Exam #1 (Climate-101)

Question 1

What is weather?

Answer 1

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.

Question 2

What is climate?

Answer 2

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.

Question 3

What is the difference between climate and weather?

Answer 3

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.

Question 4

What is The Intergovernmental Panel on Climate Change (IPCC)?

Answer 4

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

Question 5

What is a system?

Answer 5

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.

Question 6

What is the climate system?

Answer 6

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.

Question 7

What is climate variability?

Answer 7

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.

Question 8

What is climate change?

Answer 8

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.

Question 9

What is global warming?

Answer 9

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.

Question 10

Describe the differences between climate variability, climate change, and global warming

Answer 10

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.

Question 11

What is energy balance?

Answer 11

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.

Question 12

What is radiative forcing?

Answer 12

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.

Question 13

What is climate forcing?

Answer 13

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.

Question 14

What is total solar irradiance?

Answer 14

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.

Question 15

What is obliquity

Answer 15

The tilt of Earth’s rotation axis with respect to the plane of its orbit.

Analogous to a spinning top that leans over.

Question 16

What is precession?

Answer 16

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.

Question 17

What is eccentricity?

Answer 17

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).

Question 18

What is an ice age?

Answer 18

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.

Question 19

What is albedo?

Answer 19

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.

Question 20

What is the greenhouse effect?

Answer 20

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.

Question 21

What are greenhouse gases?

Answer 21

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.

Question 22

What is water vapor?

Answer 22

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.

Question 23

What is carbon dioxide (CO2)?

Answer 23

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.

Question 24

What is climate feedback?

Answer 24

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.

Question 25

What is the carbon cycle?

Answer 25

The flow of carbon in various forms, e.g., as carbon dioxide, through the atmosphere, ocean, terrestrial and marine biosphere, and lithosphere.

Biogeochemical cycles like the carbon cycle involve material reservoirs (e.g., CO2 in the atmosphere), fluxes (material transferred between reservoirs, e.g., between the atmosphere and plants or soil), and sources and sinks (fluxes of material into or out of reservoirs).

Question 26

What is net radiative forcing?

Answer 26

The net outcome of all the direct forcings, together with positive and negative feedbacks.

Radiative forcing primarily comes from the greenhouse effect; negative feedback primarily comes from the warmer Earth radiating more, but positive feedback (primarily from clouds, reduced albedo, and water vapor) only partially offsets the additional radiation. The net radiative forcing is positive, leading to global warming.

Question 27

What is a climate tipping point?

Answer 27

A transition when Earth’s climate system abruptly moves between relatively stable states.

Example: possible runaway methane emissions from melting permafrost. Gov 101 uses “tipping point” more generically.

Question 28

What is an extreme weather event?

Answer 28

A weather event that is rare at a particular place and time of year.

Example: the 40” rainfall in Houston, TX, USA, from Hurricane Harvey in 2017. The generic term “extreme event” sees different usages in different fields.

Question 29

What is an extreme climate event?

Answer 29

The occurrence of pattern of extreme weather persisting for some time, e.g., over a season, especially if it yields an average or total that is itself extreme (e.g., drought or heavy rainfall over a season).

Example: the extraordinarily hot summer of 2023.

Question 30

What is a climate model?

Answer 30

A numerical representation of the climate system based on the physical, chemical, and biological properties of its components; their interactions and feedback processes; and accounting for some of its known properties.

Examples include Atmosphere Ocean General Circulation Models and more complex Earth System Models.

Question 31

What is a representative concentration pathway (RCP)?

Answer 31

A scenario that includes time series of emissions and concentrations of the full suite of greenhouse gases (GHGs), aerosols, and chemically active gases as well as land use/land cover.

Examples include the high emissions Scenario (RCP 8.5) and the low-emissions scenario (RCP 2.6), where the number is the estimated radiative forcing in Watts per square meter in 2100.

Question 32

What are shared socioeconomic pathways (SSPs)?

Answer 32

A collection of pathways that describe alternative futures of socio-economic development in the absence of climate policy intervention.

The combination of SSPs that describe societal evolution in the absence of climate policies with policy-impacted RCPs provides a framework for evaluating climate impacts and policy choices.

Question 33

What is climate mitigation?

Answer 33

Human intervention to reduce the sources or enhance the sinks of greenhouse gases.

The term “mitigation” can carry different meanings in different contexts. In the climate arena, it is “managing the unmangeable.” In others, it refers to actions taken to reduce hazard risk.

Question 34

What is climate adaptation?

Answer 34

The process of adjustment to actual or expected climate and its effects.

In the climate arena, adaptation is “managing the unavoidable.”

Question 35

What is a science deficit model?

Answer 35

The idea that the target audience has gaps in their knowledge of science, and that outreach and teaching can fill in these gaps.

Increasing science literacy doesn’t alter judgments people form because of their underlying value sytems. Climate communication must reach out to people “where they live.”

Question 36

What is SMART?

Answer 36

An acronym for Specific, Measurable, Achievable, Realistic, and Timely used to help guide goal-setting.

Adopting specific well-considered goals with associated metrics increases the likelihood of achieving the intended outcomes. In climate communication, “A” can stand for “audience-focused.”

Question 37

Define confirmation bias

Answer 37

The tendency to process information by looking for, or interpreting, information that is consistent with one’s existing beliefs.

Confirmation bias can manifest in people selecting examples that reinforce their perspective, e.g., for or against perceiving global warming as human-caused.