Fragile environments & climate change
How will changing farming help deal with desertification?
-reducing intensity of farming helps to stop the process of desertification -decreasing the number of cattle grazing an area can reduce trampling and vegetation degradation -crop rotation and leaving land to recover fore periods of time can also help Obviously these strategies are difficult to implement in areas where food is already scarce and populations are high
What should sustainable management of a resource include?
-respecting environment + culture of people -giving people control over their land & lives -using traditional skills + knowledge -using appropriate technology- machines/equipment that are cheap, easy to use and do not harm the environment -generate income for local communities -not transnational companies -protect biodiversity
What are the disadvantages of climate change?
-rising sea levels (leads to flooding, erosion , migration, settlements need to be moved from coast, salt water inundation, wellbeing and health affected) -Changing climate (some places warmer and drier, some places wetter) -Increase in desertification -Changes to ocean currents ( El Niño and La Niña effects) -warmer oceans (increase in tropical storms) -Ice retreats and melts -extreme weather conditions (e.g. tropical storms increase) -Ecosystems and biodiversity change (extinction of species)
How does HEP cause deforestation?
-rivers are damned and huge areas of forest are flooded as a result
How does road building cause deforestation?
-roads built through rainforest to enable minerals , timber , cattle +crops to be moved easily -roads bring in new settlers who clear areas for farming
What are environmental impacts of desertification?
-seasonal rivers and water holes dry up, so organisms which live in the, or rely on them for water may die -Vegetation dies causing animals depending on it for food/shelter to perish or migrate -Increased soil erosion. Eroded material is washed into rivers or water holes resulting in contamination
Define the term desertification.
The term used to describe how once productive land gradually changes into a desert like landscape
process of desertification please look at diagram
Look at diagram
What is the positive feedback loop for human causes of desertification?
Population increase leads to (more fuel wood needed which leads to deforestation which means the soil is left bare) and (more food is needed which leads to over cultivation of land so the soil becomes worn out) Leading to soil erosion and then desertification Agriculture means there is more strain on the soil leading to soil erosion and then desertification As the soil becomes worn out and people can't afford fertilisers this leads to poverty
What are some advantages of climate change?
-increase in tourism due to hotter climates -better shipping and opens routes due to the ice melting -new species found -can farm in new places
How can water conservation help deal with desertification?
-it is hard to conserve water in an area receiving very little water over a period of years -for some areas, there is hope with relatively new but simple technology like water spreading weird. These are simple constructions at either side of a stream that spread water from an existing channel onto the surrounding land
How does mining cause deforestation?
-large areas of rainforest cleared for the open-cast mining of minerals such as iron, gold and copper
Why is it hard to have sustainable management of a resource?
-laws put in place are good but they are often broken and there is nobody there to check that they are followed -restoring+replanting is sustainable but takes long and can stunt economic development -soy & cattle moratorium stops it so less deforestation but its only temporary -Internationals treaties not under control of local people and not followed
What are bottom up projects?
-low environmental impact -lowkey -accessible to local communities
What are some challenges of the great green wall?
-overcoming disadvantages -funding (cost) -people need to look after it -relies on the NGO's -need to get saplings
What are top down projects?
-big expensive , designed by governments. Local people have little influence in decisions made. E.g. large dams, hydroelectric power
What are some causes of deforestation?
-commercial logging/timber extraction (globally 26%) -road building -land for farmers -agriculture (globally 32%) -mining -HEP(hydroelectric power)
How will alternative energy resources help to deal with desertification?
-deforestation to provide fuel wood & charcoal is one of the major causes of desertification in the Sahel. The fuelwood is used to cook food, boil water + clean with -finding alternative energy sources can reduce the pressure to deforest. This could be cooking oil, solar power or wind power
What are the causes of desertification
-drought -population pressure -fuel supply -overgrazing -migration
What are 8 ways of dealing with desertification?
-education -reducing soil erosion -changing farming -alternative energy sources -water conservation -technology -top down projects -Bottom up projects
How does land for farmers cause deforestation?
-allows farmers to grow their own food -wood cut down provides them with fuel -stops overcrowding in other parts of the country
What is sustainable resource use?
- ensuring we manage our resources in a way that future generations will still be able to use the same resources -sustainability is the ability of one generation to hand over to the next at least the same amount of resources it started with
How is loss of biodiversity a consequence of deforestation?
-80% of documented species found in tropical rainforests (some most vulnerable to deforestation) -when homes of species lost, they are often unable to survive in the small fragments of forested land left behind. May go extinct even after small scale deforestation -Biodiversity is an important natural resource, providing us with , many goods and services e.g.food, timber, drugs, medicinal. W/out it humans could die
What are the characteristics of desertification?
-Absence of surface water -Dried up watercourses and ponds -Lowering of the water table -Vegetation becomes degraded or completely lost -Increased soil erosion as bare soil is exposed to wind -Increase in salt content of the soil -Soil becomes less usable -Increasing presence of dry loose sand
What are 2 countries that have fragile environments?
