Climate Change Flashcards
What is climate change
A long-term change in the Earth’s climate, causing it to become either warmer or colder
What is greenhouse effect
The retention of heat in the atmosphere caused by the build up of greenhouse gases (e.g. carbon dioxide [CO2], water vapour [H2O] and methane [CH4])
What is enhanced greenhouse effect
Accelerated warming of the planet caused by burning fossil fuels, which release greenhouse gases (e.g. CO2 and CH4) into the atmosphere, “enhancing” the natural greenhouse effect.
What is anthropogenic warming/ global warming
Global warming caused by human action (i.e. burning fossil fuels).
What is climate emergency
A situation in which urgent action is required to reduce or halt climate change and avoid potentially irreversible environmental damage resulting from it.
What is the Quaternary Period
The most recent geological time period and spans
from 2.588 ± 0.005 million years ago to the present
It is divided into two Epochs: the Pleistocene (2.588 million years ago to 11.7 thousand years ago) and the Holocene (11.7
thousand years ago to today).
Give year unit conversions in the Quaternary Period
Giga annum (Ga) = one billion years (1,000,000,000)
Mega annum (Ma) = one million years (1,000,000)
Kilo annum (ka) = one thousand years (1,000)
What are glacial periods
Colder periods with extensive glaciation (ice cover)
What are interglacial periods
Warmer times, with limited ice cover between glacial periods
What are the global effects of climate change
- Melting of glaciers and ice sheets
- Loss of sea ice cover
- Low lying islands at risk of being flooded
- Rising global sea levels
- Seasonal change in migration patterns of birds
- Unpredictable weather patterns
What natural factors affect the Earth’s climate
Volcanic activity
Changes in the Earth’s orbit
Variations in the heat output from the Sun
What is eccentricity
Change in the Earth’s orbit around the sun
How often does orbit change occur
An 100000 year cycle
What is obliquity
Tilt of the Earth’s axis
What is precession
Wobble on the Earth’s axis
What is insolation
Variations in the output of solar energy from the Sun
Why does the Earth’s climate change
- The tilt of the axis varies between 22.2 degrees and 24.5 degrees. The greater the tilt angle, the more solar energy the pole receives
- The gradual change in the orientation of the Earth’s axis affects the relationship between the tilt and the eccentricity
- Earth encounters more variation in energy and receives from the sun when the Earth’s orbit is elongated than it does when Earth’s orbit is more circular
How long does it take to complete a wobble cycle
A 26000 year cycle
What is the sunspot cycle and how long does it last
The number of sunspots increases from minimum to a maximum and repeats over an 11 year cycle
What is a sunspot in solar activity
A dark patch that appears from time to time on the Sun’s surface
What happens when sunspot activity is kept to a maximum
When sunspot activity is at it’s maximum, incoming solar insolation from the Sun increases, which can increase temperatures on Earth.
Only has a very small impact on Earth’s temperature.
What happens when sunspot activity is kept to a minimum
When sunspot activity is at it’s minimum, incoming solar insolation from the Sun decreases, which can decrease temperatures on Earth.
What do violent volcanic eruptions produce into the atmosphere
Ash, gases and suspended aerosols (liquid), for example sulphur
dioxide, which rapidly transforms into a weak sulphuric acid.
What are the primary impacts of ash
Ash can block out the Sun, as it is suspended in
the atmosphere.
This changes the reflectivity of the Earth
(albedo), reflecting some of the incoming solar insolation back
into space, reducing the Earth’s temperature.
