Climate and Climate Change

Greenhouse gases

Gases that absorb and re-emit infrared radiation, trapping heat and keeping Earth’s surface warm enough to support life.

anthropogenic

human-origin

mitigation strategies

reduce emission strategy

adaptation strategies

adapt to a changed world strategy

Weather

describes the atmospheric condition at a specific place at a specific time, time frame is short in minutes, hours days or weeks

Climate

refers to the average pattern of weather over a longer time period, can refer to different scales and the time frame is longer: months, years, decades or more

budget equation

change in something (in time)= sources - sinks

Conservation of mass

change in mass= mass sources- mass sinks

conservation of energy

change in energy= energy sources- energy sinks

Concentration

the amount of a particular gas in a given volume usually in percent (parts per 100) or ppmv (parts per million)

sources

processes that add a gas to the atmosphere

sinks

processes that removes a gas from the atmosphere

permanent gas

does not vary substantially in space or time

variable gas

concentration varies in space and or in time

Nitrogen

78% of the atmosphere, the most abundant gas in the air we breathe, sources include bacterial denitrification during decay of biological material, volcanoes, very chemically stable. Sinks include lightning, fires or bacteria

Oxygen

21% of the atmosphere, sources are photosynthesis, photolysis and sinks are oxidation, decomposition and respiration

Water in the Atmosphere

in gas phase, it is invisible, variable concentration, the most important Greenhouse Gas

Hydrologic Cycle

sources: evaporation, transpiration sinks: precipitation

Ozone in the Troposphere

produced when nitrogen oxides and volatile organic compounds interact in the presence of sunlight

Ozone in the Statosphere

plays an important role in protecting Earth’s surface from life-damaging ultraviolet radiation. naturally produced in the stratosphere as ultraviolet radiation interacts with molecular oxygen. Ozone is also destroyed via interactions with UV radiation.

Natural source of Ozone in stratosphere

UV radiation from the suns trikes an oxygen molecule and splits into two o atoms

natural sink

UV radiation from the sun strikes an ozone molecule and splits off an O atom. the free O atom strikes the O3 yielding two O2 molecules.

stratospheric ozone hole

when sunlight reacts with certain chemicals and “ozone depleting substances” are produced.

aerosols

particles (not gases!) suspended in air that provide nucleus for cloud droplet formation. they interact with water vapor in the atmosphere to form cloud particles and more cloud particles make clouds “brighter” so they reflect more solar radiation

Force

mass times acceleration

acceleration

change in speed or direction of an object

work

done when a force causes an object to move

energy

the ability to do work

internal (thermal) energy

energy of molecular motion in a substance. total kinetic energy produced by random motions of molecules and atoms. Particles moving faster= more internal energy. particles moving slower= less of internal energy. more particles= more energy

Temperature

measures the average kinetic energy of a molecule in a substance

Heat Capacity

the amount of heat needed to raise a temperature of a substance by 1 C, proportional to mass and depends somewhat on composition.

Specific Heat

amount of heat needed to raise the temperature of 1g of an object by 1C not proportional to mass

Conservation of Energy

Energy cannot be created or destroyed only change forms

First Law of Thermodynamics

change in internal energy = heat added- work done by system

adiabatic

no heat is exchanged with the environment