Unit 3- Changing the Land Flashcards
Def land cover
The observed biophysical cover on the Earth’s surface, including natural biophysical features of ice, vegetation, water, bare rock and soil, and additions made by human activity such as agriculture, urban and industrial landscapes
Def land use
Characterized by the arrangements, inputs and activities people undertake in a certain land cover type to produce, change or maintain it.
8 types of land cover
-Cultivated or managed
- Natural and semi-natural vegetation
-Cultivated aquatic or regularly flooded areas
- Natural and semi-natural aquatic land cover or regularly flooded vegetation areas
- Artificial surfaces and associated areas
- Bare areas
-Artificial water bodies, snow and ice
- Natural water bodies, snow and ice
4 natural processes that change land cover
Climate change
Geophysical changes
Plant succession
Fires and pests
Impacts of climate change
-Rising temps by at least 1.5 degrees by the end of century
-Decreased snow and ice cover
-Rising sea levels
-Longer fire seasons
-More extreme weather e.g. droughts, floods, hurricans
-Desertification
-Losses to biodiversity and ag
Def. plant succession
The directional non-seasonal cumulative change in the types of plant species that occupy a given area through time. Involves the processes of colonization, establishment, and extinction which act upon the participating land species.
How do ice ages change land cover?
-More snow and ice
-Drier and cooler conditions> more desert and semi-desert areas
-Lower sea levels
Human activities changing land cover (3)
Population dynamics
Policies
Technologies
Population dynamics key points
-rapid growth in last 300 years
- land surfaces have become areas used for housing, production and recreation
- land cleared of nat vegetation for cropping and grazing
- rural to urban migration
What percentage of people live in urban areas?
50-55%
Technologies key points
- allows for rapid, large-scale chnages to land cover
- e.g. dam building, water diversion schemes
- creation of toxic and non-biodegradable substances
- machinery can clear large amounts of vegetation
- mineral-deficient soils can be made suitable
- hybrid or GMO plants can be made to withstand hostile environments
Policies key points
- economic policies influence market prices, imports, exports, wages and tax levels
- incentives can promote logging and development
- policies can protect existing land cover e.g. against deforest
- allocations and diversions of water
Cryosphere def.
The frozen water part of the Earth system.
6 main categories of glaciers and ice sheets
Sea ice
Land covered by glaciers
Land covered by ice sheets, including ice shelves
Land such as tundra covered by snow every winter
Land underlain by permafrost
Peri-glacial zones on the margins of ice-bound land
Tundra def.
Type of biome where tree growth is hindered by frigid temperatures and short growing seasons
Permafrost def.
Permanently frozen layer on or under Earth’s surface. It consists of soil, gravel or sand usually bound together by ice.
Peri-glacial zones
The periglacial environment is a cold climate, frequently marginal to the glacial environment, and is characteristically subject to intense cycles of freezing and thawing of superficial sediments.
Glacial retreat def.
The rate of ablation exceeds the rate of glacial accumulation
Terminus def
Where glacier ice starts to melt
Ablation def
The process of melting ice on a glacier
Glacier mass balance def.
The gain and loss of ice from the glacier system.
Glacier def
A body of ice formed on land and in motion, confined by terrain, usually valleys
Ice sheet def
Vast masses of ice that bury tracts of land beneath them and which are not confined to valleys.
Last glacial maximum def.
17000 to 21000 years ago, temperatures were 6 degrees cooler, most liquid water was held in ice caps, sea levels were 125m lower and there were land bridges between landmasses. Dry period
Holocene climatic optimum def.
Deglaciation following the LGM, a period between 9000 and 5000 years ago when global were warmer than today, the climate was wetter, sea-levels higher and coasts further inland.
