Date post: | 26-Jan-2015 |
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Global interactions
environmental change
A word about the pictures• The pictures on these slides have been taken from various internet
sources. I haven’t asked for permission to use them, but this PowerPoint is for non-commercial educational purposes only and I therefore would like to thank you for your forbearance if you happen to find one of your pictures here.
Agro-industrialization
• Technology + cheaper transport = re-sourcing• Retailers and processors have increased
power• Affects LEDCs’ ability to compete• Modern farming methods impact
environment
Agro-industrialization
• Global farming increasingly intensive
• Subsidies partly to prevent farmers going out of business
• Farmers compete and increase efficiency– Labour saving machinery– Agro-chemicals (also
labour saving)– High yield varieties (HYVs)
Increased Yields
• In the last 50 years– Wheat yield increased
2.6 to 8 tonnes/Ha– Barley Yield increased
2.6 to 5.8 tonnes/Ha– Dairy cows – doubled
production of milk (now 5800 litres per year)
Methods and problems
• Animals reared on production lines– Results in increased
spread of disease• Vegetables sprayed with
pesticides– Apples average 17 times– Lettuce (imported)
average 11.7 times– Chemicals enter the
ecosystem
Environmental problems
• Costs for environmental restoration:• £2.3 billion per year ($4.4 billion, Kr 31 billion)– Cleaning up chemicals– Restoring habitats– Coping with sickness
• £200 million per year for water companies to remove pesticides and nitrates
• Just in the UK
Environmental problems• Air pollution and greenhouse gas
emissions• Costs UK £1.1 billion per year• 10% of UK emissions come from livestock
(methane) and fertilizers (nitrous oxide)• UK farmers have damaged ecosystems:
– 190,000 miles of hedgerow– 97% of meadows– 60% ancient woodland– 50% fall in farmland bird population
• Soil degradation• Increased flood risk (14% in some areas)
Water problems – Kenya, a case study
• Lake Naivasha (Kenya) loss of life and shoreland ecosystems
• Caused by– Pesticide pollution– Water extraction– Migrant worker
deforestation
Lake Naivasha today
Lake Naivasha
• Flower and vegetable growers blamed• Water diverted from rivers (remember the
Aral Sea?)• 12 flower firms remove 25% of river water
(enough for 100,000 small farmers)
Flowers• Supplied to UK and European markets• Flowers are 90% water• Exporting water = virtual water• Water exported from a dry to a wet region!• In direct competition to poor farmers and
pastoralists• Flower companies take both land and water
Virtual water import/export
Links• http://lakenaivasha.org/ (Lake Naivara)• http://www.fao.org/DOCREP/005/Y4383E/y4383e0d.htm (agroindustry
in Peru)• http://www.unescap.org/tid/publication/indpub2325_chap1.pdf
(economic effects of agro industry)• http://www.dpi.nsw.gov.au/agriculture/horticulture/floriculture/industry/
export#The-global-flower-trade (the global flower trade)
• http://www.google.se/imgres?imgurl=http://www.waterfootprint.org/WFP_files/Img/VWF_regionLrg.jpg&imgrefurl=http://www.waterfootprint.org/%3Fpage%3Dfiles/VirtualWaterFlows&usg=__86Wdki0ByJxNOMmRfTUG5Iy4hm4=&h=650&w=1270&sz=526&hl=sv&start=3&zoom=1&um=1&itbs=1&tbnid=9gjCJtzc4pwLbM:&tbnh=77&tbnw=150&prev=/images%3Fq%3Dvirtual%2Bwater%26um%3D1%26hl%3Dsv%26sa%3DX%26tbs%3Disch:1
(global virtual water trade)
Mining
Extraction of raw materials
Mined materials
• Metals (mined as ores)– Iron, copper, gold etc
• Industrial minerals– Lime (calcium oxide),
soda ash (sodium carbonate)
• Construction materials– Sand, gravel
• Energy materials– Coal, oil, gas
Impacts of mining
• Habitat destruction– Opencast mines– Disposal of waste rock– By-products of refining– Smelting
Impacts of mining
• Pollution– Extraction, e.g. mercury– Transport, emissions– Processing, e.g. Slag– Leaching of toxic by-products
• Land forms– Derelict land– Artificial hills– Physical and visual pollution
Increased air travel
• Transport produces 25% of global CO2 emissions
• Aviation accounts for 13% of transport emissions
• = total of between 2 and 3%• Shipping transport accounts for
22%• But aircraft are worse because:
Air transport emissions• Nitrogen oxides from exhausts help create ozone• Jet-trails = more clouds = intensified greenhouse
effect• Night-flights = increased condensation
(temperature difference) = more clouds than day-flights
• 25% of flights are night flights• But contribute 60 – 80% of contrail warming