Fragile Environmetns And Climate Change Flashcards
Natural hazards that effect the planet
- fires
- high winds
- volcanic eruptions
- cyclone
- earthquakes
Most influential processes to the planet
- desertification
- deforestation
- climate change
What is desertification
When once-productive land gradually changes into a desert-like landscape
Where does desertification take place
- semi arid land
- edges of existing hot deserts
Characteristics of desertification
- a sense of surface water
- dried up watercourses and ponds
- lowering of the water table
- loss of vegetation
- increased soil erosion
- increased salt content in soil
- soil becoming less useable
- increased amount of dry, loose sand
Natural causes of desertification
- change in rainfall
- soil erosion
- intensity of rainfall
Human causes of desertification
- population growth
- migration
- overgrazing
- over cultivation
- deforestation
Reasons deforestation is taking place
- commercial logging
- road building
- land needed for farming
- agriculture
- mining
- hydroelectric power
Why people allow clearing of trees to take place
- earn money
- land is needed
Changes the amount of radiation the planet receives has caused
- eccentricity in the shape of orbit around the sun
- changing tilt of the axis
- wobbles as the earth spins on its axis
What is the Milankovitch theory
Every 100 000 years the three changes combine in a particular way. This reduces the amount of radiation received by the earth leading to a glacial period
- eccentricity in the shape of orbit around the sun
- changing tilt of the axis
- wobbles as the earth spins on its axis
Natural causes of climate change
- Milankovitch cycle
- volcanic activity
- cosmic materials
What are the main greenhouse gases
- carbon dioxide
- methane
- nitrous oxides
- chlorofluorocarbons
How are each of the greenhouse gases produced
Carbon dioxide - burning of fossil fuels
Methane - decay of organic materials
Nitrous oxides - burning fossil fuels, using artificial fertilizers
Chlorofluorocarbons - gases released by aerosols, fridges, freezers, AC
Things that happen once desertification has started
- soil becomes less fertile
- reduced agricultural output
- malnutrition, famine and starvation
- migration
- conflict
Consequences of deforestation
- flooding
- loss of forests
- leaching
- loss of plants and animals
- native tribes lose land
- loss of biodiversity
- increases greenhouse gas levels
Impacts of climate change
- areas becoming drier
- areas becoming wetter
- more extreme weather
- change distribution of ecosystems
- rising sea levels
- loss of settlement
- loss of jobs
- spread of diseases
- conflict
Ways to deal with desertification
- educate people
- reduce soil erosion
- change farming
- change the source of fuel
- water conservation
What are water-spreading weirs
- stone and cement constructions that extend from one side of a valley to the other
- hold back the flow of a river
- reduces water speed
- stops soil being eroded
What is sustainability
The ability of one generation to hand over to the next at least the same amount of resources it started with
What should sustainable management of any resource do
- respect the environment and cultures of local people
- use traditional skills and knowledge
- give people control of their land and lives
- use appropriate technology
- generate income for local communities
- protect biodiversity
Sustainable management of forests
- protection of forests
- carefully planned and controlled logging in forests
- selective logging
- replanted forest areas
- restricting amount of logging licenses
- heli-logging (reduce damage to other trees)
- alternative energy supplies
- agro-forestry
- substitution
Responses to climate change
- join the effort to reduce emission s
- protect and conserve forests
- identify fragile environments
- identify coastal areas that will be threatened
What is a drought
A long period of abnormally dry weather leads to a severe water storage
