Title: Unit 13 Glossary
Course: BIS 105 Environmental Biology > Section: BIS 105 Environmental Biology

Unit 13 Glossary

Terms

Term | Definitions
active transportation | Means of transportation that involve more physical activity, typically considered walking, biking, and use of public transit (bus and rail).
albedo | A measure of how reflective a surface is. A perfectly black surface has an albedo of 0, while a perfectly white surface has an albedo of 1.
anthropogenic | Caused or produced by humans.
axial precession | The movement in the axis of rotation, which change in the direction of Earth's axis of rotation relative to the stars.
axial tilt | The angle between a planet's axis of rotation and the line perpendicular to the plane in which it orbits. The Earth's current axial tilt is 23.5 degrees.
car sharing | A program that allows for more than one person to have use of a car. Generally, it works like a short-term (hourly) car rental service. Cars are located near residences and work places to facilita ...
carpooling | When two or more people travel to and from proximal departure and arrival destinations in the same vehicle.
climate | The average of the weather.
cretaceous period | The period between 65 and 145 million years ago, which was the final period of Earth's history that included dinosaurs.
eccentricity | A measure of how much an ellipse departs from circularity.
glacial period | A long period of time in which ice sheets and glaciers are advanced in their extent.
greenhouse effect | The process by which the atmosphere acts to trap heat, warming the climate.
greenhouse gases | Those gases in the atmosphere that warm the climate, most importantly, water vapor, carbon dioxide, methane, and ozone.
ice sheets | Glaciers big enough to cover a continent. Currently, ice sheets are found in Antarctica and Greenland, but during glacial periods, ice sheets have covered other land masses, including North Americ ...
infrared spectrum | Radiation just below the range of wavelengths visible to the human eye. Also referred to as thermal radiation.
insolation | The measure of the amount of solar radiation falling on a surface.
interglacial period | The warm periods of the Quaternary in which glaciers and ice-sheets retreat. These occur between the longer glacial periods.
isotopes | Atoms that have same number of protons but different numbers of neutrons. This means that they are the same element (e.g. oxygen), have the same chemical properties, but different masses.
last glacial maximum | The time at which ice sheets were at their greatest extent during the latest glacial period.
lightweighting | Making a product out of materials that weigh less than were previously used.
low-emittance coatings | Microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow.
Milankovitch Cycles | Periodic variations in the Earth's orbit that influence its climate. These cycles are named after Milutin Milankovitch, a mathematician who quantified the theory.
permafrost | Soil that has a temperature that has remained below freezing (0°C or 32°F) for at least two years
phantom load | Refers to the electrical load of appliances and chargers when they are not in use but plugged in, as they still draw power but provide no service.
positive feedback | A runaway process which amplifies the effect of an initial change.
proxy data | Information about the climate that accumulates through natural phenomena.
quaternary period | The most recent geological period, spanning the time from 2.6 million years ago to today.
radiative forcing | Change in net irradiance (an energy flux) measured at some boundary. For this text the boundary is typically at the surface of the earth or the top of atmosphere. A positive change indicates warmi ...
snowball earth | A condition in which the entire planet is covered in ice, last thought to have happened 650 million years ago.
U-factor | The rate of heat loss is indicated in terms of the of a window assembly. The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating properties.
visible spectrum | Radiation that is in the range of wavelengths that is visible to the human eye.
watts per square meter (W/m^2) | Energy (Joules) per second moving through a surface (square meter). A flux of energy through a surface area.
weather | A description of the short term state of the atmosphere.
wedge approach | A way of expressing the concept that there is no one solution to the challenge of reducing greenhouse gas emissions. Each technology, action or change is represented by a triangular wedge in a cha ...
well-mixed gas | A gas that can be found at the same concentration throughout the lower atmosphere regardless of location.