Unit 2 - Changing Climate

Atmosphere

The layer of gases surrounding Earth.

Biosphere

The regions of Earth where life exists.

Cryosphere

Areas of Earth's surface where water is in solid form, like ice and snow.

Global energy budget

The balance between incoming and outgoing energy on Earth.

Insolation

Incoming solar radiation reaching Earth's surface.

Shortwave radiation

Solar energy with short wavelengths from the Sun.

Longwave radiation

Energy emitted by Earth back into the atmosphere, heat.

Climate forcing agents

Factors affecting Earth's energy balance.

Potential enhanced greenhouse (PEG)

Increased warming due to human activities amplifying natural effects, as described in the 80s by the oil industry.

The greenhouse effect

Trapping of heat by Earth's atmosphere to maintain temperature.

Natural greenhouse effect

Heat retention by naturally occurring gases like CO2 and water vapor.

Anthropogenic climate change

Climate changes caused by human activities.

Enhanced greenhouse effect

Additional warming due to increased greenhouse gases from human activities.

The Exxon position

Controversy around ExxonMobil's stance on climate change and fossil fuels - to emphasize uncertainty.

Fossil fuels

Non-renewable energy sources like coal, oil, and natural gas, which cannot be replenished in a human lifetime.

Energy deficit/surplus

Emitting more longwave radiation than receiving shortwave; the reverse.

Exosphere

Outermost atmospheric layer, merging into space.

Thermosphere

Layer above the mesosphere, with high temperatures.

Mesosphere

Middle atmospheric layer, where meteors burn up.

Stratosphere

Layer containing the ozone layer; above the troposphere.

Troposphere

The lowest atmospheric layer where weather occurs, as high as 20km from the Earth's surface.

Tropospheric ozone

Ozone in the troposphere, harmful pollutant contributing to smog.

Greenhouse gases

Gases like CO2, CH4, and N2O that trap heat in the atmosphere.

Ozone

A molecule of three oxygen atoms, protective in the stratosphere, harmful at ground level.

Methane

A potent greenhouse gas from agriculture and permafrost melt; GWP: 25.

Water

Essential greenhouse gas, contributing to Earth's natural warming.

Chlorofluorocarbons (CFCs)

Human-made chemicals damaging the ozone layer; GWP: 11,000.

Nitrous oxides

Greenhouse gases from fertilizers, agriculture, and industry; GWP: 310.

Internal forcing agents

Natural processes from within Earth's system like volcanic activity affecting climate.

External forcing agents

External factors like solar variations or asteroid impacts from outside Earth's system.

Ozone layer

Protective layer in the stratosphere absorbing harmful UV radiation, comprised of O3.

Climate

Long-term weather patterns in a region.

Weather

Short-term atmospheric conditions like temperature and precipitation.

Albedo

The reflectivity of Earth's surface.

Eustatic change

Global sea level changes due to water volume shifts.

Glacioeustatic change

Global sea level changes due to ice melt.

Sea ice

Frozen ocean water, reflective and critical for climate balance; goes through natural ablation and accumulation cycles, but melting overall, year to year.

Glaciers

Large masses of ice moving under their weight; goes through natural ablation and accumulation cycles, but melting overall, year to year.

Ice sheets

Vast layers of ice covering continents, like in Antarctica; goes through natural ablation and accumulation cycles, but melting overall, year to year.

Permafrost

Permanently frozen ground in polar regions; melting and releasing trapped methane (GWP 25).

Positive feedback loop (climate)

Processes amplifying initial climate changes, where the output accelerates the inputs.

Negative feedback loop (climate)

Processes reducing the effects of climate changes, leading to a dynamic equilibrium.

Carbon sink

Systems absorbing more carbon than they emit (e.g., forests, oceans).

Carbon source

Systems releasing more carbon than they absorb.

Carbon sequestration

The process of capturing and storing atmospheric carbon dioxide to reduce greenhouse gases.

Geosequestration

Storing captured carbon dioxide in underground geological formations.

Biosequestration

Capturing carbon dioxide through biological processes like tree growth or soil carbon storage.

Global Warming Potential (GWP)

Measure of a gas's heat-trapping effect over time, especially comparing greenhouse gasses heating potential and lifespan to that of carbon dioxide (GWP 1).

