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AS Edexcel Geography Unit 1 12th May 2015

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Original post by itsConnor_
Thinking ecological impacts of climate change in the Arctic may come up. So far I've got:
· Marine and land-based food web modifications
· Biome distributional change (i.e. plant, animal, soil)
o Fish = arctic char, animals = spruce beetle, caribou
· Habitat loss (e.g. sea ice loss in Arctic = polar bears)
· Treeline advance northwards means tundra is replaced by boreal forest.

Could someone help expand some of my points? Also what exactly is a biome distributional change and what are examples of marine/land-based food web modifications?

You could talk about the spruce bark beetle for food web modifications because it is a new predator that's come in due to the warming climate.
Taking this exam (resit) because I got a C last year. Haven't done masses of revision, but I'm hoping the A2 syllabus overlaps quite a fair amount (GEO4 and the Philippines & California etc). Doing some last minute revision tonight, does anybody have any areas they think will come up? Ive looked at past papers with my teacher and he thinks El Nino/Nina will come up in some variation, migration, trade blocs, globalisation/glocalisation and consumerism, switching places on/off. Mainly because they appear a lot, or haven't come up in a while. Hopefully this one is easier than last year :biggrin:
Are you ready for the exam? I'm having last minute panic :/
So the last time ecological impacts of climate change in the Arctic came up, the examiner's report talked about UV radiation in regards to phytoplankton, saying "The mainarea of confusion was the impact of the increasing/stronger UV rays on phytoplankton,candidates not being able to distinguish between the impact on freshwater and marinesystems, which is slightly different".


​Could someone explain? Why are there increasing UV rays and how does this affect marine food webs?
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Mist__y
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Can some explain to me the albedo effect
Original post by Mist__y
Can some explain to me the albedo effect

Increasing global temperatures is causing sea ice (with a high albedo[0.5-0.7 and 0.9 for snow]) to melt, exposing more ocean surface with a much lower albedo of around 0.06. This means less solar radiation is re-emitted and causes a positive albedo feedback loop. :smile:
Original post by itsConnor_
So the last time ecological impacts of climate change in the Arctic came up, the examiner's report talked about UV radiation in regards to phytoplankton, saying "The mainarea of confusion was the impact of the increasing/stronger UV rays on phytoplankton,candidates not being able to distinguish between the impact on freshwater and marinesystems, which is slightly different".


​Could someone explain? Why are there increasing UV rays and how does this affect marine food webs?


Increasing UV rays due:
1) a change in orbit every 96,000 years changes the distance between the earth and the sun, causing an increase in UV rays reaching the earth.
2) tilt - changes in the tilt of the earth causes different areas of the world to receive more/less energy from the sun (arctic may receive more)

This therefore delivers too much UV to the oceans, which may negatively impact the population of phytoplankton, if they attempt to live deeper in the ocean, they do not receive enough light to photosynthesise and thus reduce in population. This then impacts other marine species as there is an imbalance. Some species may decline in population, which may then affect mammals such as polar bears.
Original post by grammar12
Increasing UV rays due:
1) a change in orbit every 96,000 years changes the distance between the earth and the sun, causing an increase in UV rays reaching the earth.
2) tilt - changes in the tilt of the earth causes different areas of the world to receive more/less energy from the sun (arctic may receive more)

This therefore delivers too much UV to the oceans, which may negatively impact the population of phytoplankton, if they attempt to live deeper in the ocean, they do not receive enough light to photosynthesise and thus reduce in population. This then impacts other marine species as there is an imbalance. Some species may decline in population, which may then affect mammals such as polar bears.


omg i have not been taught this
Original post by itsConnor_
Increasing global temperatures is causing sea ice (with a high albedo[0.5-0.7 and 0.9 for snow]) to melt, exposing more ocean surface with a much lower albedo of around 0.06. This means less solar radiation is re-emitted and causes a positive albedo feedback loop. :smile:


Also, because water is darker (0.06) it absorbs the radiation, causing global warming and thermal expansion in the oceans :smile:
Albedo is the amount of solar radiation reflected by the Earths surfaces. snow and ice reflect most and dark surfaces reflect least
Oceans are dark surfaces so absorb more energy, this increases the temperatures of the sea levels which causes more ice to be melted. As a result this ice is now a dark surface as it is in the ocean.
This causes a cycle called the positive ice albedo feedback
my case studies are
hazards- Philippines and California
climate- arctic and africa
flooding- bangeledesh
flooding in my local area- London(as i live in london)
globalisation- coco cola, morrisons, barclays, apple, wal-mart
migration- poland to the UK
colonial migration- Caribbean, indians, pakistan
retirement migration- UK to spain
I think that natural causes of climate change could come up
Original post by molly9711
omg i have not been taught this


These are for natural causes for climate change, also applicable are volcanic eruptions (volcanic winter) and meteor impacts (similar to volcanic impacts due to large amounts of material in the atmosphere).

Human causes are greenhouse gas emissions, destruction of co2 sinks (deforestation) etc
Original post by grammar12
Increasing UV rays due:
1) a change in orbit every 96,000 years changes the distance between the earth and the sun, causing an increase in UV rays reaching the earth.
2) tilt - changes in the tilt of the earth causes different areas of the world to receive more/less energy from the sun (arctic may receive more)

This therefore delivers too much UV to the oceans, which may negatively impact the population of phytoplankton, if they attempt to live deeper in the ocean, they do not receive enough light to photosynthesise and thus reduce in population. This then impacts other marine species as there is an imbalance. Some species may decline in population, which may then affect mammals such as polar bears.

So Milankovitch cycles mean there is an increase in UV rays, which impairs photosynthesis and phytoplankton growth rates, leading to phytoplankton dying and therefore a modification of marine food webs? Does this effect land-based food webs?

Many thanks.
Did the exam last year and got an A.
The best advice:
- TIMINGS: keep and eye on the time and plan how long to spend on each question/section - do not go over AT ALL, you will regret it.
- Don't worry too much about specific facts for case studies, to be honest you can make up statistics and facts as long as they sound relatively right, almost every time the examiners have no way to disprove you.

Good luck!
(p.s. it's like 1000000x harder at A2!)
Original post by grammar12
These are for natural causes for climate change, also applicable are volcanic eruptions (volcanic winter) and meteor impacts (similar to volcanic impacts due to large amounts of material in the atmosphere).

Human causes are greenhouse gas emissions, destruction of co2 sinks (deforestation) etc


oh yes i do have notes on this! thanks
Original post by itsConnor_
So Milankovitch cycles mean there is an increase in UV rays, which impairs photosynthesis and phytoplankton growth rates, leading to phytoplankton dying and therefore a modification of marine food webs? Does this effect land-based food webs?

Many thanks.


Yes, its easiest to use the Arctic case study. E.g. seals have reduced food source, polar bears have a reduced food source due to less seals, this then impacts other land based food webs as polar bears hunt other species in fewer numbers causing them to increase in population (or decrease if they consume fish).
What are some specific effects on the ecology of the arctic due to CC




thanks
I'm a bit concerned because I'm retaking and last year the grade boundaries dropped by about 2-5 marks? So the chances are that they won't drop this year or they'll be higher this year. Ugh.
question:
im soo clueless, please help

why has transport become cheaper (shipping, containerization, aircraft) and how has that increased TNC trade?

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