Geoecology studies the interaction between human economic activity and the natural environment. Resource use, pollution and global environmental problems concern all of humanity today. Exams often cover the classification of resources, calculating resource endowment, the causes and effects of global problems, and the Aral Sea disaster.
§1. Natural resources and their use
Natural resources are the riches of nature used to meet human needs. By exhaustibility they are classified as:
Exhaustible:
non-renewable — minerals (oil, gas, coal, ores): they form over millions of years and cannot be restored within a human lifetime;
renewable — forests, soils, plant and animal life: with careful use they regenerate, otherwise they may disappear.
Inexhaustible — solar, wind, tidal and wave energy, the Earth's internal heat; water as a whole does not disappear (the water cycle), but fresh water is limited.
Resource endowment (reserve life) is the ratio of reserves to annual extraction — how many years a resource will last:
Reserve life (years) = Reserves : Annual extraction
Resources of the World Ocean: biological (fish, seaweed), mineral (shelf oil and gas, iron-manganese nodules on the sea floor), energy (tidal power stations), and salts dissolved in seawater. Sustainable use of nature: low-waste, resource-saving technology, recycling, a shift to renewable energy, saving water in irrigation.
§2. Global environmental problems
Global warming (the greenhouse effect): burning fuel and cutting forests increase carbon dioxide (CO₂) and methane in the atmosphere → heat radiated from the surface is trapped → the average temperature rises → glaciers melt, sea level rises, droughts and severe storms become more frequent.
Ozone depletion: CFCs (freons used in refrigerators and aerosols) destroy the ozone that shields the Earth from ultraviolet radiation. The largest "ozone hole" is over Antarctica.
Acid rain: sulphur and nitrogen oxides from industry and transport combine with water vapour and damage forests and lakes.
Desertification: overgrazing, deforestation and poor irrigation (especially the Sahel in Africa and Central Asia).
Forest loss, above all tropical forests (Amazonia) — the "lungs of the planet" are shrinking and biodiversity is being lost.
1972 — the Stockholm Conference and the UN Environment Programme (UNEP); 1987 — the Montreal Protocol on the ozone layer; 1992 — the Rio de Janeiro "Earth Summit"; 1997 — the Kyoto Protocol; 2015 — the Paris climate agreement
§3. The Aral Sea disaster
The Aral Sea is an endorheic (closed) lake fed by the Amu Darya and Syr Darya; until the mid-20th century it was one of the largest lakes in the world. Causes (mainly human-made):
From the 1960s irrigated land was sharply expanded for the cotton monoculture.
River water was almost entirely withdrawn for irrigation: very little of the Amu Darya and Syr Darya reached the sea.
Canals (such as the Karakum Canal) were inefficient — much of the water was lost to seepage and evaporation.
Consequences:
The sea level fell by tens of metres, the area shrank several times over and the sea split into separate water bodies; salinity rose sharply, and fishing and the port of Muynak stopped working.
A new desert — the Aralkum — formed on the dried seabed; salt and dust storms from it travel hundreds of kilometres.
The climate became more continental: hotter, drier summers and colder winters.
Public health and drinking-water quality worsened; environmental migration occurred in Karakalpakstan and Khorezm.
Measures: planting saxaul on the dried seabed to fix the sand, water-saving technology (drip irrigation), a dam in Kazakhstan to save the Small Aral; the UN Multi-Partner Human Security Trust Fund for the Aral Sea region (2018); the International Fund for Saving the Aral Sea (IFAS).
§4. Other environmental problems of Uzbekistan and nature protection
Soil salinisation: without enough collector-drainage networks the groundwater rises, and after evaporation salt accumulates on the surface — especially in the lower Amu Darya, Mirzachul and Bukhara.
Water shortage: much of Uzbekistan's water forms in neighbouring countries (transboundary rivers), so water saving and regional co-operation are vital.
Air pollution: Almalyk (non-ferrous metallurgy), Angren (coal, power station), Chirchik (chemicals), Navoi, Fergana — industrial emissions; motor traffic in big cities.
Desertification and pasture degradation (Kyzylkum).
Specially protected natural areas:
Nature reserves (zapovedniks) — all economic activity is banned: Chatkal (1947), Zaamin, Hissar (one of the largest), Nurata, Zarafshan, Surkhan, Kitab (geological), Baday-Tugay (Karakalpakstan, tugai riparian forest).
National parks — protection combined with tourism: Zaamin, Ugam-Chatkal.
The Red Book — a list of rare and endangered plant and animal species (for example, the Bukhara deer and the snow leopard).
Worked example
"A country has 1.8 billion tonnes of coal reserves and extracts 45 million tonnes a year. What is its reserve life?"
Use the same units: 1.8 bn t = 1,800 mn t.
1800 : 45 = 40.
Answer: 40 years. Note: if extraction rises, reserve life falls.
Worked example
"A lake shrank from 60 thousand km² to 12 thousand km². By what percentage did it shrink?"
Reduction: 60 − 12 = 48 thousand km².
Percentage: 48 : 60 · 100 = 80 %.
Answer: by 80%. Trap: if asked "what percentage remains", the answer is 20%.
§5. Sustainable development and renewable energy
Sustainable development is development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs. The definition was given in 1987 in the UN commission report "Our Common Future", and at the 1992 Rio summit it became a guiding principle.
Sustainable development = economic growth + social fairness + environmental protection
In 2015 the UN adopted 17 Sustainable Development Goals (SDGs): ending poverty, clean water, affordable and clean energy, climate action, protecting life on land and in the ocean, and others. The target date is 2030. Renewable energy sources emit almost no greenhouse gases and do not run out:
solar — effective where there are many sunny days (Uzbekistan has roughly 300 sunny days a year);
wind — on sea coasts, open plains and mountain passes;
hydropower — on mountain rivers (in Uzbekistan, the Charvak hydropower station on the Chirchiq);
geothermal — in volcanic regions (Iceland).
They have drawbacks too: solar and wind output depends on the weather, so energy storage (batteries) is needed; the reservoirs of large dams flood valleys. The ecological footprint is the biologically productive area needed to regenerate the resources a person or country consumes and to absorb its waste. It is usually much larger in developed countries.
Worked example
"A country generated 80 billion kWh of electricity in a year: 12 billion kWh at hydropower stations and 4 billion kWh at solar and wind farms (hypothetical figures). What is the share of renewables?"
Renewables in total: 12 + 4 = 16 billion kWh.
Share: 16 : 80 · 100 = 20 %.
The remaining 80 % comes mainly from thermal power stations (gas, coal).
Answer: 20 %.
Check yourself
What type of resource is a forest?
Which main gas strengthens the greenhouse effect, and where does it come from?
Which substances destroy the ozone layer, and which agreement restricted them?
What is the main cause of the Aral Sea drying up?
How does soil salinisation happen?
How does a nature reserve differ from a national park?
How many Sustainable Development Goals did the UN adopt, and in which year?
A country gets 15 billion kWh out of 50 billion kWh from renewables (hypothetical figures). What is their share?
Common mistakes
Explaining the Aral disaster only by climate change (the main cause is withdrawal of water for irrigation).
Calling forests a non-renewable resource (they are renewable but exhaustible).
Treating the ozone hole and the greenhouse effect as the same phenomenon (their causes and effects differ).
Forgetting to convert billions and millions to the same unit when calculating reserve life.
Mixing up the rules for national parks and nature reserves.
Treating hydropower as completely harmless: it emits few greenhouse gases, but its reservoirs flood valleys and change river ecosystems.