EXAM 1
Carbon Sink
carbon reservoirs where anthropogenic carbon emissions ultimately end up
Carbon Source
carbon reservoirs which serve as the source of anthropogenic carbon emissions
Deep Water
cold, salty, dense water at the bottom of the ocean which is first created at the surface in the North Atlantic and near Antarctica.
Amino Acid
complex organic molecules which are the building blocks of proteins.
Carbon Reservoir
components of the Earth system that temporarily hold carbon
Damage Costs
costs associated with dealing with the negative impacts of climate change
DNA
deoxyribonucleic acid—a very complex organic molecule which contains the genetic information for life (chromosomes and genes). This molecule includes various "bases"—other less complex organic molecules. These molecules are strung together in two long chains which form the famous "double helix" form. James Watson and Francis Crick discovered the double helix in 1953 and were awarded the Nobel Prize in Physiology & Medicine.
Arid
dry conditions or a climate where evapotranspiration exceeds precipitation.
Dustfall
dust particles in the atmosphere which fall on glaciers and become incorporated into the glacial ice. It helps identify annual layers in ice cores, as less dust falls during the summer.
GMO
genetically modified organism. Organisms, including crop plants, which have been bred or genetically altered in order to reduce damage from pests. Alterations include resistance to herbicide sprayed on fields for killing unwanted plants, and the production by the plant of toxins intended to kill pests.
D-O Cycles or Events
rapid temperature fluctuations occurring during glacial events (but not interglacial events), especially in Greenland. They are identified in the O-18 record of glacial ice cores. D-O events are caused by changes in ocean circulation patterns in the North Atlantic, due to fluctuations in glacial meltwater disrupting the thermohaline circulation. [Dansgaard-Oeschger events]
Carbon Budget
refers to the balancing of carbon sinks and carbon sources.
Axial Tilt
the angle between Earth's orbital plane (the path it follows around the Sun) and its axis of rotation (which creates day & night). Earth's axial tilt varies over the course of 41,000 years between 22.5° and 24.5°. Currently, it is 23.5°. This is one of the three astronomical cycles which drive glacial cycles. The tilt is due to the gravitational pull of the moon, and it is responsible for the seasonal changes we experience on Earth.
Atom
the basic unit of a chemical element. Consists of protons and neutrons found in the nucleus, and electrons surrounding the nucleus.
Evapotranspiration
the combination of water evaporated by heat energy in the air and water transpired by plant action and released into the atmosphere.
abatement cost
the cost of adopting a new alternative energy technology or energy-saving mechanism. Technologies with negative abatement costs are those which result in net savings (the energy saved by adopting that technology is worth more than the cost associated with implementing the technology).
Eccentricity
the degree to which Earth's orbit around the Sun is a perfect circle or highly eccentric (oval-shaped). The eccentricity varies over the course of 100,000 years between perfectly circular and highly eccentric. Currently, it is close to circular. This is one of the three astronomical cycles which drive glacial cycles. The eccentricity is due to the gravitational pull of the other planets.
Anomaly
the difference from the long-term trend. Think about temperature.
Cyanobacteria
the first form of photosynthetic life. They are bacteria in the domain of Bacteria. Also known as "blue-green algae." Important for producing oxygen in Earth's early atmosphere.
agriculture
the growing of crops and raising of animals for food
Carbon Fertilization
the increased growth of plants grown under atmospheres with more CO2.
Bicarbonate
the major form of carbon in ocean water. Used by organisms such as plankton to create calcium carbonate. Also released by the weathering of carbonate rocks. Chemical composition: HCO3-
biodiversity
the number and variety of different species existing in a location.
Albedo
the percent of incoming solar radiation which is not absorbed, but rather reflected away, by an object. Earth's overall albedo at present is 30% (0.30).
Carboniferous Period
the period 360 to 290 MYA which was marked by very high atmospheric oxygen levels (35%).
Bombardment
the period in early Earth's history when asteroids regularly struck Earth. There was a heavy bombardment period until 4.45 BYA and sporadic bombardment until 3.85 BYA.
Greenhouse Effect
the physical process by which longwave radiation emitted by the Earth is absorbed in the atmosphere by greenhouse gasses and re-emitted toward Earth's surface, thereby causing warming. There is a natural greenhouse effect and an anthropogenic greenhouse effect. The process is the same, but the latter refers to the amount of warming attributable to the greenhouse gasses which humans have emitted to the atmosphere.
