Drivers of Climate Change Flashcards
What are the anthropogenic drivers of climate changes?
Greenhouse Gases
Aerosols
Land-Use Changes
How does the concentration of greenhouse gases vary over thousands of years?
With changes in glacial periods. During these glacial and interglacial periods, the concentration of various greenhouse gases changes. This is inferred from Vostok Ice Cores.
Describe the data collected from the Mauna Loa Observatory since the 1950s.
This data represents the changes in CO2 concentration over time which features seasonal variation incurred by vegetation and photosynthesis changes.
Since what event has the concentration of various greenhouse gases started to rise?
Industrial Revolution
What are aerosols?
solid particles usually produced in industry and transportation such as dust and soot.
How do aerosols lead to climate change?
They are hydrophilic meaning they attract water vapour in the atmosphere which assists with cloud formation. They can also enrich the whiteness of clouds which leads to increased albedo.
What is the history of aerosol production?
They were previously heavily produced in N.America and Europe during industrialisation, but are now being produced by the largest emerging industrial economies such as China and India.
What is the predicted future of aerosol production?
A sharp decrease as the extent of their impact is realised.
What are the three ways that land use is changing and significantly causing climate change?
Human Appropriation of the biosphere
Ice melt
Automobile use growth
How is human appropriation of the biosphere leading to climate change?
Removing natural vegetation reduces the ability of the terrestrial carbon cycle as well as the albedo
How is the melting of sea ice leading to climate change?
Reducing the amount of sea ice and snow means that the albedo of the earth will dramatically decrease.
How is automobile growth leading to climate change?
By creating more roads this encourages the use of greenhouse gas and aerosol producing cars as well as increasing the amount of low albedo roads with black tarmac surfaces.
What are the natural drivers of climate change?
Sunspot activity
Milankovitch Cycles
Volcanic Activity
What is sunspot activity?
These are 11 year cycles when the surface of the sun is a lot hotter and thus emits a greater amount of radiation.
How likely are sunspot cycles to be MAIN drivers of changes in climate?
Not very likely - there is little correlation between their cycle and temperature records. However, they must be considered as influences still.
What are milankovitch cycles?
Cycles established by a Serbian scientist that outlines how changes in the earth’s tilt, orbit of the sun and proximity of the earth to the sun influence how much radiation the earth receives.
How long is the cycle of change in the earth’s tilt?
~41,000 years
What values does the earth’s tilt vary between?
21.8 - 24.5 degrees
Explain the relationship between the earth’s tilt changes and the radiation over the poles?
The greater the tilt, the greater the seasonal variation (effect is biggest over the poles)
How long is the cycle of change in earth’s orbit of the sun?
~96,000 years
What shape doe the Earth’s orbit of the sun fluctuate around?
Elliptical
What impact do changes in the earth’s orbit of the sun have on climate?
It affects the perihelion and aphelion which affects the strength of winters and summers
What is the perihelion?
Point when the earth is closest to the sun.
What is the perihelion today approximately, when does it occur, how much insolation is received?
147.1mn KM/ 4th January/ 1400 w m2
What is the aphelion?
Point when the earth is farthest from the sun
What it the aphelion today, when does it occur, how much is insolation is received?
152mn km/5th July/ 1311 w m2
what is the percentage variation between the aphelion and the perihelion?
7%
How long is the cycle for the perihelion and aphelion to return to initial position?
22,000 years
What milankovitch cycle is strongest at the poles and at the equator?
Earths tilt = poles
Distance to sun = equator
How do volcanic eruptions influence the climate?
they release material and gases in to the atmosphere that can affect cloud formation. Very similar to the aerosol effect
What was a notable volcanic eruption that affected climate the following years?
Krakatoa 1883
How strong is the correlation between volcanic eruptions and changes in climate?
Some correlation, it is more of an immediate impact with minor magnitude, otherwise it has little influence.
