the concentration of Greenhouse Gases in the atmosphere.
Mesosphere
The atmospheric layer above the stratosphere, extending from about 50 km to 80 km, where temperatures decrease with altitude.
Example:
Most meteors burn up upon entering Earth's Mesosphere, creating visible streaks of light in the night sky.
Methane (CH4)
A potent greenhouse gas, much more effective at trapping heat than CO2 over a shorter period, released from sources like agriculture and fossil fuel extraction.
Example:
Landfills produce significant amounts of Methane as organic waste decomposes anaerobically.
Nitrogen (N2)
The most abundant gas in Earth's atmosphere, making up approximately 78% of its volume.
Example:
While we breathe in a lot of Nitrogen, our bodies don't use it directly from the air; it needs to be 'fixed' into usable forms by bacteria.
Nitrous Oxide (N2O)
A powerful greenhouse gas primarily emitted from agricultural activities (like fertilizer use) and industrial processes.
Example:
The use of synthetic fertilizers in farming can lead to the release of Nitrous Oxide into the atmosphere.
Oxygen (O2)
A vital gas for most life forms on Earth, comprising about 21% of the atmosphere.
Example:
Scuba divers rely on tanks filled with compressed air, rich in Oxygen, to breathe underwater.
Ozone (O3)
A gas molecule composed of three oxygen atoms; in the stratosphere, it forms a layer that absorbs harmful UV radiation.
Example:
Scientists monitor the Ozone layer over Antarctica to track its recovery after the phase-out of ozone-depleting substances.
Photosynthesis
The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll, converting carbon dioxide and water into glucose and oxygen.
Example:
Forests are crucial for global photosynthesis, acting as massive carbon sinks and oxygen producers.
Stratosphere
The atmospheric layer above the troposphere, extending from about 10 km to 50 km, containing the ozone layer.
Example:
High-altitude weather balloons can reach the Stratosphere to collect data on atmospheric conditions.
Thermosphere (Ionosphere)
The atmospheric layer above the mesosphere, extending from about 80 km to 100 km, characterized by increasing temperatures due to solar radiation and containing charged particles.
Example:
The beautiful aurora borealis and australis are caused by solar particles interacting with gases in the Thermosphere.
Troposphere
The lowest layer of Earth's atmosphere, extending from the surface up to about 10 km, where all weather occurs.
Example:
Commercial airplanes typically cruise in the upper part of the Troposphere to avoid turbulence and save fuel.
Water Vapor (H2O)
The gaseous phase of water, varying greatly in concentration in the atmosphere and playing a key role in weather patterns and the greenhouse effect.
Example:
On a humid summer day, the high amount of Water Vapor in the air makes it feel sticky and muggy.