Bering Land Bridge
the piece of land connecting Asia with North America (modern day Russia and Alaska) which become exposed during the last glacial event due to lower sea levels, and which early humans used to first colonize the Americas.
Aphelion
the point in Earth's orbit when it is furthest from the Sun. Currently, this occurs during the Northern Hemisphere's summer. When aphelion occurs is a key driver of insolation and thus glacial cycles.
Cambrian Explosion
the rapid evolution of multi-cellular life that occurred 544 MYA and marked the transition from the Pre-Cambrian Eon to the Phanerozoic Eon.
Big Bang
the rapid expansion which marked the beginning of the universe ~14 billion years ago.
Glacial Cycles
the regular glacial and interglacial events occurring within one of Earth's 5 major glacial periods. They are defined by the regular expansion and contraction of ice sheets during the glacial period. The current glacial period, the Pleistocene, has had ~20 glacial cycles. These are driven primarily by astronomical cycles affecting insolation.
Equilibrium
the tendency of the state of an attribute to be maintained over time. These states can be stable or unstable.
Cenozoic
the third Era of the Phanerozoic Eon, occurring 65 MYA to Present. The climate cooled throughout the Cenozoic, leading to the 5th and final major glacial period of Earth's history, the Pleistocene, which is still occurring today
Astronomical Cycles
the three cycles of Earth's orbit/rotation which serve as the primary driver for the glacial cycles over periods of hundreds of thousands of years. The three cycles are axial tilt, eccentricity of orbit, and the wobble [precession] of the rotational axis.
Energy Flux
the total amount of energy passing through an area in a given amount of time. The solar energy flux experienced perpendicular to Earth's atmosphere is 1370 Watts per m2.
Habitable Zone
the zone in which liquid water can exist on a planet. It is the distance from the planet's star which is not cold enough for all water to be ice, and not hot enough for all water to be vapor. See also exoplanet.
Glacial Event
this is a time period in which glaciers advance during a glacial period. Often referred to as an "ice age." There can be many glacial events within a glacial period. The opposite is an "interglacial" event. The most recent glacial event ended 11,700 years ago.
Equilibrium Response
this refers to predicted responses to climate changes after systems have come into equilibrium. In terms of biomes shifting in response to a changing climate, we discussed two equilibrium conditions which must occur: first, the climate must come into equilibrium, meaning temperature and precipitation patterns must fully respond to the extra CO2, which could take ~100 years. Second, the vegetation must also come into equilibrium with these new temperature and precipitation patterns, which would take a few hundred more years.
Business-As-Usual
this refers to the future climate scenario in which humans continue to emit increasing amounts of greenhouse gasses, with the amounts following the current trajectory. That is, each year we will emit more than the previous year
Glacial Period
time periods with permanent ice sheets on Earth. There are 5 major glacial periods in Earth's history, including the most recent Pleistocene, which we are still currently in. See also glacial event, which is different.
aerosols
tiny atmospheric particles which can have a warming or cooling effect on the Earth's climate. The overall net effect is a cooling effect, largely via blocking sunlight.
Forcing Factor
variables which have a driving influence on Earth's climate and which can be used as input variables into climate models (e.g. GCMs). See also, forcing process.
Cosmic Ray
very high energy (frequency) radiation traveling through space, originating beyond the Solar System.
Epidemic
widespread occurrence of an infectious disease in a population at a particular time
Calcium Carbonate
an important carbon compound found in shells of plankton, corals, and sedimentary rock such as limestone. Chemical composition: CaCO3
Diatoms
an important type of phytoplankton; measuring the isotopes in their shells is an important tool for reconstructing paleoclimates.
CEO
Chief Executive Officer of a company
Co-generation
an industrial process in which energy is produced while simultaneously capturing the waste heat produced by that energy production, and reusing it as an additional energy source.
Blackbody
an object which emits and absorbs radiation with 100% efficiency. Key physical laws apply to these, which we can use to estimate energy balances for objects which are not true these (e.g. Earth).
Aquifer
an underground reservoir of groundwater
GWP
Gross World Product—the sum of all countries' gross domestic product (GDP)
Angle of Incidence
the angle at which the Sun's energy hits Earth's surface. As the angle decreases from 90° (directly overhead), the Sun's energy flux is spread over a larger area on Earth's surface.
