geography environmental threats to our planet

what are global consequences to climate change

Countries like Holland bangladesh and the maldives are spending money on protection for coastal erosion and flooding which is an economic consequence.

Global sea temperatures are increasing causing more tropic storms which are socially bad as people lose lives and economically bad due to repairs. Hurricane Katrina 2005 1836 people dead and damage cost over 100bn.

What are regional consequences to climate change

Sahara desert is expanding causing more areas to be deserted leading to less agriculture on on land and farmers lose their jobs and struggle to feed family.

Animals could migrate to the area from africa and asia bring diseases to the uk due to the temp increase.

sahal region in africa are suffering from less rainfall. this has resulted in less foood and more impact on the economy in areas like chad and nigeria. this can lead to less money being made by peole and it can also cause people to suffer from hunger.

What are the national consequences of climate change.

the maldives in the indian ocean known for its stunning beaches and has its main icome from tourists. sea levels rise by 80 percent could mean that island underwater by end of century meaning that the counrty could lose itsm main income.

in 2014 droughts lead to less coffe being produced ecomomic effect

Australia 2009 bush fires killed 171 people

river thames has a flood barrier to protect london fromm a small water rise around 8 million live trhere so if it was to be flooded it would have many environmental and social effects

polar climate zone latitude/ charactoristrics

at the poles 90 degrees n/s of equator

cold air from the polar cell sinks producing high pressure.

dry icy winds. wind speed around 50 mph

temperate climate zone lattitude/charactoristics.

mid lattitutes 50/60 n/s of the equator

2 air cells meet 1 cold from polar and one warm from ferrel

this creates low pressure as cold air from poles meets warm air from the equator along a weather front. brings frequent rainfall in uk.

subtropical cliamte zone latitude/ charactoristics

30 degrees n/s equator

high pressure result of sinking air where hadley and ferrel meet.

this creates a belt of deserts eg the sahara with temps exceeding 40 degrees.

Tropical climate zone lattitude/ charactoristics

At 0 degrees on the equator

an area of low pressure where the hadley cell meets causing high rainfall in areas like malaysia.

how is GAC controlled by the movement of air.

controlled by the movement of air between poles and the equator.

low pressure 0 degrees

warm air rises on equator where low pressure

the air then rises and condenses

at ground level this causes the air moving towards the equator as wind. in the atmosphere the air moves away from the equator and will sink 30 n/s

high pressure 30 degrees

at 30 the cool air that has risen at 0 and sank at 60 creating an area of high pressure

clear skies hot weather little wind

low pressure 60 degrees

warm air travelling north to the uk from the mediterainian meets the air that comes down from the poles which is also warming.

the air then rises and cools and condenses causing precipitation. wind is also forms as air rushes to replace what has risen.

What are trade winds?

where there is low pressure the air rises, this happens at 60 degrees between temperate and polar regions.

this is then replaced by new air creating trade winds

these winds blow over oceans picking up water.

what is the hadley cell

largest cell extends from the equator 30 degrees n/s

winds meet near the equator and the air warms and rises which can cause thunderstorms.

the drier air then flows to 30 degrees before sinking over subtropical areas

What is the ferrel cell

30-60 degrees from the end of the hadley cell to 60n/s

air in this cell joins the sinking air at the end of the hadley cell

travel along the mid regions until it rises at the polar cells at the border of the cold air.

What is the polar cell?

The smallest and weakest cell occurs from the edge of the ferrel cell to 90 degrees at the poles.

the air sinmks at the higher latitudes likew the poles and flows towards the mid latitudes where it meets the ferel cell and rises.

how global circulation of the atmosphere leads to extreme weather.

coldest 90 degrees - (vostok)high above sea level - colder and at south pole.

hotttest 30 degrees north - libya - 40km away from tripoli (desert) under high pressure clear skies (so sun can reach ground)

driest - death valley- 30 n of equator protected by mountain - not much rain due to high pressure. 500mm

wettest - 0 degrees on equator- peurto lopez - 13000 mm of rain once even rained every day for two years. warm air rises rapidly leading to large storm clouds which condense.

windiest - 60 degrees - commonwealth bay antartica - air rising at 60 south so air rushes fromm the north to the south at 240 kmh to replace it.

causes of tropical storm

temp needs to cool quickly enough for tall clouds ton form through condensation.

wind speeds need to change slowly with hieght - wind sheer.

if wind speeds in the upper and lower atmospheres are different storms will be torn.

fuelled by warm ocean water water vapour is rapidly drawn upwards into the low pressure system.

this results in heavy rainfall

the spin of the earthb then causes the storm to go outwards.

how has the frewuency of tropical storms changed over time

climate change leads to an increased temp

increased evap at ocean surface encourages formation of storm.

