UNIT 3 AOS Landcover change (SAC)

Question 1

Present-day global land cover

Answer 1

10% of land on earth is covered by glaciers and ice sheets representing 3/4 of global freshwater source

Every continent has a glacier except AUS

2 major ice sheets found in Polar region (9% Antartica ice sheets).

Majority of glacier retreating

Question 2

Define LGM and it’s details

Answer 2

Last Glacial Maximum 20,000 years ago

30% of landcover is ice-sheets and glaciers in Nth America, Nth europe antartica etc

7 degrees cooler and lower sea lvl

Question 3

Define HCO and its details

Answer 3

Holocene climatic Optimum 8000 years ago, after glacier ice have melted, vegetation is exposed

Question 4

Give characteristics of glaciers and ice sheets

Answer 4

region must be cold and sufficient to sustain ice at freezing level all year round

Only the toughest plants and animals inhibit this environment
Limited solar radiation

Question 5

Give some general info about Greenland

Answer 5

The world’s largest island

56,000 residents
ice sheet cover is approximately 1.7 million km2
contains 11% of the earth’s freshwater supply

Question 6

Define cryoconite

Answer 6

airborne particles, whose dark colour decreases albedo of ice, increasing melting rate

Question 7

What does cryoconite do

Answer 7

increase the melting rate of ice due to the increased surface deposition of airborne particles.

dust from central asian deserts
volcanic eruption particles
Euporean powerplants and engines

Question 8

Natural melting glaciers and ice sheets

Answer 8

Variation in solar energy

Oceanic circulation changes

Techtonic shifts

Volcanic eruptions

Question 9

Variations in solar energy

Answer 9

Solar energy received is not constant

Question 10

Oceanic circulation changes

Answer 10

changing ocean current impacts the exchange of heat between the atmosphere and the ocean

Question 11

Volcanic activity

Answer 11

Eruption cause gases and dusts to be injected into the atmosphere

Question 12

Plate tectonics

Answer 12

movement of plates change oceanic and atmospheric circulation pattern

Question 13

Human causes of melting glaciers and ice

Answer 13

Alteration of the composition of gases in the atmosphere

Alteration of landscapes

Direct addition of heat to atmosphere

Question 14

Alteration of the composition of gases in the atmosphere

Answer 14

increase in the injection of:
carbon dioxide
Fluorocarbons
Methane
Nitrous oxide

60% of greenhouse gases come from cities yet it’s landcover is only 2%

Question 15

Alteration of landscapes

Answer 15

Landscape changes lead to retention of heat near Earth’s surface

urbanisation changes soil moisture balances

Question 16

Direct addition of heat to atmosphere

Answer 16

Burning of fossil fuels for electricity production (heating/cooling)

Carbon dioxide (288 parts per million) pre- industrial, 2018 concentration is (408ppm) risen by approx 200ppm

Question 17

Environmental impacts

Answer 17

sea level rise – puts costal towns and communities vulnerable to storm surges and rising sea lvl

Agriculural output – impact food supply and security – threaten livelihoods

Freshwater rescources – enlarged lakes and outburst causing lake banks to burst – communities reliant on water have to change

Question 18

Economic impacts

Answer 18

Fishing industry – allow for more opportunites for export — cost too much

Tourism industry – boom in tourism – increased carbon footprint therfore, melt

Question 19

social impacts

Answer 19

Farming – allow greenland to export and sand, rock – impact ecosystem

Question 20

use of geospatial tech (general info)

Answer 20

until late 20th century, glaciers is observed at it’s terminus, color change pattern and by digging ice pits for poles to measure the technical

Question 21

Geosptial tech used?

Answer 21

Satellite collect digital elevation, images, topographical data as info

GPS tracking – map images

GNSS– accurate data of glacial movement and elevation – sensors places permanently in locations

Question 22

Geo spatial tech (example)

Answer 22

ICE-SAT-2 Launched by NASA in 2018 uses altimeter laser tech to measure polar ice height on Antartica and Greenland

It’s optical centre can measure lvls of solar radiation and surface reflectivity to predict ice freezing and melting rate

Question 23

Responses to glacier melting

Answer 23

Create publicity and provide info on how to reduce global warming

discussion on actions and policies on carbon emissions (paris agreement)

Economic solution to put a price on carbon

Advocate renewable energy