factors affecting climate change Flashcards
climate
the characteristic pattern of weather conditions within a region, including temperature, wind velocity, precipitation and other features, averaged over a long period of time
what are 6 pieces of evidence that climate is changing?
ice sheet depths are decreasing
ocean levels are rising
oceans are acidifying
average global temperatures have increased by 0.74 degrees Celsius; 1.4 degrees in Ontario
wind patterns have changed over the past 50 years
precipitation patterns have changed over the past 50 years
name 4 types of natural causes of climate change (global warming or cooling)
extraterrestrial
atmospheric factors
land and ocean factors
tectonic (terrestrial) factors
what are 4 extraterrestrial causes of climate change?
changes in solar activity
movement of Earth in space
changes in the Earth’s rotation, orbit, and tilt
latitude
what is changes in solar activity?
the amount of solar radiation fluctuates over time
what contributes to changes in solar activity?
sunspots
what are sunspots?
more radiation is emitted by the sun when the number of sunspots is high
what patterns do sunspots follow?
an 11 year cycle of activity showing variations in solar output of approximately o.1%
what is the movement of Earth in space?
Earth rotates and revolves constantly through space around the sun
what causes seasons?
the Earth’s 23.5 degree tilted axis of rotation
what is change in the Earth’s rotation, orbit, and tilt?
changes in movement or position can affect the intensity of solar radiation on different parts of the planet
what contributes to changes in the Earth’s rotation, orbit, and tilt?
eccentricity
tilt
wobble
what is eccentricity?
orbit in space changes from circular to elliptical over a period of 100 000 years; when more elliptical, the Earth receives more radiation when closest to the sun
what is tilt?
Earth’s tilt varies between 22.1 and 24.5 degrees over a period of 41 000 years; the greater the tilt, the greater the temperature difference between summer and winter
what is wobble?
the Earth “wobbles” slightly as it rotates since it is not a perfect sphere
what is latitude?
sun’s rays hit Earth’s surface at different angles due to the curved shape of Earth; at latitudes north or south of the equator, sun’s rays spread over larger areas compared to equator–> the surface heats up less compared to the equator
what is an atmospheric factor?
greenhouse gases
what is a greenhouse gas?
gases in the atmosphere that absorb thermal energy
this helps the Earth to retain energy so that it does not fly off in space (the greenhouse effect)
what would happen without the greenhouse effect?
life on Earth would not be possible, Earth would be a frozen wasteland
what are 5 examples of greenhouse gases?
carbon dioxide methane nitrous oxide ozone water vapour
what are 5 land and ocean factors?
convection currents ocean currents precipitation patterns heat capacity of water albedo
what are convection currents?
hot air rises, cold air sinks; creates wind patterns
what are ocean currents?
oceans absorb and release energy
winds help to move ocean water
differences in temperature causes giant ocean currents like rivers under the water
what are precipitation patterns?
wind and air masses create jet streams which are high altitude winds; impacts where and when rain falls
what is heat capacity?
the amount of energy required to increase the temperature of a substance one degree Celsius
water absorbs a lot of solar energy before it evaporates and retains heat for a long time
what is albedo?
lighter objects reflect solar energy; darker objects absorb solar energy
ice reflects solar energy so it may explain how ice ages progress faster and faster since more ice means more reflected solar energy
what are 2 tectonic factors?
movement of tectonic plates
volcanic eruptions
what is the movement of tectonic plates?
affects wind and ocean currents; can cause the release of greenhouse gases
what are volcanic eruptions?
releases aerosols (tiny particles) that reflect solar radiation back into space releases significant amounts of greenhouse gases they can cause warming or cooling depending on the interaction of other factors
what is an example of anthropogenic climate change?
anthropogenic
what is anthropogenic?
resulting from human influence: release of greenhouse gases through the burning of fossil fuels; the release of carbon dioxide from storage on land and in the oceans
