Environmental Sustainability

What is Environmental Sustainability?

An unofficial definition is "the degree to which our surroundings can be maintained in a certain state or at a proper standard". In this context the environment should be thought of as the whole planet and its atmosphere, rather than just the local surroundings.

From a human perspective the environment ought to be healthy, comfortable, productive and pleasant to live in - I assume many other species would have similar "wishes" if they could express them! Many factors influence this - including pollution, land quality and productivity, climate, bio-diversity and availability of natural resources.

Some of the many examples of unsustainable practices can be seen in the food industry. The demand for increasing company profits, and understandable consumer demand for cheap food, has contributed to loss of wildlife habitat and the increasing use of inorganic fertilizer, pesticides and herbicides. Hence questions are asked such as "where have all the wild birds gone?".

Peacock butterfly

In part mitigation, gardens and public areas could be maintained to provide a better wildlife habitat, at least in border or less used areas. These areas may then become more interesting for us as well as wildlife.

Areas of lawn could be left in rotation - here a butterfly (ringed) is hovering around the mixed clover and cat's ear (yes it is - honestly!)

Ecological Footprint

This is a useful indicator of environmental sustainability - it is the area of land a person needs to provide all their resources and to absorb waste and emissions that they produce (including home, vehicles etc.). Many developed countries have average per person Ecological Footprints that are far too high, which is resulting in degradation of the environment at an alarming rate. This degradation is made even worse by poor countries which understandably want to develop, but are doing so in a non-sustainable way. The table below shows the Ecological Footprint per person (in hectares) for some contrasting countries - source "Redefining Progress" www.rprogress.org (2001).

Country Eco Footprint
per person (ha)
Total Land
Required (ha)
Actual Land
Available (ha)
USA 12.2 33,000,000 14,899,000
UK 6.2 3,646,000 1,053,000
Bangladesh 0.6 724,000 97,000
World Average 2.9 163,809,000 * 125,404,000 *

* According to these figures in 2001 we needed 1.3 earths to support the worlds population in a sustainable way (obviously a value greater than 1 is not sustainable!). Estimate your own Ecological Footprint (opens in new window) [ed. note 5/2016: I see that this is now a subscription service, other free websites may be available].

The Greenhouse Effect

This natural effect causes the earth's average temperature to be about 35C warmer than it would otherwise be, so it's generally a very useful thing! The effect is caused by "greenhouse" gases in the atmosphere absorbing heat which is radiated from the earth, and radiating much of it back - effectively acting as a blanket. The main gases which perform this function are CO2, water vapour, methane, nitrous oxide and CFCs - see summary of green house gases

The concentration of greenhouse gases in the atmosphere has been increasing since the Industrial Revolution, and more rapidly in recent decades. It is generally believed that this is causing the earth's average surface temperature to increase steadily, and is additional to naturally occurring climatic cycles. The projected effects of "enhanced global warming" due to human activity have been extensively reported.

Most species adapt and migrate according to climatic conditions. However, many won't be able to cope with the current rapid increase in mean temperatures because they cannot migrate fast enough towards the Polar regions (and Polar species have nowhere to go). For those that can migrate (e.g. humans) competition for reducing amounts of space and resources in temperate regions is likely to increase.


Cleaner Technologies
Swiss Alp peak

In the case of electricity generation, fossil fuel based generation uses up the world's limited supply of these resources, contributing significantly to the worlds CO2 emissions (around 30% of UK CO2 emissions). Natural gas fired generation is cleaner and produces less CO2, but supply is limited and uncertain. Generating technologies which convert different forms of solar energy into electricity are much more environmentally friendly. These include wind, tide, and photovoltaic cells - and apart from their construction consume no resources and produce no CO2 emissions. Hydro-electric generating systems have the same advantages, but large dam schemes can have serious negative environmental impacts. As for nuclear power ........ I'm not getting into that.

For transport, fuel cell power has been the dream for a long time (or a nightmare for oil company executives). There is no greenhouse gas emission when developing power (only water is emitted), but the environmental cost of manufacturing the units has to be considered. The hydrogen fuel needs to be produced using renewable (solar derived) energy - using fossil fuelled energy for this purpose would render the exercise pointless from an environmental viewpoint. Since hydrogen and oxygen are explosive, safe storage is problematic.

In agriculture technology already exists to control the amount of inorganic fertilizer applied to fields so that just enough for a particular crop is used. Wider usage of such technology should lessen manufacturing impacts and harmful effects of over application of fertilizers. In areas which already have excess nutrients, the establishment of strips of fast growing plants or trees along water courses will absorb some of the excess. The biomass produced can be put to good use, possibly as a type of fuel.

Time Considerations

Clean(er) technologies can take a long time to develop, and thus become economically viable for replacing old polluting technologies. It could be several more decades until fuel cell powered vehicles are the norm, and no replacement for aero engines is on the horizon. However, immediate curbs on environmental degradation and emission of greenhouse gases are required. People in developed countries can begin to improve environmental sustainability immediately if we make modifications to our behaviour.

Rich countries, supported by global initiatives, could assist poor countries to develop in an environmentally sustainable way. This means providing financial assistance and training so that sustainable power generation (for example solar/photovoltaic based), and appropriate industrial and agricultural practices can be encouraged. It is believed that economic development promotes population stabilisation, as evidenced in developed countries - this has the potential of reducing demands on the environment in the long term.