Fragile environments Flashcards
What are the key components of fragile environments?
Non-living parts: rock, soil, climate
Living parts: plants, animals
What is the ecological footprint?
Measures how much land and sea are required to provide us with the water, food and energy we need to support our lifestyles. It measures the impact of humans on the natural world.
Which factors influence a country’s ecological footprint?
-Rate of population growth
-Level of consumption of resources per person
-Type of technology used
What is considered a sustainable and unsustainable footprint? What is the global average?
Sustainable footprints: 3,9 and below.
Unsustainable footprints: 4,0 and above.
Global average: 2,85.
What is desertification?
Once-productive land gradually changing into desert-like land. This process isn’t necessarily irreversible.
Name some areas at risk for desertification.
Sahel region, central Africa
Australia
Parts of northern Argentina, Peru and Bolivia
What are the natural causes of desertification?
Droughts
Forest fires
Lack of rain
Soil erosion
Harsh climate events
What are the human causes of desertification?
Overgrazing
Deforestation
Water erosion
Loss of biodiversity
Poor irrigation practices
Intensive use of agricultural lands
What are the causes of desertification in the amazon rainforest?
Fires and deforestation related to livestock farming are creating an arid zone that can’t sustain vegetation.
What are the causes of desertification in the Sahel region?
Population growth has led to increased logging, illegal farming and land clearing for housing.
What are the causes of desertification in the Western and Southwestern US?
Due to overgrazing and overcultivation. Lack of irrigation, deforestation and increased droughts are degrading the land.
What are the causes of desertification in Northern and Western Australia?
Effects of climate change (increased droughts and forest fires), overfarming
What is deforestation?
The cutting down of trees, mainly to use the land for building on it or creating farmland to feed livestock and produce agricultural products.
Why does deforestation happen?
Because forests are very dependent on rainfall and specific climates. They are also vulnerable to deforestation for farming purposes.
What are the natural causes of deforestation?
Forest fires, droughts and pests
What are the human causes of deforestation?
Agricultural expansion
Wood extraction
Livestock grazing
Urbanisation
Population growth
What are Milankovitch cycles?
The collective effects of changes in the Earth’s movements on its climate over thousands of years. They include:
The earth’s orbit
The angle of the earth axis tilt
Direction that the earth’s axis of rotation is pointed to.
What are some causes of climate change?
Volcanic activity
Cosmic material
Human causes
How does volcanic activity contribute to climate change?
Volcanic gases like sulphur can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, can promote global warming.
How does cosmic material contribute to climate change?
Cosmic rays help the formation of dense clouds in the lower atmosphere. These clouds retain more surface energy, keeping the surrounding air hot and potentially increasing t° on earth.
How are human causes contributing to climate change?
Burning fossil fuels, cutting down forests and farming livestock.
This adds enormous amounts of greenhouse gases to the atmosphere, increasing the greenhouse effect and global warming.
What are the 4 main greenhouse gases?
Carbon dioxide, methane, chlorofluorocarbons, nitrous oxide.
What are the sources of CO2?
Burning fossil fuels, burning fuelwood, deforestation.
What are the sources of methane?
Decay of organic matter - waste in landfill sites, animal manure, large areas of crops.
