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Fragile Environments and climate change - Coggle Diagram
Fragile Environments and climate change
natural causes of climate change
Milankovitch cycles
the changes in the way the earth orbits the sun, e.g. more eliptical orbits or the earth's axis becoming more tilted
solar variation
energy from the sin isn't constant, there's energy output cycles. Sunspots show how active the sun is, with the more sunspots, the more energy that reaches earth, so therefore higher temperatures
volcanism
lower global temps as ash and gases go up into the atmosphere and prevent sunlight reaching the earth's surface, so it is reflected back into space
ocean currents
distribute heat around the earth, and a change in currents lead to periods of warming and cooling around the pacific
human causes of climate change
burning fossil fuels
coal/gas/oil, which release CO2 into the atmosphere when burned
deforestation
trees absorb CO2 (photosynthesis). If they are cut down, there will be increasing levels of CO2
waste and landfill
decomposing waste produces methane
agriculture
agriculture practices lead to a release of nitrogen oxides into the atmosphere
the greenhouse effect
gases in Earth's atmosphere traps the sun's heat, causing less heat to be reflected up into space -> can cause the enhanced greenhouse effect
impacts of climate change
rising sea levels
loss of habitat for arctic animals
water shortages
increased temperatures means depleted water stores (evaporation) which will affect human health
flooding
results in more migration, so there is no one to look after the land
changes to agricultural yields
increased temps means a lack of water, decreasing crop yields. this causes desertification. also food prices increase as there are less crops to sell
extreme weather
e.g. flooding, heatwaves, drought
reduced employment and health and wellbeing challenges
characteristics of deserts
found near tropics of cancer and capricorn
little biodiversity with few species of vegetation and animals there
hot, cold and dry
lack of water
thin, sandy soil
human causes of desertification
increasing population
more food is needed which leads to overgrazing and overcultivation which causes soil erosion
natural increase and migration
more fuel is needed, so more deforestation occurs, leading to soil erosion
natural causes of desertification
heavy rain
soil washed away leading to infertility meaning land becomes unusable
changing rainfall patterns
drought, vegetation death
rising temps
drought means land becomes baked and dry and therefore uncultable
impacts of desertification
soil
little plants -> no nutrient cycles -> decline in soil fertility due to overcultivation/grazing ->soil erosion dispersed by wind
reduced agricultural output
decrease in soil conditions and a decrease in water means a decrease in agricultural productivity so the crops fail and livestock dies
malnutrition + starvation + famine
decrease in agricultural output means food shortages, leading to a bad diet causing starvation which can lead to death
migration
no one is left to look after land, and conflict can also occur due to migration
characteristics of tropical rainforests
very wet - over 2,000mm water annually
warm (28 C)
humid
soil isn't very fertile
biodiverse
the trees, animals and soil have has millions of years to adapt to a set of very special conditions. the soil is almost infertile, removal of vegetation causes the soil to become vulnerable to erosion
causes of deforestation
logging/timber extraction
clear felling is common in the Amazon
HEP
because of large amounts of water flowing through the Amazon river basin, the government encourages HEP for countries with increasing populations
mining
Amazon has large amounts of minerals, The rainforest needs to be cleared to mine
transport
to move mined goods/cattle/crops. Roads bring new settlers who clear areas for farming
settlement
indigenous people: cut wood for fuel, cut timber for home, cleared areas for farming
agriculture
livestock = 80% or deforestation, plantations for crops like soybeans and palm oil and sugar cane for biofuels. Soil won't last as long as agriculture happens
impacts of deforestation
displacement of indigenous people
their homes are destroyed. Resources are taken away
soil erosion
nutrients cycle is broken so erosion occurs. Also a decrease in soil fertility, asp a decrease in the growth of plants
economic development
money is generated from selling goods profits come from large scale farming
climate change
deforestation disrupts the water cycle so there is a decrease in evapotranspiration means a drier climate. Water that cools is no longer present -> warmer climate
loss of biodiversity
habitatts destroyed along with cures for diseases
locations of fragile environments
natural environments have specific characteristics that make them unique. these characteristics are a combination of biotic (vegetation, animals and people)and abiotic factors (atmosphere/climate, water and soil/rocks).
any changes in one of these characteristics can affect all of the others. these are sensitive to and easily abused by humans, making them fragile
we can group natural environments into biomes which share similar characteristics
forests are found along the equator, and deserts are typically found between 20 degrees north and south of the equator
climate change, deforestation and desertification all pose a threat to fragile environments