Lecture 8

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					Lecture 8

Sustainable Development & Ecological Footprint
What is “Ecological Footprint”?

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Ecological Footprint – serves as an analytical tool of sustainability or ecological carrying capacity of an area Act as a global indicator for calculation of our pressure on the environment, which enables comparison of consumption pattern/ behavior between countries Definition Ecological Footprint – measures human impact on nature. It shows how much biologically productive land and water is needed to produce all the resources we consume & to take in all the waste we make It seeks to balance “eco-sufficiency” with “eco-efficiency” & is expressed as “unit area” (hectare) per person for a country/ region/continent/planet earth This footprint is NOT a continuous piece of land. Due to international trade, the land & water areas used by most “global citizen” are scattered all over the Earth Biologically productive land & water

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There are 6 main categories of biologically productive areas: 1. Fossil energy land - land reserved for CO2 absorption 2. Arable land - nearly all of the best arable land (1.35 billion ha) is under cultivation, 10 million ha of which are abandoned annually because of serious degradation. As of to date, there exist <0.25 ha per capita world-wide of such highly productive land 3. Pasture - most of the 3.35 billion ha of pasture (0.6 ha per person) are significantly less productive than arable land. Conservation efficiencies from plant to animal reduce the available biochemical energy to humans by a factor of ten. Expansion of pastures has been a main cause of shrinking forest areas 4. Forests - altogether 3.44 billion ha (0.6 ha per capita world-wide) & most of them occupy less productive land 5. Built-up areas - approximates 0.03 ha per capita world-wide, occupying the most fertile areas of the world, hence representing an irrevocable loss of prime arable land 6. Sea - covers 36.6 billion ha of the planet, or 6 ha per person. Roughly 0.5 ha out of these 6 ha harbour over 95% of the seas’ biological production. This marine production is already harvested to the maximum. The Ecological Benchmark per person The Ecological Benchmark per person 1. Because of this, only 1.7 ha per capita are available for human use. It is the ecological benchmark for comparing people’s footprints. 2. The biological available space will drop to 1 ha per capita once the world population reaches 10 billion. If current growth trends persist, this will happen in about 30 years Current Situation

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The bioproductive space for every person in the world varies with nations & time. Through the industrial economy, human being has become the dominant consumer in most of the Earth’s ecosystems:

– 40% of the net terrestrial photosynthesis (Vitousek et al. 1986) – 25-35% of coastal shelf primary production (Pauly & Christensen 1995) – In particular the so-called “Advanced” countries are running massive unaccounted ecological deficits with the rest of the
planet. Since not all countries can be net importers of carrying capacity, the material standards of the wealthy cannot be extended sustainably to even the present world population using prevailing technology

– Today, humanity as a whole uses over one third more resources & eco-services than what nature can regenerate. In 1992,
this ecological deficit was only one quarter People’s Dependence on Nature 1. Provide basic requirements for life (energy, food, water & air etc.)

– Green plants convert sunlight, carbon dioxide, nutrients & water into plant matter, and all the food chains which support
animal life are based on this plant matter. People’s Dependence on Nature 2. Absorbs waste products & provides life-support services (climate stability & protection from UV radiation) 3. A source of joy & satisfaction Man’s overuse of Nature 1. Loss of forests


– Functions (economic, social & ecological) – Deforestation (history, methods & global trends) – Development strategy
2. Soil erosion and contamination

– Mechanisms – Land Degradation problem (case study of China) – Ecological restoration
3. Fishery depletion

– Hong Kong people’s consumption of coral fish – Import of carrying capacity
4. Loss of species

– Reasons (natural & anthropogenic) – Implications (TRF as an example of endemism)
5. Accumulation of greenhouse gases

– Causes (natural & anthropogenic) – Effects
Living Planet Index (LPI) 1. A measure of the natural wealth of the Earth’s forests, freshwater ecosystems, and oceans & coasts 2. The index fell by 33% during the period 1970 - 1999 (Figure 1) 3. The LPI is the average of 3 indices which monitor the changes over time in:

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Populations of animal species in forest in Freshwater &

in Marine ecosystems 4. In all three ecosystem types, the most severe declines were in the southern or tropical regions of the world 5. Much of the loss of biodiversity in northern temperate ecosystems occurred prior to 1970, especially from the early 19th century onwards, hence not recorded in the LPI Ecological Footprint (EF) 1. A conservative estimate of human pressure on ecosystems

