We are a threat to all life on earth

Sloep and Van Dam-Mieras (1995) reveal why the natural environment is so important for all life on Earth. For all organisms, it is the source of energy and raw materials for growth, reproduction and development. And it is the transfer of energy and (re)cycling of matter that keeps the biosphere machinery running. However, they warn that the present day human-induced infringements are large enough to upset the ecosystems, threatening all life on Earth. Finally, they recommend that we humans should examine our infringements, investigate their destructive effects and determine how best to repair them or avoid them in the future. In this post Asitha Jayawardena has bases his discussion around this Sloep and Van Dam-Mieras (1995) article.

(For enhanced readability, the main reference (i.e. Sloep and Van Dam-Mieras, 1995) is usually mentioned at the beginning of a section only. My position is clearly differentiated, usually by way of using ‘I’ or ‘my’.)

Sustain what?

Sustainability, or more precisely human sustainability, is a buzz word today. But sustain what?

Reitan’s (2005: 77) answer to this question is, ‘to sustain successful societies.’ However, he emphasises that, even such an anthropocentric focus leads to a requirement of ecocentric sensitivity at all levels, local to global.

The need for an eco-focus is emphasised by a number of other scholars, too. For example, Glasbergen and Blowers (1995), in Maiteny and Parker (2002: 27), view sustainability as ‘a scientific principle indicating the notion of natural systems enduring over time.’

For Maiteny and Parker (2002: 27), sustainability is ‘ultimately about bio-ecological processes remaining functional and viable and keeping human activities to a level where they continue to be capable of supporting our lives and wellbeing, both locally and globally.’ They further remind us that, for existence, nature does not depend on humans but humans depend on nature, which is their environment. The key word here is the ‘environment.’

‘The system that destroys its environment destroys itself,’ declares the Inevitable Rule (Wilden, 1987: 86, in Maiteny and Parker, 2002). Therefore, Maiteny and Parker (2002) propose that ‘human sustainability is… increasingly dependent on developing cultural worldviews that keep natural/ecological systems in a condition that can continue to support human life….’

These scholars’ point of convergence is that an essential requirement for human sustainability is the existence of a healthy planet. But why is the environment so important for life on Earth?

The natural environment’s importance to life on Earth

Sloep and Van Dam-Mieras (1995) explain in detail why the natural environment is so important for life on Earth.

It is from the environment that the living organisms of all species import the energy and raw material required for growth, development and reproduction.

In almost all ecosystems plants, the most important primary producers, carry out photosynethesis, capturing sunlight and storing it as chemical energy. They absorb nutrients from their environment. When herbivores (i.e. plant-eating animals or organisms) eat these plants possessing chemical energy, matter and energy are transferred ‘one-level up.’ The same happens when predators (i.e. animals of a higher level) eat these herbivores or when predators of even higher levels eat these predators. Therefore, in ecosystems, food webs transfer energy and matter and various organisms play different roles in sustaining these transfers.

Such transfers are possible due to the remarkable similarity in all organisms’ composition and major metabolic pathways. In fact all organisms except plants can potentially use each other as energy and nutrient sources; plants, however, depend on sunlight for energy.

Sloep and Van Dam-Mieras (1995) further reveal two key principles governing the biosphere with respect to the transfer of energy and matter in ecosystems.

Firstly, the energy flow in ecosystems from photosynthetic plants (generally speaking, autotrophs) to non-photosynthetic organisms (generally speaking, heterotrophs) is essentially linear. In each step part of energy is lost to the ecosystem as non-usable heat, limiting the number of transformation steps and thereby the number of levels in a food web.

Secondly, unlike the energy flow, the matter flow in ecosystems is cyclic. For photosynthesis plants need carbon dioxide as well as minerals and sunlight. For the regeneration of carbon dioxide plants, the primary producers, depend on heterotrophs, who exhale carbon dioxide when breathing. Like carbon, many other elements such as nitrogen and sulphur flow in cyclic manner in ecosystems. However, it is photosynthesis, and in the final analysis, solar energy that powers the mineral cycles.

Ecosystems are under threat and so are we

Although it seems that a continued energy supply from the sun together with the cyclical flow of matter can maintain the biosphere machinery running forever, we should not take things for granted, warn Sloep and Van Dam-Mieras (1995). And they explain why.

Since the beginning of life on Earth some 3.5 billion years ago, organisms have evolved and continue to do so today in response to environmental changes. However, the overall picture of materials (re)cycling and linear energy transfer has always remained unchanged. We could therefore safely assume that this slowly evolving system will continue to exist for aeons to come if large scale infringements are not forced upon it, conclude Sloep and Van Dam-Mieras (1995).