GCM
General Circulation Model. Or, sometimes also referred to as Global Climate Models or Global Change Models. These are dynamic models of Earth's climate represented by interacting components of the Earth system. They are computer simulations built by structuring the Earth into a 3D system of interacting grid cells. Each cell represents a component of the Earth system, such as atmosphere, forest, surface ocean water, etc. Physics principles are then used to simulate how those cells will interact in response to changing inputs (e.g. a perturbation like GHG emissions) and produce certain climate characteristics. Two major types of these are equilibrium models and transient models
GDP
Gross Domestic Product. The total value of all goods and services produced by a country in a year. It serves as one measure of the size of a nation's economy.
Anasazi
Native Americans living in the American Southwest who were forced to abandon their cliff dwelling settlements due to a drought that began in 1270 AD.
Coral Reef
an ecological community found in tropical oceans with warm and shallow water. Coral are slow-growing and immobile animals which provide habitat for a wide variety of other organisms. Coral reefs are therefore environments with very high biodiversity.
Exoplanet
a planet beyond Earth's Solar System. We are mainly interested in whether or not they exist in their star's habitable zone.
Biological Pump
a process by which CO2is moved from the atmosphere into the ocean via phytoplankton photosynthesizing, zooplankton consuming phytoplankton, and dead organic matter becoming buried into ocean sediments.
Coupling
a relationship between systems components in which a change in a state of one component results in a change in a state of another component.
Blue-green algae
The cyanobacteria were formerly known as ____________________.
Frostline
The distance from the Sun where it was cool enough for lighter elements to condense and accrete into the outer planets lacking heavy elements.
Deuterium
a stable isotope of hydrogen (written as 2H, or δD) which can be extracted from glacial ice and used as a proxy for temperature. This is similar to how oxygen isotopes in glacial ice and marine sediments are used as temperature proxies.
Catalyst
a substance which increases the rate of a chemical reaction
Feedback System
a system in which components are circularly linked such that each component acts as both an independent and dependent variable.
Coral Bleaching
The process by which photosynthetic algae living within the symbiotic host coral die, resulting in the white color of the coral being revealed as the colorful algae are lost. Coral bleaching is caused by number of stressors, including rapidly cooling waters, or sustained water temperatures above a threshold. See also "symbiosis".
Carbon Cycle
The recycling (i.e. movement and transformation) of carbon between various reservoirs in the Earth system. There are three general parts of the global carbon cycle: short-term terrestrial, short-term marine, and long-term.
Deforestation
The removal of living biomass by cutting or burning forests. The 2nd largest source of anthropogenic carbon emissions.
2xCO2
This refers to the scenario in which humans will have doubled the concentration of CO2 in the atmosphere compared to pre-industrial levels. In 1700 AD atmospheric CO2 concentration was 280 ppm. It recently got as high as 408 ppm. Thus, currently we are almost to 1.5xCO2. Projections vary, but under the "business as usual" scenario, we are predicted to reach 2xCO2 (580 ppm) by about 2060.
Black Carbon
a type of aerosol created by the impartial burning of wood and fossil fuels. It has a net warming effect on the atmosphere. But see also, aerosols.
Curvilinear
a type of graphical relation in which the sign of the relation stays the same, but the size—or magnitude—changes. The Keeling Curve is an example.
Dust Bowl
an extensive drought in the 1930s throughout the American West. The drought combined with poor farming practices contributed to much soil erosion and subsequent dust storms
Equilibrium GCM
a GCM which is run in response to a single change made to the inputs (i.e. a perturbation) until the components of the Earth system reach new stable states.
Electron
a basic unit of an atom, they orbit around the atom's nucleus and has a negligible mass and a negative charge. The number and arrangement of electrons in an atom plays a crucial role in the chemical reactivity of the atom.
Chlorophyll
a biomolecule found in the chloroplasts (organelles found in the cells of plants and algae) of photosynthetic organisms which allows them to absorb energy from sunlight. It is what gives plants their green color.
Greenhouse Gasses
a class of molecules found in Earth's atmosphere which absorb longwave radiation emitted from Earth's surface. There are many types, with the two most common being water vapor (H2O) and carbon dioxide (CO2).
El Nino
a climatic event in which sea surface temperatures in the eastern Pacific Ocean are warmer than normal, due to decreased strength of the trade winds which would otherwise mix the ocean layers and bring cooler water to the surface. These years tend to produce warmer than average global temperatures. La Nino events are essentially the opposite.
