Climate Change Exam 1

Weather

The condition of Earth's atmosphere at a particular time and place.

Climate

The average weather conditions in a large area over a long period of time. Seen in averages, extremes, and statistics

Example of weather

It rained heavily all afternoon

Example of climate

Florida is hot and humid

What is climate change?

Any significant change in the Earth's climate over a long period.

What is global warming?

a gradual increase in the temperature of Earth's atmosphere

Latitude

Distance north or south of the equator which is 0 degrees latitude

Tropics (coordinates and definition)

30 degrees north to 30 degrees south, The warm parts near the middle

Mid-latitudes (coordinates and definition)

30 degrees to 60 degrees north and south, where we live

Polar regions

Cold parts at the ends of the earth

Longitude

Distance east or west of the prime meridian, measured in degrees

How to evaluate a source for accuracy or truthfulness?

Currency (info is up to date and appropriate for topic), Relevance(determine if source directly addresses your question and matches your required level of depth and intended audience), Authority(Look into the author's credentials, professional background, and institutional affiliations), Accuracy(Examine whether the claims are backed by strong evidence, data, and transparent citations), Purpose(Identify the motive behind the publication)

How do we know temperatures have been increasing?

Temperature observations, Temperature anomalies, Thermometers, Satellites, Migratory animal patterns, Ice melting, Sea levels rise, trees, ice cores, sedimentary rocks, Sediment core from the bottom of the ocean

Why do rising sea levels show that temperature increasing?

Ice is melting into the oceans and as oceans heat up, the water expands in volume

How do we know what temperatures were a long time ago?

Ice cores, Sedimentary rocks, Sediment cores from the bottom of the ocean, trees and their rings

How do know what temperatures were with sediment cores from the bottom of the ocean?

Paleoproxy is the dead stuff in the core. Microorganisms respond differently to temperature and when they die they sink to the bottom of the ocean, we can predict past temperatures based on their responses.

How has earths temperature behaved over the very long term

Earths temperature has always fluctuated naturally, however, past climate change has taken longer.

How carbon dioxide has behaved on earth over the very long term

The long-term trend in carbon dioxide concentrations have been fluctuating

Our current geological time period

The Holocene

Icehouse Climate

Conditions of cold average global temperatures, during which large areas are covered by glaciers

Greenhouse Climate

Refers to conditions of warm average global temperatures, during which there is little polar ice.

Milankovitch cycles

predictable variations in Earth's position in space relative to the Sun that affect climate

Glacial Period

A period of cooler climate that is characterized by the advancement of glaciers

Interglacial Period

A period of warmer temperatures between two ice ages.

How do Ice ages begin and end

begin when shifting continental plates block warm ocean currents and drop atmospheric carbon dioxide, while they end when changes in Earth's orbit and axis increase summer sunlight to melt ice sheets

What happens when you emit radiation

you lose energy

Temperature

A measure of how hot or cold something is.

wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Relationship between temperature and wavelength

Shorter wavelengths have more energy and therefore a higher temperature. Longer wavelengths have less energy and therefore a lower temperature

Relationship between temperature and the amount of energy radiated

Directly proportional relationship

energy budget

the net flow of energy into and out of a system

What type of energy comes in?

What type of energy goes out?

Energy emitted by the sun

Mostly Infared radiation, except for visible light which is the part we can see

Energy emitted by Earth

longer wavelengths (infrared) out

Energy emitted by the atmosphere

longwave (thermal) infrared radiation

The most abundant and important greenhouse gas

water vapor

The greenhouse gas that is focused on most

Carbon Dioxide

Why do we focus so much on CO2 as a greenhouse gas?

because it is the primary long-lived driver of human-induced global warming. Long atmospheric lifespan, Cumulative warming impact, Scale of human emissions, Amplifying feedback loops, and its comparison to other gases

How greenhouse gases work

They "trap" heat energy, and are transparent to higher frequency visible light, but opaque to lower frequency infrared (heat) radiation. Meaning they let incoming light energy from the Sun through, but instead of letting the outgoing infrared energy pass through them out into space, they absorb it. When things absorb energy, they heat up. As the gases heat up, they re-radiate some of that heat energy back outwards in all directions. Some of that energy is radiated downwards, back towards the Earth's surface, thus heating the surface up more than it otherwise would.

Why is it colder at the top of the mountain than at the bottom?

air pressure decreases at higher altitudes, causing rising air to expand and cool

How does the atmosphere affect the temperature of 2 different planets in space?

An atmosphere controls a planet's temperature by trapping heat through greenhouse gases, while albedo and oceans determine how much sunlight is reflected or absorbed. Oceans absorb vast amounts of solar energy rather than reflecting it. Bright ice and clouds reflect a large portion of incoming sunlight back into space, keeping polar regions cool

What is the biggest forcing in the earth system?

The Sun is the primary forcing

Forcings

a climate forcing is an upset in Earth's energy balance; can be internal or external.

Feedbacks

in climate studies, processes in which a natural or anthropogenic driver affects the climate system by a certain amount, as measured by a specified quantity, which, in turn, changes the first quantity

Which forcing is changing the most?