– the biologically productive area required to produce the food & wood people consume, to give room for infrastructure,
and to absorb CO2 emitted from the burning of fossil fuel, which is the primary cause of climate change 2. It is expressed in “area units” & each unit corresponds to 1 hectare of biologically productive space with “world average productivity” 3. It is the sum of all areas (at home and faraway) from which a person/country/ region depends on the supply of resources and the absorption of wastes 4. EF changes in proportion to

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Global population size Average consumption per person &

The resource intensity of the technology used Limitations of Ecological Footprint 1. Insufficient data on some uses of biosphere 2. Assume that the technologies of resource exploitation are the same 3. Conservative estimate which distorts the size of some countries’ footprints, although this will not affect the global result 4. The EF of the world’s population from 1961-1997 5. The EF of the world by regions in 1996 is shown in below. The size of each box is proportional to the footprint of each region; while the height of each box is proportional to the region’s average EF per person and the width is proportional to the population of the region. 6. The EF per person by country in 1996 7. The ecological footprint & ecological deficit of continents & selected countries in 1996 is shown in the following table. The negative values suggest an ecological deficit for the continent or country concerned. Consequently, they need to import their missing ecological capacity (carrying capacity) or deplete their local natural capital stocks. Continents or countries with footprints smaller than their existing biological capacity are living within their respective ecological means. However, the remaining capacity is used for producing export goods rather than keeping it as a reserve The Global Trend • Wealthiest 25% of the world uses 75% of the world’s resources


Global ecological footprint is 2.85in 1996 In 1996, the ecological footprint of the global population was already 30% larger than the Earth’s biological productive capacity • As the world population has increased from 5.7 billion to 6.0 billion since 1996, the global footprint is likely to have increased by about 5% in 2000 The Case of China • China accounts for 7% of the world’s cultivated land, but supports 22% of the total population • Population exerts a great pressure on the land – annually 5 billion tons of soil is eroded, representing a loss of 1m soil cover over the entire country • Supply of adequate & clean drinking water is a growing problem • Environmental/ecological degradation problems arise over the entire country e.g. acid rain, flooding, droughts, air pollution…etc • Population expected to increase 0.9% annually during the 10th Five-Year Plan (2001-2005) • Hong Kong has an ecological footprint of 7.14 compared to the world average 2.85 in 1996 • Hong Kong ranked 13th out of 15 countries and regions • If people in Hong Kong continue to consume natural resources and emit CO2 at the existing rates, we need at least 444 times the existing land area (or 170 times the total area including marine waters) to sustain ourselves • If all people in the world consume at rates similar to Hong Kong people, another 2 planets would be needed What can we do? 1. Partake in the sustainability movement, to balance human consumption & nature’s limited productivity in order to ensure that our communities are sustainable locally, regionally and globally 2. More efficient use of resources (e.g. energy - efficient lamps) 3. Consume less by controlling population growth and decreasing consumption 4. To make our communities more livable and sustainable, we can work towards change at the individual, urban and commercial levels. Individual Level 1. Start composting 2. Use energy-efficient light bulbs, shower heads etc 3. Partake in recreation & tourism that have a low impact on the environment 4. Grow some of our own food 5. Live closer to work 6. Use bicycles & public transport rather than cars 7. Buy items made locally or grown locally rather than far away Urban Level 1. High population density areas preferred to dispersed houses 2. Offer living, working and shopping spaces in integrated neighborhoods 3. Discourage the use of cars (e.g. reduce road & parking space) but encourage use of public transport, bicycles and walking (e.g. bicycle speedways) 4. Planting of trees and greenspaces 5. Establish urban land-trusts to give the community more control over land use 6. Introduce housing construction guidelines which minimize the consumption of resources 7. Comprehensive waste reduction systems which include municipal resource reuse and reduction schemes Commercial Level 1. Use local resources rather than imported ones 2. Regain local control over production & distribution of those resources 3. Secure local needs so that the long term livelihood of a region can be protected without compromising the livelihoods of other people in other regions 4. Charge the true costs for private transportation, pollution and resource use Commercial Level 5. Support community-based volunteer and mutual aid networks 6. Encourage ecologically sound business 7. Tax incentives for encouraging sustainable lifestyles, and tax unsustainable behavior THE END

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