-Australia is unsustainable and fragile because it has a lot of deserts , desertification is spreading . The coral reefs are dying due to sea level rise which is a result of climate change/global warming -Madagascar is sustainable but it has a fragile environment as there is a lot of deforestation , habitat destruction and Agricultural fires
What are some examples of greenhouse gases and how are they produced?
-CO2 (by burning fossil fuels , deforestation and burning of wood) -CFCs(chlorofluorocarbons from fridges, packing materials and air conditioning) -Nitrous Oxides (fossil fuels and fertilisers) -Methane(crops especially rice, dead organic matter e.g. landfill and animal manure) The more gases released the greater the greenhouse effect is , trapping more & more heat in the lower atmosphere as it is too thick to allow heat to escape.
Explain the process of desertification
-Desertification starts with an area of land that may be rich with trees and plants but usually semi-arid areas are at a higher risk -Some natural change or human activity may lead to vegetation being degraded or removed -The lack of vegetation leads to reduced transpiration and bare soil being exposed leading to soil erosion by wind and water -Over time, the land becomes drier and t(e soil becomes less fertile leading to a more desert like landscape
Describe the greenhouse effect?
-Greenhouse gases allow sufficient solar radiation through to warm the earths surface -greenhouse gases absorb outgoing radiation, trapping heat in the atmosphere -radiation is re-emitted from the atmosphere back to the earth -some radiation is reflected back into space
What are 3 possible natural causes of climate change?
-Milankovitch cycles - variations in the earths orbit around the sun -Volcanic activity - ash and aerosols ejected into Earths atmosphere by volcanic eruptions can affect Earths temperatures -Cosmic material - similar impact as volcanic activity e.g. meteorites/ space stuff / cosmic material
What are some areas at risk of desertification and why?
-South-south America along the coast due to it being very hot -Most of North Africa due to its intense heat -South Asia and Australia (some parts already desert) -East coast of North America
What are the social impacts of desertification?
-Subsistence farmers crops fail , livestock dies and this can lead to famine and hunger. -Commercial farms growing cash crops such as cotton lose income, which may cause unemployment -with less food being grown and an increase in demand, food prices increase -increased soil erosion makes the land less fertile creating a long term issue for the farming community -clean water is not available for people to drink , increasing the use of contaminated water + diseases such as cholera -people (usually women +children) travel further to find water, which means children miss school and the carrying of heavy loads can lead to back problems
What are some attempted solutions to deal with desertification in the Sahel?
-encouraging farmers to grow drought-resistant crops -improving knowledge and understanding of droughts across the region by launching the Africa Climate Exchange -Use of drip irrigation systems to reduce water usage -lines of rocks are placed across the land to slow flowing rainwater and encourage the deposition of sediments (rich in nutrients). This is a cost-effective option
What are some advantages of the great green wall?
-fertile land grown -will fight against poverty -growing food security -grows health and well-being for the worlds poorest communities -improving water security, so women + girls don't have to spend hours everyday fetching water -grows green jobs which will grow the economy -will bring wildlife back
What are some impacts of deforestation?
-flooding (eroded soil is deposited in the rivers ;this increases the flood risk) -loss of forests and burning (this increases the CO2 in the atmosphere and reduces O2 levels; this may add to global warming) -leaching (removing the trees leaves the soil bare; rainfall easily washes away the nutrients) -native tribes (they are forced to live in smaller areas causing them to clear patches of land before the land has fully recovered) -loss of plants and animals / biodiversity (clearing the forests destroys the habitat for many plants & animals) -economic development ( deforestation provides jobs and increases the economy when wood is sold)
How does deforestation contribute to climate change?
-forests absorb CO2 (helps lower greenhouse gas levels) -deforestation contributes to build up of greenhouse gases as less greenhouse gases are absorbed -trees release CO2 when cut/burned/removed -these greenhouse gas emissions contribute to global warming creating rising temps, changes weather patterns and increases frequency of extreme weather events
Give reasons for the high biodiversity of the Amazon rainforest
-has lots of species of animals , insects + fauna -it has a specialised climate -nutrient rich soil + warm + lots of water -high levels of solar radiation -large area -complex food webs Deep soil,wet -insects +microorganisms thrive
How will education help deal with desertification?
-help people to learn about little changes and educating them about what they need to do to reduce the impact of desertification so that they can survive in the area that they are living in (sustainable). -need to learn about approapriate technology -simple, effective +inexpensive
Why despite its long history and apparent lush appearance is the rainforest so fragile?
-high proportion of its energy and nutrients are stored above the ground in the biomass and therefore are vulnerable to disturbance -plants have low seed production and dispersal capabilities unless seeds germinate immediately they are eaten/decompose -a decline in bees, orchids or agoutis would have negative consequences for Brazilian nut tree -loss of seed dispersing animals (e.g. monkeys) would trigger a decline in many other species -deforestation clears out biodiversity -takes long time to develop ( highly refined +adapted to its specific vegetative and climatic factors
How does deforestation affect economic development?