The biggest change has been the greenhouse gases we have added to the atmosphere, which keep heat from escaping the Earth

Positive Forcings

warming effect

Negative forcings

make earth cooler

Example of a Positive Forcing

Burning fossil fuels like coal, oil, and gas adds massive amounts of carbon dioxide to the atmosphere, thickening the thermal blanket that traps outgoing heat

Example of a Negative Forcing

Deforestation or agricultural shifts can replace dark, heat-absorbing forests with lighter crops or surfaces that reflect more sunlight away from the Earth

positive feedback

Feedback that tends to magnify a process or increase its output.

negative feedback

a mechanism of response in which a stimulus initiates reactions that reduce the stimulus

What role do feedbacks play in changing temperature?

either amplify or diminish temperature changes by acting as cyclical chain reactions in environmental and biological systems

What role do forcing play in changing temperature

act as drivers that create an imbalance in Earth's energy budget, changing global temperatures until a new balance is reached

Example of positive feedback

the ice-albedo feedback, where melting ice exposes darker surfaces that absorb more heat and cause further melting

Example of negative feedback

When Earth's surface temperature rises, oceans experience higher levels of evaporation. This extra moisture creates more low-level clouds, which reflect incoming solar radiation back into space and reduce surface warming

How do the ocean and atmosphere exchange carbon?

Surface Dissolution, Releasing Carbon (Degassing), Temperature Influence, Biological Pump, Physical Pump

The exchange of carbon dioxide between the land biosphere and the atmosphere

Photosynthesis, Respiration (Release), Decomposition (Release)

Ways that human activity disrupts the carbon cycle

by releasing vast amounts of stored carbon into the atmosphere and reducing the Earth's capacity to absorb carbon dioxide. This includes burning fossil fuels, deforestation, agricultural practices, Cement Production, and ocean acidification.

carbon cycle

the movement of carbon from the nonliving environment into living things and back

Blackbodies

an idealized physical object that absorbs all incoming electromagnetic radiation without reflecting or transmitting any of it

How does your temperature change when you lose energy?

Your temperature goes down

Where does your lost energy go?

Into the air, the objects your touching, your hair, your clothes, etc. Your surroundings!

How does the surroundings temperature change when you lose energy?

The temperature of the surroundings increases

Albedo

the percentage of incoming sunlight reflected from a surface

Molecular movement

Increasing the movement of molecules in an object

Radiations effect on molecular movement

It increases molecular movement

1st law of thermodynamics

the total energy of a system is conserved. Energy cannot be created or destroyed, only transformed or transferred

Physical pump (Carbon Cycle)

Large-scale ocean circulation and currents carry dissolved carbon from the surface down into the deep ocean, especially in high-latitude regions where cold, dense water sinks

Biological Pump (Carbon Cycle)

Microscopic marine organisms like phytoplankton use dissolved carbon dioxide and sunlight for photosynthesis. When these organisms and larger marine life die, they sink and carry carbon down into the deep ocean, locking it away for centuries

Temperature Influence (Carbon Cycle)

Cold polar waters absorb more carbon dioxide because low temperatures make the gas dissolve more easily. Warm tropical waters tend to release carbon dioxide back into the air.

Releasing Carbon (Degassing) (Carbon Cycle)

When deep ocean water rich in carbon is brought to the surface through upwelling or when surface water warms, carbon dioxide escapes back into the atmosphere

Surface Dissolution (Carbon Cycle)

Carbon dioxide gas from the atmosphere dissolves directly into the ocean surface when gas concentrations are higher in the air than in the water. Waves and wind-driven turbulence mix this dissolved gas into the upper layer of the ocean

Photosynthesis (Carbon Cycle)

Terrestrial plants pull carbon dioxide directly from the atmosphere. They use sunlight to turn it into sugars and organic matter for growth

Respiration (Carbon Cycle)

Plants, animals, and soil microbes break down organic molecules for energy. This metabolic process releases carbon dioxide back into the atmosphere

Decomposition (Carbon Cycle)

When plants and animals die, decomposers break down their tissues. This decay process also returns carbon dioxide to the air or integrates it into the soil

How does burning fossil fuels disrupt the carbon cycle?

It moves ancient, stored carbon from underground reservoirs directly into the atmosphere as CO2

How does deforestation disrupt the carbon cycle?

Cutting or burning down forests releases the carbon stored in trees back into the air while permanently removing the plants needed to absorb future CO2

How do agricultural practices disrupt the carbon cycle?

Tilling and plowing disrupt soil, causing organic matter to decompose rapidly and release trapped carbon, while livestock production generates large amounts of methane, a potent greenhouse gas

How does cement production disrupt the carbon cycle?

Manufacturing cement involves heating limestone (calcium carbonate), a chemical process that directly releases significant quantities of CO2 into the atmosphere

How does ocean acidification disrupt the carbon cycle?

Oceans absorb roughly half of excess anthropogenic CO2, lowering seawater pH and harming marine life like corals and shell-building organisms

Steps of the carbon cycle

Photosynthesis, Cellular Respiration, Decomposition, Combustion