4 Natural processes causing the melting of glaciers and ice sheets
Variations in solar energy
Ocean circulation changes
Volcanic activity
Plate tectonics
Variations in solar energy
Solar energy received by Earth is not constant. Earth is sometimes closer to the Sun and sometimes further away ( according to 3 independent cycles every 26000, 41000 and 100000 years) called the Milankovitch cycles
Ocean circulation changes
Changing ocean currents have an impact on the exchange of heat b/w oceans and atmosphere. Leads to a warming or cooling effect. e.g. ENSO system
Volcanic activity
Short-term impacts. Both warming and cooling can occur. Warming: pollutants settling on ice, decreasing albedo, trapping greenhouse gases in the atmosphere. Cooling: Less heat absorbed from atmosphere as sunlight is blocked.
Plate tectonics
Long-term impacts. Movement of continents change oceanic and atmospheric circulation patterns. Colliding plates can also form volcanoes and mountains e.g. Himalayas
Natural sources of CO2
Life
Ocean absorption and dissolution
Volcanic emissions
Greenland location
Far Northern Hemisphere in the arctic circle. Neighbors Denmark, Iceland, and Canada. geologically part of the North American continent
Greenland Ice sheet
Area of 1.7 million km 2
Reaches 3000m above sea level
11% of world’s freshwater supply
Melting of Greenland Ice Sheet
From 1992 to 2018, the ice sheet has lost 3.8 trillion tonnes of ice. Melting is attributed to the deposition of cryoconite and increased average temperatures.
Location of Greenland
Neighbours to Canada, Denmark and Iceland
Part of the North American Continent
Located between the Atlantic and Arctic Oceans
B/w 60 and 83 degrees north of the equator re. latitude
What is the area of the Greenland Ice sheet?
1.7 million km squared
What is the highest elevation of the Greenland ice sheet?
3000m above sea level
What percentage of world’s freshwater is stored in Greenland ice sheet?
11%
From 1992 to 2018, how much ice was lost from the Greenland ice sheet? How much did average annual surface averagetemps increase by?
3.8 trillion tonnes
2.8 degrees
3 factors accelerating the melting of the Greenland ice sheet
- Surface melting
- Moulins
- Sea ice shelves melting
Surface melting of Greenland Ice sheet
Melting due to warmer temps can reveal dirty (dark) ice which lowers albedo
Impacts of moulin formation on Greenland Ice sheet
Moulins (vertical, roughly circular shafts of ice through which water enters) can lubricate and accelerate flow of glaciers towards coast
Sea ice shelves melting
Warmer oceans melt the underside of sea ice shelves
Positive Economic impacts of melting- Greenland ice sheet
Increase in fishing profits as fish migrate north e.g. cod, mackerel
Minerals are being exposed for mining e.g. zinc, copper, gold
Increase in tourism profits
Glacial sand deposits can be extracted and exported to make a profit
Shorter, more efficient trade routes in the Arctic due to less sea ice
Negative Economic impacts of melting- Greenland ice sheet
Move form hunting to fishing is very expensive as equipment needs to be purchased, infrastructure built, people trained
Expensive and extensive damage to infrastructure due to melting permafrost and glacial melt
Positive social impacts of melting glaciers in Greenland
Greenlanders can buy local produce, fresh fruit and veg
Increase in available farming land/ extension of growing season
Archeological relics being uncovered
More land for ecotourism
Negative social impacts of melting Greenland ice
Decreased hunting opportunities due to thinner ice
Ppl require retraining in jobs
Locals experiencing pollution from mining and heavy industry
Damage to homes from melting permafrost
Positive environmental impacts of melting Greenland ice
Growing season has expanded by 3 weeks
Increased fish yields e.g cod, herring
Nutritious water added to oceans and rivers from melting
Negative environmental impacts of melting Greenland ice
Droughts in 2015, 2016 and wildfires in 2017
Potential for 7 meters of sea level rise
Extreme fluctuations in climate
30 billion tons of ice lost every year
Pollution from mining and heavy industry
Increased fresh, cold water in Atlantic ocean could lead to breakdown of circulation systems.
