Global Issues and Threats Flashcards
What are the world’s biggest environmental problems?
Climate crisis, plastic pollution, air pollution, resource depletion, desertification, waste disposal, biodiversity loss, deforestation
What is forest degradation?
Forest degradation is when the forest ecosystems lose the capacity to provide important resources and ecosystem services to humans and nature.
Why are rainforests being cleared?
- farming: since the population is increasing, the global demand for food is rising. In addition, the rapid develpment of wealth in developing countries results in a further increase in demand of food. Agriculture is industrialised in agro-industrialisation by turning into mass productions. This requires more land for both ranching and animal feed if necessary.
- resources: timber is logged for wood to make furniture like mahogany (red wood); deforestation also occurs to obtain mineral resources like oil and iron ore through mining.
What are the two major types of unsustainable farming in rainforests?
cattle ranching and monocrop plantation
What are the characteristics of the process of rearing livestock in the Amazon?
In commercial cattle ranching, the activity is large-scaled, extensive, pastoral, and commercial. The type of farming is sedentary (repeated use of same land) and low-technology, owned by international companies or MNCs (multi-national coporations). Cattle provide beef and hide (leather) to overseas markets.
What are the economical and ecological impacts of rearing livestock in the Amazon?
Rearing cattle requires a large piece of pastureland. However, as the rainforest land is very cheap, the economic return is much higher due to the high global demand of beef. The business is also encouraged for export, improving the living standard of Brazil. However, as rearing cattle requires large-scale deforestation, a lot of carbon is emitted, both when removing the forests and when rearing the cattle. Cattle also emit greenhouse gases like methane, contributing to air pollution and global warming.
What are the characteristics of plantations in the Amazon?
Farmers only grow one type of crop on the large piece of land, which is called monocropping or monoculture. The crops are for sale and called cash crops, with popular examples being soya and corn. Products are mainly for export due to the high global demand, and are used as food, fodder, or biofuel.
What are the impacts of deforestation on the atmosphere?
Local impact: drier climate
1. less trees, sunlight directly reaches the ground. The increase in surface temperature increases evaporation and causes changes in precipitation cycles.
2. Interception and transpiration decreases; less water is returned to the atmosphere, relative humidity decreases.
3. Without trees as a barrier, dirunal temperatures may increase and the wind speed becomes higher, further resulting in a drier climate.
Regional impact: transboundary air pollution
Global impact: greenhouse gases cause glocal warming, more extreme weather/disasters.
These impacts may affect other spheres as well.
What are the impact of deforestation on the biosphere?
Loss of biodiversity/fragility of ecosystem and food web:
1. Loss of habitat causes wildlife to be more vulnerable to poachers or predators; animals may decline in population. The number of pollinators may also be decreased, decreasing the number of vegetation and food source.
2. The lack of food source like fruits, vegetation or prey threatens the balance of the food web.
3. As ocean temperatures increase due to global warming, coral bleaching worsens, damaging the marine ecosystem.
Loss of culture:
Indigenous tribes may lose their food source as they rely on hunting and gathering. They may become more exposed to diseases.
As they interact with people outside the rainforest, their culture may be lost.
What are the impacts of deforestation on the lithosphere?
- Soil erosion: the soil cohesion reduces as there are no roots to hold them together. Soil becomes more vulnerable to wind/water erosion; the nutritious topsoil layer may be washed away, resulting in less fertile soil unsuitable for vegetation growth.
- Loss of soil moisture: roots help the water infiltrate into the soil. Without roots, water does not infiltrate and the water-holding capacity of soil decreases.
These impacts may lead to increased landslide risk, flood/drought risk, and desertification risk.
What are the impacts of deforestation on the water cycle?
Trees play a critical role in facilitating the functioning of the water cycle, which aids to maintain a balance between the water in the flow and water on land. However, when deforestation takes place, the water balance is destroyed, resulting in changes in the water cycle.
What is groundwater?
It is subsurface water that fills the spaces between sediments and within rocks.
What is surface water?
Any body of water found on the Earth’s surface, including oceans, rivers, streams or lakes.
What is channel storage?
The volume of water that is temporarily stored in a river channel while it flows towards an outlet (e.g. lake or reservoir).
What is soil water?
Water held in soil in the pores between the soil particles.
What are aquifers?
They are rocks that contain significant quantities of water. A spring is a natural flow of water from the earth’s surface (it occurs where the water table occurs at the surface).
What is water table?
The boundary between unsaturated zone and the saturated zone underground.
What is interception?
It is the precipitation that is collected and stored by vegetation.
What is evapotranspiration?
The combined loss of water to the atmosphere through transpiration and evaporation, which is the most important aspect of water loss.
What is surface run-off?
The water that flows over the lands surface (overland flow).
What is evaporation?
The transformation of liquid water from the earth’s surface into water vapour.
What is infiltration?
The process by which water soaks into, or is absorbed by the soil.
What is throughflow?
The water flowing horizontally through the soil in natural pipelines.
What is percolation?
The movement of water through the soil itself, into deeper layers of the soil, as it seeps deeper it reaches ground water.
What is transpiration?
The water loss from vegetation to atmosphere.
What is the relationship between vegetation and the components of the water cycle?
More vegetation increases interception and transpiration. As they intercept water, less water reaches the earth’s surface, causing less surface run-off. Also, plant roots help with infiltration, meaning more vegetation leads to more infiltration. This reduces overland flow and increases groundwater store.