The solar constant

Average solar energy received by Earth.

Milankovitch cycles

Orbital changes influencing Earth's climate over tens of thousands of years.

Eccentricity

Shape of Earth's orbit, cycling every ~100,000 years.

Obliquity

Tilt of Earth's axis, cycling every ~41,000 years.

Precession

Wobble in Earth's rotation, cycling every ~26,000 years.

Direct insolation

Solar radiation reaching Earth's surface directly.

Diffuse insolation

Solar radiation scattered by the atmosphere.

Oblique rays

Sunlight hitting Earth at an angle.

Vertical rays

Direct sunlight striking Earth perpendicularly.

Solar spectrum

Range of all solar radiation wavelengths.

Solar cycles

Periodic changes in the Sun's activity, roughly every 11 years.

Sunspots

Cooler, darker spots on the Sun's surface.

Solar flares

Sudden bursts of energy from the Sun.

Volcanic winter

Cooling effect after volcanic eruptions blocking sunlight.

Solar evolution

The Sun's lifecycle and its impact on Earth's climate.

The Goldilocks zone

Earth's location in the solar system, allowing liquid water and life - expected to change as the sun ages over the next several billion years.

Global dimming

Reduced sunlight reaching Earth due to atmospheric particles.

Global warming

The long-term increase in Earth's average temperatures.

Global climate change

Broad changes in Earth's climate, including temperature and precipitation shifts.

The Montreal Protocol

An agreement to phase out ozone-depleting substances (especially CFCs, or Chlorofluorocarbons).

The ozone hole

Seasonal thinning of the ozone layer over Antarctica.

Year "Eighteen Hundred and Froze to Death"

1816, known for global cooling after the cataclysmic volcanic eruption of Mount Tambora in Indonesia, causing a year without a summer as far away as New England, where it snowed in July.

The water cycle

Movement of water through evaporation, condensation, and precipitation.

The nitrogen cycle

Movement of nitrogen through the atmosphere, soil, and living organisms.

The carbon cycle

Exchange of carbon between the atmosphere, biosphere, and oceans.

Deforestation

Removal of forests, impacting carbon sinks and climate.

Global agricultural system and climate change

Farming practices contributing to or affected by climate change - especially with reference to reduction of carbon sinks (deforestation) and nitrous oxide emissions.

Global transport system and climate change

Emissions from transport affecting climate.

Slash and burn

Agricultural method releasing carbon through forest clearing.

Meat production and climate change

Livestock farming contributing to greenhouse gas emissions; especially as we consider land used to supply feed, and refrigeration, processing, and logistics.

Beef production and climate change

Beef farming as a major methane and resource-intensive process; "burping cows".

The midnight sun

Continuous daylight in polar regions during summer. Also called the "polar day".

The polar night

24 hour cycles without sunlight.

Arctic and Antarctic Circle

Regions experiencing polar phenomena like the midnight sun.

Tropics of Cancer and Capricorn

Latitudes receiving direct sunlight at solstices.

Rainforests as carbon sinks

Dense forests absorbing CO2.

Phytoplankton as carbon sinks

Ocean organisms absorbing CO2 through photosynthesis.

High albedo

Surfaces like ice and clouds, deserts reflecting sunlight.

Low albedo

Dark surfaces like oceans, rainforests absorbing sunlight.

Methane sources

Permafrost melt, bogs, rice paddies, manure, cattle.

Nitrous oxide sources

Fertilizer, biomass burning, sewage treatment.

COP (Congress of Parties)

UN climate conferences addressing global warming (Started by UNFCCC after Rio '92).

Finite resource

Resources limited in supply, like fossil fuels.

Renewable energy

Energy from sources replenished naturally, like wind and solar.

Non-renewable energy

Energy from finite sources like coal and oil.

Fossil fuels

Coal, oil, and natural gas formed from ancient organic matter.

Petroleum

A liquid fossil fuel used in energy and industry.

Natural gas

A cleaner-burning fossil fuel.

Coal

A solid fossil fuel used primarily for electricity generation, especially in Asia.

Biomass

Organic material used for energy, like wood and koeng.

Biofuel

Fuel made from biological materials like corn or algae.

Biogas

Fuel made from decomposing organic material to produce methane.