climate change Midterm 1

Positive feedback

A positive feedback loop is a process where a system's output amplifies or accelerates the original change, pushing the system further in that direction rather than bringing it back to balance.

Moraine

Ridge, mound, or accumulation of unsorted rock debris pushed, carried, or left behind a glacier

Oxygen Isotopes

Atoms of oxygen with the same number of protons but different neutrons. This information is found in ice cores and sediments and acts as a proxy for past temperature and climate.

Charles Keeling

Scientist who recorded atmospheric carbon dioxide at Mauna Loa observatory and was later confirmed by Arrhenius’s anthropogenic greenhouse effect idea. He documented the steady rise in carbon dioxide levels.

North Atlantic Deep Water (NADW)

Cold, dense water mass formed in high northern latitudes that flows southward to drive global ocean circulation. Warm surface water moves north and grows saltier due to evaporation, cools and then sinks from convection.

Troposphere

Lowest layer of the atmosphere where all the weather occurs.

Chironomids

Non biting midges that live at the bottom of the lake in tubes and are exposed to water temperature. Taking sediment cores tells us what conditions were like in the past and were used to tell park workers where to stock fish.

Pleistocene

Geological epoch that lasted from 2.58 million to 11,700 years ago. The earth experienced repeated cycles of glacial growth and interglacial warm periods.

Negative feedback

Self regulating process where the output of the system works to counteract or reduce the change in the input, helping to maintain stability. For instance, increased temperatures can contribute to cloud formation which reflects that sun and cools the earth

Last Glacial Maximum

Period 26,500 to 19,000 years ago when global ice sheets and glaciers reached their greatest extent. Water was locked up in the ice, which dropped global temperatures and sea levels.

Electromagnetic spectrum

Full range of electromagnetic radiation with varying levels of frequency, wavelength, and photon energy

Formanifera

Marine organisms with hard shells made of calcium carbonate. Carbon dioxide contributes to the ocean acidification process which is corrosive to their shells.

Uniformitarianism

Observations of natural processes happening in the present are used to explain data and geological records left in the past

Solar irradiance

Intensity of sunlight hitting a given area at a certain time. It is measured in watts per square meter.

Radiative forcing

How much a factor, such as CO2 or aerosol concentration, changes the balance between incoming and outgoing solar radiation. Positive forcings lead to warming, while negative forcings cause cooling.

Albedo

Measure of how much sunlight a surface reflects back to space

Ocean buffering and CO2

Ocean’s ability to absorb and chemically breakdown atmospheric carbon dioxide and buffer against warming. However, a tradeoff of this is that the ocean acidifies.

Adaptive capacity

Ability of a community, group, or society to handle stressors or changes in the face of climate threats

North Atlantic Oscillation

Weather pattern that describes the atmospheric pressure difference between the Icelandic low and Azores high. A positive phase describes a larger pressure difference than normal, while a negative phase describes a small pressure difference.

Stefan-Boltzmann Law

The total amount of energy emitted is a function of temperature. Hot bodies emit more energy than cold bodies