Exam #1 (Climate-101) Flashcards
Preparing for the Climate Science & Vulnerability Assessment Exam
What is weather?
The state of the atmosphere at a particular place during a short period of time.
Conditions outside your home today: the atmospheric conditions that you can see, feel, and measure at a given place and time.
What is climate?
The average of weather for a given location and season, averaged over a period of time ranging from months to thousands of years or longer.
Example: 30-year average July precipitation in Chicago, IL, USA. More rigorously, climate is the statistical description in terms of the mean and variability of quantities of parameters such as temperature, precipitation, wind, humidity, cloudiness, etc.
What is the difference between climate and weather?
Weather is short-term and local. Climate involves averaging over at least months, e.g., a season, and may range from local to planetary.
Example: Climate guides your choice of clothes for a destination. Weather determines what you wear after you arrive.
What is The Intergovernmental Panel on Climate Change (IPCC)?
The United Nations body for assessing the science, related to climate change adaptation and mitigation options.
It provides policymakers with regular scientific assessments on climate change, its implications, and potential future risks as well as offers
What is a system?
A regularly interacting or interdependent group of items forming a unified whole.
For example, the climate system or an ecosystem. The concept of a system or systems appears in multiple modules.
What is the climate system?
The highly complex system consisting of five major components: the atmosphere (gases and particles), the hydrosphere (liquid water), the cryosphere (frozen water), the lithosphere (solid earth), and the biosphere (all forms of life) as well as the interactions among them.
What is climate variability?
The way aspects of climate (such as temperature and precipitation) differ from an average.
Climate variability results from natural causes and includes year-to-year or seasonal differences at a given location, as well as quasi-periodic changes such as the El Nino Southern Oscillation.
What is climate change?
Change in the state of the climate that can be identified (i.e., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer.
Climate change refers to long-term (years to centuries) change in meteorological and environmental conditions that alter the average or variability of weather patterns due to natural or human causes, or both.
What is global warming?
The gradual increase, observed or projected, in global surface temperature as one of the consequences of radiative forcing caused by anthropogenic emissions.
Example: Since 2014, every year has had global average temperatures warmer than any prior year in the instrumental record.
Describe the differences between climate variability, climate change, and global warming
Climate variability is relatively short term and natural. Climate change is long term and may or may not stem from natural causes. Global warming is a specific consequence of anthropogenic climate change.
Key conceptual destinction.
What is energy balance?
The balance between the total energy that enters, leaves, and accumulates within a system (such as an ecosystem).
Global warming, or global cooling, results from a long-term change in the balance of energy inputs into and outputs from the climate system.
What is radiative forcing?
The difference in amounts between incoming and outgoing energy in the climate system.
Because only radiation carries significant amounts of energy into or out of the Earth’s atmosphere, radiative forcing results from a lack of energy balance in the Earth’s atmosphere.
What is climate forcing?
An imposed, natural, or anthropogenic perturbation of the Earth’s energy balance with space.
Climate forcings, e.g., solar radiation or greenhouse gases, are the drivers of climate. They may tend to warm (“positive” forcing) or to cool (“negative forcing”) the climate.
What is total solar irradiance?
The power per unit area (Watts per square meter, W/sq m) of radiant energy at all wavelengths from the entire disk of the sun measured from the top of the atmosphere at 1 Astronomical Unit from the sun (i.e., Earth’s average distance).
This is the technical term that standardizes “solar radiation” as a climate forcing. Variations in total solar irradiance change the energy input side of the energy balance equation.
What is obliquity
The tilt of Earth’s rotation axis with respect to the plane of its orbit.
Analogous to a spinning top that leans over.
What is precession?
The cyclical change in the orientation of Earth’s rotational axis, seen as a circle slowly traced out by its pole.
Analogous to the phenomenon of “wobble” observed in spinning top that changes its orientation rather than falling over.
What is eccentricity?
Deviation of Earth’s orbit from circularity, leading to corresponding annual variation in the distance between Earth and the sun.
Earth’s orbit is elliptical, with the sun off-center (at one focus of the ellipse).
What is an ice age?
A long period of reduction in the temperature of Earth’s surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.
Ice ages result when the variatons of Earth’s orbit and orientation minimize solar radiation reaching the large land masses of the Northern Hemisphere for many thousands of years.
What is albedo?
The fraction of solar radiation reflected by a surface or object, often expressed as a percentage.
Albedo changes, e.g., from forest clearing or from decreases in ice cover, alter the amount of solar energy absorbed by the Earth’s surface.
What is the greenhouse effect?
The infrared radiative effect of all infrared-absorbing constituents in the atmosphere.
Many greenhouse gases, most importantly water vapor and carbon dioxide, absorb infrared (heat) radiation from the Earth’s surface, altering the energy balance of the atmosphere.
What are greenhouse gases?
Those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere, and clouds.
Examples: water vapor, carbon dioxide, methane, and nitrous oxide. GHG 102 provides additional detail.
What is water vapor?
The gaseous phase of water.
Although water vapor is a potent greenhouse gas, it readily condenses, so it provides climate forcing only for short times. However, because warmer temperatures allow air to carry more moisture, it acts as an important climate feedback.
What is carbon dioxide (CO2)?
A colorless, odorless, incombustible gas that is a product of respiration and combustion.
Unlike water vapor, carbon dioxide does not have a solid (dry ice) or liquid phase under normal atmospheric conditions on Earth. Consequently, it has a long atmospheric residence time, so ongoing anthropogenic emissions increase the greenhouse effect.
What is climate feedback?
An interaction in which a perturbation in one climate quantity causes a change in a second, and the change in the second quantity ultimately leads to an additional change in the first.
A negative feedback occurs when the initial perturbation is weakened by the changes it causes; a positive feedback occurs when the initial perrubation is enhanced. Example: higher termperatures incease the capacity air to carry moisture, resulting in a positive feedback that increases the initial warming.