Climate change will make tropical seaon last longer due to temp

tech has improved for detecting tropical storms so could be down to this aswell.

distribution of tropical storm

they are distributed close to the equator at 30 degrees n/s

huricanes have increased since 1995 due to increased sea temp.

el nino and other monsoons have influenced tropical storms by their tracks and distributions

their hasnt been a significant change in distrinution.

how can increased numbers of tropical storms be linked to climate change

higher temp

increased evap on ocean surface encouraging storm to form.

TS longer due to high temp

what are the physical causes to droughts

regular weather patterns above average dry

el nino bring high pressure to australia and indonesia

intertropical covergence zone is a low pressure belt around the equator where the trade winds meet.

the ictz moves between the tropic of cancer and the tropic of capricorn with seasons because of the earths tilt.

where the trade winds meet there is heavy precip and storms.

some years ictz might not get so far north or south to reach driest areas meaning those are not relieved.

what are the human causews of a drought

deforestation- reducing transpiration and soils ability to hold water

more water needed to grow crops- as global temp increased causing more evap.

dam building - limits the flow of rivers downstream

ecxessive irrigation - excessive arificial watering of land causing rivers to dry up

overfarming - more water and nutrients taken from the soil

overpopulation- too many people living in an area using up all of the water.

distribution of droughts

between tropics of cancer and capricorn

recently occured in australia brazil china and india

happen in places that already have dry climate and low rainfall per year so a time with out rainfall can impact people.

they can also happen in an area of high rainfall like a rainforest when they recieve low rainfall for a period of time.

frequency of droughts

many regions like california experience every year.

nasa predict that world wide temp will lead to higher temp and less rainfall causing more drought

What happen on normal years on the p[acific

trade winds blow towards warm water of western pacific off the coast of australia and indonesia. rising air occurs at this location as the water heats up the atmosphere. trade winds across the surface of the pacific push warm water west from peru to australia.

upwelling of cold water inn eastern pacific - good for fishing.

temp 8degress c higher than peru and sea levels bout 0.5 m higher

what happens in the pacific in el nino years

trade winds weaker stop or even reverse in west pacific

piled up water in australia goes eastwards back along pacific

30cm sea level rise in peru preventing usual cold upwelling.

more warm water at coast of peru leading to rising air and low pressure water becomes 6-8 warmer then east

in australia water becomes cooler and less air rising resulting in high pressure stable dry

how is australia influenced by the el nino

influenced every 5-7yr

change in atmospheric pressure over the pacific

leads tom winds changing direction

causes warmer air to spread through the pacific

ocean temp by peru rise lower pressure causing rainfall

brings high pressure clear sky and potetially drought to austrfalia

social impact of el nino drought

rural population decreased as people left due to lack of water putting more pressure on cities

rural area suicide increased

10000 people employed by the cotton growing industry lost their jobs.

economic impact of droughtd

aggriculture production was severely effected. bny 2007 aggriculture onlyt made up 3.6% of australias gdp which was important for areas in south east.

sheep population halved

90% decline for rice.

loss of food supply and revenue for farmers

food prices increased as more had to be imported.

farmers had to sell cattle as they couldnt affford to feed them

the murray river in the south east saw a decline in vistord and loss o revenue of 70 million

environmental impact of drought

water quality decreased as toxic alagae occured in rivers

dams and lakes had reduced water

Hydroeletric power decreased as there wasnt enough water in the reservoir.

70 percent of red gum trees died this distrupted ecosystems and food chains asm they provided habitat for different insect species.

how have people adapted to the drought

dual plumbing system - allows you to reroute grey water or rainwater back intom your house for flushing clean water was used in the house.

rainwater holding tanks - store water from rain which can be used for washing up or even crops so on dryer days water can still be provided.

efficient irrigation - systems set up on farms to help conserve more water like water pipes rather than spraying all of the water over the field.

multimillion dollar desilation plant built by goverment 2012 outside sydney which used salt water from the ocean and coverts into fresh can be used for drinking although it needs to be used well as its expensive to do.

grey water systems - water could be recycled from showers amd sinks to the garden .

laws were made banning people from washing cars and encouraging people to have showers for less than 4 mins.

these have helped australia reduce their daily water usage by 40 percent.