climate change Flashcards
(36 cards)
How do ice cores show climate change?
Ice cores can be extracted by drilling into icesheets. Each year a new layer of ice freezes onto the top of an ice sheet. Examining the gases in each layer of ice can show us what the climate and temperature where like hundreds of years ago. Sometimes there are fossils/sediments that cane give scientists even more information.
How is data from ice cores reliable?
It is cross matched with data from other sources like weather stations which have make it more accurate and reliable. They are also untampered with.
What is the sea ice maximum?
Sea ice maximum is the maximum area in the Arctic covered in ice any year - occurs in winter and reaches maximum in Feburary/March
What is the sea ice minimum?
Occurs in summer where the sea ice melts and reaches its minimum in September - minimum area in the Arctic covered in ice.
How did scientiswts study sea ice posistions?
Using satellite photos.
How is the expansion of ice evidence for climate change?
Areas covered by sea ice decreasing by 13.3% every 10 yrs since 1979
How relaible is sea ice posistioning?
Quite reliable. It is based on accurate photos ā but all the
evidence is relatively recent and only goes back to the 1970s
How does global temperature data tell us about the past?
It uses weather stations all around the work to measure the temperature and track temperature changes. These can then be combined to give a global average.
What does global temperature data tell us about climate change?
It tells us that Earthās temperature is getting warmer. It also shows us that temperature increase is accelerating with 10 of the hottest years on record occurring since 2005.
How reliable is global temperature data?
It is quite reliable. Temperature is measured accurately with modern instruments but this isnāt the case for older records. Equipment in 1900, for example, is not as accurate as today. Also, more measuring stations would make it even more reliable.
How does painting and diaries tell us about the past?
Using diary entries from the past and paintings of past events allows an understanding of past climates. For example, there are paintings of the Thames frozen over from 1683.
How do paintings and diaries tell us abour climate change?
Paintings and diary entries from the āLittle Ice Ageā give us evidence that Earthās temperature is warmer today than in the past.
How reliable is paintings and diaries?
It is useful to gain an understanding of past climates where other evidence like temperature records do not exist. However, it is not very reliable as the evidence is quite subjective (based on one personās interpretation). It also might be depicting one off weather events rather than long term climatic change.
What is a sunspot?
Sunspots are dark spots on the Sunās surface which means that the sun is releasing more energy than usual. Scientists believe that the warmer periods are related to an increase in sun spots eg. Medieval Period.
Describe milankovitch cycles?
The earthās orbit around the sun changes from circular to elliptical and back to circular over a period of 96000 years. When the Earth is closer to the sun, more of the Sunās radiation will reacg the Earth, warming it.
Describe how volcanic eruptions can affect climate?
When volcanoes erupt, they release huge amounts of dust containing ask, sulphur dioxide, Co2 and h2o vapour into the atmosphere. These particles reflect the sunās radiation away from the Earth, cooling it down causing global dimming.
What is the greenhouse effect?
The suns emit short wavelength infared radiation that enters the atmosphere and travels towards the Earthās surface.
The earth absorbs some of the radiation but long wavelength radiation is reflected back into atmoshere.
Greenhouse gases canāt absorb the frequency of radiation emittted by the Sun but they can absorb the longer wavelength reflected radiation.
The gases reradiate this energy.
Temperature at Earthās surface rises enough for life to exist.
what is the enhanced greenhouse effect?
Energy comes from Sun as short wave radiation.
Most energy passes through a layer of naturally occurring greenhouse gases in atmosphere.
Earthās surface is warmed.
Some energy is reflected back out to space as long wave radiation.
Long wave radiation does not pass through greenhouse gases as easily as short wave radiation.
Some energy escapes back out to space.
The thicker layer of greenhouse gases absorb more energy + more is reflected back to Earth - more of sunās energy is trapped.
Increases earthās temperature causing climate change.
How does farming contribute to the increase concentration of greenhouse gases?
The digestive systems of cows produce lots of methane, alongside rice paddies emitting a lot of methane gas. Deforestation to create more space for crops also means there are fewer trees removing carbon dioxide from the atmosphere to use in photosynthesis.
How does transport contribute to the increase concentration of greenhouse gases?
Most modern modes of transport run on fossil fuels which release greenhouse gases when they burn. Increasing car owners in developing countries means more cars are on the roads burning fossil fuels.
How does industry contribute to the increase concentration of greenhouse gases?
Cement production is an example of an industrial process that releases greenhouse gases:
- cement is made from limestone, which contains lots of carbon and so co2 is released when cement is made.
Decay of industrial waste in landfills produce methane.
Explain an effect of climate change on environment ie. sea surface temperature increase.
Rising sea surface temperature are caus9ig bioleaching of sensitive corals - loss of biodiversity. Higher sea surface temperatures would also lead to more tropical storms as they would have more energy - with Hurricane Katrina causing an estimated $ 125bn of damage
Explain an effect of climate change on environment ie. reduction of biodiveristy
The rate at which climate is changing is making rapid adaptation key. Evolution takes place over thousands/millions of year, evolving to a warmer earth cannot happen in 100 yrs. Species that are specially adapted to the habitats that are being destroyed and damaged by climate change are at an increased rate of extinction.
Explain an effect of climate change on environment ie. melting ice
Melting ice causes sea levels to rise, which could flood coastal habitats and move the coastline inwards. This would forever lose the land and associated biodiversity. Most ice is stored in the ice sheets at the Arctic and Antarctica. Changes to the way sea ice changes throughout the year is already affecting survival of animals at both places.