-in LICs, deforestation can stimulate economic development through exploiting and selling resources -Brazil, Indonesia, Thailand and the Philippines have all done this -However, the benefits are only short term unless something is done to replace forests -Deforestation can have devastating consequences on local communities e.g. In Brazil poor people are lured from their villages to plantations where they are forced to work under inhumane conditions
What are 9 ways to manage forests more sustainably?
-substitution ( finding alternative sources for the resources being taken from the rainforest. The second form of agro forestry is one example - growing the timber and the fuel on plantations elsewhere and using faster growing trees making better use of savanna areas for livestock grazing is another example) -Afro-forestry ( combining crops and trees either by allowing crops to be grown in carefully controlled areas within the forest or by growing trees on farms outside of the rainforest) -Protection of forests (in some countries areas of forests are conserved and protected as natural parks where no or very little development is allowed dip to take place -Selective logging of those trees that are valuable , leaving the rest untouched -Carefully planned and controlled logging in forests -replanting forested areas that have been felled -restricting the number of logging licences to reduce the amount of forest loss -help-logging for example in Sarawak helicopters are used to remove the logs because less damage is done to the remaining forest -Developing alternative energy supplies ( for example ,use of biogas , solar and wind power reduces the amount of wood needed for fuel)
How will reducing soil erosion help with desertification?
-this can be done by planting trees + perennials (regrow every year) -plating trees reduces and even reverses desertification by: -roots bind together soil and protect from soil erosion by wind -transpiration replenishes the water cycle in the local area -trees intercept rainwater, reducing surface runoff, increasing soil moisture and encouraging water storage
What are some disadvantages of the great green wall?
-trees planted may not be native -humans who are planting may be exploited -may have negative impacts on habitats and people who live there -may disturb wildlife
How does commercial logging cause deforestation?
-valuable trees chopped down as they fall, they damage other trees -clear felling where other trees are also chopped down and chipped for pulp which is more damageable
How does deforestation lead to increased soil erosion?
-without trees to anchor fertile soil, erosion can occur and sweep soil into rivers. Agricultural plants that often replace trees can't hold onto soil -many of these plants such as coffee, cotton, palm oil, soybean and wheat can worsen soil erosion -scientists have estimated 1/3 of worlds arable land has been lost through soil erosion and other types of degradation since 1960 -As fertile soil washes away, agricultural producers move on, clearing more forest and continuing the cycle of soil loss
How will the Great Green Wall combat desertification?
It will provide vegetation that scientists hope the tree belt will counter soil erosion, slow wind speeds, and stop the encroaching desert. It is important that the countries plant drought-resistant native trees that will not further disrupt indigenous environments.
How many countries in the world are under threat of desertification?
110
How much land is lost every year to dertification
12 million hectares
Where is the Sahel?
A narrow belt of land in central Africa that borders the southern edge of the Sahara desert
How much land is affected by soil degradation and desertification?
A third of land
What is an example of a top down project helping with deforestation (case study)
Africa's great green wall -international project aiming to grow an area of 8000km of vegetation across the entire width of Africa. The project has been operating for 1 decade so far and aims to be the largest living structure on the planet , 3 times the size of the Great Barrier Reef
How does agriculture cause deforestation?
Areas of tropical rainforest cleared for plantations growing a single crop such as rubber or coffee -plants + grassland grown, which huge nerds of cattle graze on for a few years before another area is cleared for seeding with grass.
What is the positive feedback loop for the natural causes of desertification?
Climate change Less rainfall Bare soil Increased water flow overland (water flow washes soil away/soil erosion by water)(water drained from soil so soil is dry and blown away more easily and a dust bowl is created / soil erosion by wind) (water table lowered) Few plants grow and little farming possible Desertification
What are glacial and Interglacial periods?
Glacial - cold Interglacial -warmer
How can technology help deal with desertification?
Hi-tech (solarpanels +wind turbines) vs small scale and simple enough to be managed directly on a local level (approapriate technology) e.g.water spreading weirs
Where does desertification usually take place?
In semi-arid land on the edges of existing hot deserts
What are 5 human causes of climate change?
Industry Transport Energy Farming practises Deforestation (farming , industry, urbanisation)
What type of soil is more prone to erosion?
The deeper the soil, the greater the ability of the soil to absorb water through infiltration. However hard baked soils are more prone to being eroded by increased surface run off. Exposed souls and dried soil can also be prone to wind erosion
What is the distribution of the worlds fragile environments?
The global distribution of fragile environments is most influenced by the impact of three processes - desertification, deforestation and climate change. The three are linked because the first two are both the causes and consequences of climate change. Together, they are making environments more fragile.