Biome
a community of plants with similar characteristics, such as the type of plant (e.g. tree vs. shrub vs. grass), height, and spacing. The particular biome occurring at a location depends largely on that location's climate
Forcing Process
a component operating independently of other components in the system. See also, forcing factor:
Energy Audit
a comprehensive investigation of a home's or industry's energy use, identifying the most cost-effective ways to reduce energy consumption. Energy audits often result in net savings, meaning the cost of the performing the audit is offset by the money saved by implementing the energy-saving changes.
Drought
a condition experienced when a location's moisture supply is less than climatically expected for a period of 3 or more months. See also "moisture supply".
Department of Defense
a department of the executive branch of the U.S. federal government which coordinates all functions of the Armed Services
Fuel cell
a device which converts the chemical energy of a fuel into electric energy via chemical reactions. They are similar to a battery, but require a constant source of fuel. Often, hydrogen is used as the fuel source, which reacts with a chemical catalyst and oxygen to create water and energy
Emissions Scenario
a future level of greenhouse gas emissions expected to be made by human activity. We emphasize what the IPCC refers to as the "business-as-usual" scenario, in which emissions continue to increase through the 21st century, and the "optimistic" scenario, in which humans rapidly transition to alternative energies not relying on fossil fuels.
Geothermal Heat
heat energy generated in Earth's core—due to initial energy leftover from Earth's creation and the decay of radioactive elements—and radiated toward the surface via conductive action through the crust and concentrated release at hydrothermal vents.
Dropstone
large stones deposited in unconsolidated, sorted fine-grained sediments in lakes or oceans as a result of glacial activity.
Deep-Sea Vent
location at the bottom of the ocean where water gets injected into deep cracks due to the extreme pressure, gets heated by volcanic activity, absorbs minerals from the rocks, and then is shot back out of the vent. Because of the combination of heat and minerals, these are the likely locations that life first evolved as hyper-thermophilic bacteria. They generally exist around oceanic spreading zones such as the mid-Atlantic Ride. ".
Carbonate pump
process by which carbon is transferred from the atmosphere into the ocean water via the formation of carbonate rocks. See also: biological pump
Chemosynthetic
production of food sources (carbohydrates) via chemical energy. It is similar to photosynthesis except that it uses chemical energy instead of light energy. The chemical energy is often from hydrogen sulfide released near deep-sea vents. Hyper-thermophilic bacteria are this. So are methanogenic bacteria.
Banded Iron Formations (BIFs)
ocean deposits from 2.7 to 1.9 BYA consisting of alternating layers of oxidized iron (the red bands) and silicates. They are indicative of oxygen conditions in Earth's early atmosphere.
Archaea
one of the three major domains of life on Earth, based on genetic analyses. These are all single-celled organisms, including methanogenic bacteria and some hyper-thermophilic bacteria
Bacteria
one of the three major domains of life on Earth, based on genetic analyses. These are all single-celled organisms, including some hyper thermophilic bacteria, and cyanobacteria—the first organisms to undergo photosynthesis.
Eucarya
one of the three major domains of life on Earth, based on genetic analyses. These are organisms which have a cell nucleus. They contain all multi-cellular life, although most are single-celled.
Consumers
organisms which feed on producers for their food source continental shelves: shallow areas along the coasts of continents which are typically very biologically productive. They serve as a source of nutrients to the ocean when sea level falls, exposing the nutrient-rich sediment on the shelf.
Coriolis Effect
physical process by which winds and ocean currents are deflected to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere, due to the rotation of the Earth.
abatement potential
the amount of CO2 which is prevented from being emitted to the atmosphere due to the adoption of some technology or energy-saving mechanism.
Carbonate Rock
rocks containing calcium carbonate (CaCO3), such as limestone. They are an important part of the long-term carbon cycle. Their formation is a cooling process, as CO2 is removed from the atmosphere; their weathering is a warming process, as CO2 is released to the atmosphere.
Foraminifera
single-celled zooplankton. Their shells consist of calcium carbonate (CaCO3) and thus the oxygen isotope ratios in their shells offer key evidence of paleoclimates.
Calibration
technique which creates a statistical relationship between two types of data. For instance, a mathematical model can be developed which relates an indirect measure of temperature (e.g. ice core layers) to a direct (instrumental) measure of temperature (thermometer). If the relationship is strong (i.e. "well calibrated"), then the indirect measure can be used as a proxy to infer real temperature from a time period in which direct instrumental records are not available.
Fossil Fuels
the 3rd largest carbon reservoir on Earth, consisting of compacted remains of organic matter, and the largest source of anthropogenic carbon emissions