What is spatial technology
Any technology that considers space, place or location in order to determine an object’s position on the Earth’s surface using latitude, longitude or altitude
3 types of spatial tech
GNSS (Global Navigation Satellite System
GIS (geographic Information System)
Remote sensing
GNSS
24 satellites circle the Earth
Identify an exact location on Earth
System can determine a user’s position, speed, bearing, track, distance, distance to destination
Also called Global Positioning Systems (GPS)
GIS
o Most common spatial technology
o Layers of information on a map which can be turned on or off
o E.g. Google Earth
Remote sensing
o Data collected above the Earth from space or by an aircraft and includes satellite images and aerial photographs
o Passive or active
o Can be used for hazard management, oceans, and the atmosphere, measuring ice melt of glaciers.
o A process of measurement or acquisition of info of some property or some object or phenomena by a recording device that is not in physical contact with the object under study
What is Cryosat 2?
A form of remote sensing used to measure ice loss and melt in Greenland
Satellite measures the distance between the surface of the ice and the satellite
Laser or radar altimetry
Local response to melting ice in Greenland
Ilulissat Hydropower
National response to melting ice in Greenland
Imporving agricultural practice and production in Greenland
Global response to melting ice in greenland
The Paris Agreement
When was Ilulissat Hydropower implemented and by which companies?
Finished in 2013
Tucon (tunnelling)
Istak
ABB
Aims and reasons for Ilulissat Hydropower
To reduce the community’s dependence on fossil fuels, especially diesel (which is expensive and highly polluting)
Increase the use of renewable energy
Use a resource that is already available
Strengths of Ilulissat Hydropower
Renewable energy use increases
Replaces diesel generators
Utilizes a resource they already have (meltwater)
Saves 25000 tonnes of CO2 emissions annually
Generates power for 16000 households
Weaknesses of Ilulissat Hydropower
Very difficult to access, so construction and maintenance is difficult
In case of faults, diesel generators has to be restarted which is costly and inconvenient
The glacier is a world heritage site so there are many rules and regulations
Opportunities for Ilulissat hydropower
Opportunity to expand renewable energy use (currently 70% of energy)
Threats to Illulissat Hydropower
Built on permafrost which could melt and compromise structural integrity
When was the national response to melting ice implemented? Location
Early 2000s onwards
Farming occurs in the South of Greenland
Reasons for the national response to melting ice
Growing season has expanded by 3 weeks
Increased temperatures
More land available
Long transport routes are expensive and impact the freshness of food
Aims of the national response to melting ice
To help Greenland become 50% self-sufficient regarding food, increase food security
Main features of national response
A greater variety of crops e.g. potatoes, turnips, strawberries
Introduce dairy cattle
Increased gastro tourism and food delicacies
Increase national sheep flock size (currently 50000)
Agricultural research
Strengths of national response
More fresh food available for locals
Reduction in GHG emissions from transport
Increased self-sufficiency, greater independence from Denmark
Weaknesses of national response
Droughts and bushfires are becoming more frequent
Transport is difficult due to bc of lack of roads and sea ice
Less rain means less pasture and food for sheep (in 2014 it was reported that sheep were 2-4 pounds lighter than average )
Opportunities for national response
Food security for Greenlanders
Threats to national response
Unpredictable climate so hard to plan crops
Droughts and bushfires
When was the Paris Agreement implemented and by who?
4th Nov 2016
194 countries (UNFCCC) plus the EU
Reasons and aims of the Paris Agreement
Limit global warming to 2 degrees Celsius
Reduce use of fossil fuels
Reduce sea level rise and mitigate effects of climate change
How does the Paris Agreement work?
Regularly monitor collective progress towards goals
Each country has individual targets (Nationally Determined Contributions)
Provide financing to countries to help them mitigate and adapt to climate change
Legally-binding international treaty
Strengths of the Paris Agreement
International collaborative approach
Encourages countries such as Japan, China and the EU to embrace net zero and carbon neutrality goals
Weaknesses of the Paris Agreement
Relies on voluntary compliance
Goals not considered ambitious/ rigorous enough
The agreement does not protect those most vulnerable to climate change e.g Pacific Island States
Opportunities for the Paris Agreement
Targets are regularly reviewed and can bceome more ambitious and rigorous
Threats to the Paris Agreement
Highly influenced by politics, so may face opposition or inaction