However, according to them, the present day infringements are large enough to upset the world’s ecosystems and, worse still, human activity is mainly responsible for these infringements. The rapidity of the human-induced changes is particularly undesirable. For example, the development of modern technology has taken place in a very short period of time when compared with evolutionary time scales – within decades or centuries rather than thousands or millions of years.

Their observations and concerns are shared by a number of other scholars. Roling (2009) warns that human activity is capable of making the collapse of web of life on which both humans and non-human life forms depend for their existence. For Laszlo (1989: 34), in Maiteny and Parker (2002), modern human is ‘a serious threat to the future of humankind’. As Raven (2002) observes, many life-support systems are deteriorating rapidly and visibly.

Elaborating on human-induced large scale infringements, Sloep and Van Dam-Mieras (1995) warn that they can significantly alter the current patterns of energy transfer and materials recycling, posing grave problems to the entire biosphere. And climate change is just one of them!

Turning to a key source of this crisis, Sloep and Van Dam-Mieras (1995: 37) emphasise that, although we humans can mentally afford to step outside the biosphere, we are ‘animals among animals, organisms among organisms.’

Their perception on the place of humans in nature is resonated by several other scholars. For example, Maiteny (1999) stresses that we humans are part and parcel of the ecosphere. Hartmann (2001) observes that the modern stories (myths, beliefs and paradigms) that humans are not an integral part of nature but are separate from it are speeding our own demise. Funtowicz and Ravetz (2002), in Weaver and Jansen (2004: 7), criticise modern science’s model of human-nature relationship based on conquest and control of nature, and highlight a more desirable alternative of ‘respecting ecological limits, …. expecting surprises and adapting to these.’

Finally, Sloep and Van Dam-Mieras (1995) propose that we should closely examine our infringements on the biosphere, investigate their destructive effects and determine how best to repair them or avoid them in the future.

‘No social justice on a dead planet’

I believe that the idea that our existence ultimately depends on the rest of nature because we are part of it is fundamental in any endeavour towards human sustainability. It is true that human sustainability can be and is addressed at a variety of levels (e.g. personal/social/cultural/ecological, local/national/regional/global) and with different foci (e.g. environment/development, economy/ecology). Whatever the level or foci are, the ultimate impact on the global or local ecosystems should be given some degree of consideration in order for an initiative to be truly sustainable.

Chairing the Higher Education group of the London RCE (Regional Centre of Expertise) on Education for Sustainable Development at its launch in June 2009, Dr Jenneth Parker shared a quote that she had come across: ‘No social justice on a dead planet.’ This I think amply illustrates my position.

Reference

FUNTOWICZ, S. and RAVETZ, J. (2002) Post-Normal Science – Environmental Policy under conditions of Complexity. [Online] Available from: http//www.nusap.net. (In Weaver and Jansen, 2004).

GLASBERGEN, P. and BLOWERS, A. (1995) Environmental policy in an international context: perspectives on environmental problems. London: Arnold/ The Open University of the Netherlands. (In Maiteny and Parker, 2002).

HARTMANN, T. (2001) Younger culture stories about how things are In: The last hours of sunlight: waking up to personal and global transformation, pp.118-126. London: Hodder and Stoughton.

LASZLO, E. (1989) The inner limits of mankind. Oxford: Oneworld.

MAITENY, P. (1999) Balance in the ecosphere: a perspective. European Judaism, 32(2), issue 63, pp. 131-138.

MAITENY, P. and PARKER, J. (2002) Unit 6 Study guide: Science and culture in education for sustainability. London: Distance Learning Centre, South Bank University.

REITAN, P.H. (2005) Sustainability science – and what’s needed beyond science. Sustainability: Science, Practice, & Policy, 1(1), pp. 77-80. [Online] Available from: http://ejournal.nbii.org/archives/vol1iss1/communityessay.reitan.pdf [Accessed 16 December 2008].

ROLING, N. (2009) A proper study of mankind… New Scientist, 17 January, pp. 40-41.

SLOEP, P. and VAN DAM-MIERAS, M.C.E. (1995) The environment in the eyes of a natural scientist In: GLASBERGEN, P., and BLOWERS, A. (eds.) Environmental policy in an international context: perspectives on environmental problems. London: Arnold/ The Open University of the Netherlands In: MAITENY, P. and PARKER, J. (eds.) (2002) Unit 6 Reader: Science and culture in education for sustainability. London: Distance Learning Centre, South Bank University.

WEAVER, P.M. and JANSEN, J.L. (2004) Defining and evaluating “science for sustainability”. Paper presented at the International Conference on Sustainability Engineering and Science, Auckland, New Zealand, July. [Online] Available from: http://www.nzsses.auckland.ac.nz/conference/2004/Session5/63%20Weaver.pdf [Accessed 16 December 2008].

WILDEN, A. (1987) The rules are no game: the strategy of communication. London: Routledge and Kegan Paul. (In Maiteny and Parker, 2002).