When you think about ‘human environmental impact concerns’, what comes to mind? Perhaps you imagine a flower pushing hippy chained to a tree. Or, the WWF black and white Panda symbol that flashes before the beginning of every documentary. Maybe you even envision a sad picture of Earth with a thermometer dangling out of its mouth. Whatever comes to mind, you know it is not at all that great. Everybody knows the planet is not in a good position these days and everyone has noticed, the emissions reduction schemes tightening the noose on the general public. However, does anyone really know why? Why is the planet in such a state?

Putting this whole climate change issue into context is not something that is achieved over night, and as the ancient Greeks described: the planet, ‘Gaia’ (Mother Earth) is something of a complex system. Gaia is suffering from what scientists are now calling, the dreaded Anthropocene (age of man). Current statistics show, 7.4 billion human beings inhabit our earth (1) and everything we touch has an equal and opposite reaction.

To put this into further perspective let’s look at a recent paper that was published in 2009 by, Nature entitled: ‘A safe operating space for humanity’ (2). Johan Rockstrom, expresses key ideas for the safeguarding of further environmental change, where the only solution is to prevent further change. What does it mean to ‘prevent’ further change? Rockstrom proposes a framework for the ‘planetary boundaries’ that must not be crossed in order to maintain current state.

The earth has lots of complex systems and according to Rockstrom, there are 9 systems – that if the threshold is crossed, will generate unacceptable environmental change. They are known as: climate change; rate of biodiversity loss (terrestrial and marine); interference with the nitrogen and phosphorus cycles; stratospheric ozone depletion; ocean acidification; global freshwater use; change inland use; chemical pollution; and atmospheric aerosol loading (2). These systems can be thought of as a changing interface, a complex network of interlocking puzzle pieces. So how can we put this puzzle back together?

Our planet is subject to stresses, stresses of which are recent to human history. It’s overrun by well … us. Humans have achieved what no other species are close to being capable of, something the experts like to call ‘niche construction’ (1) we have designed the perfect world for us, it has everything we need; clean water, food and shelter as well as other unnecessary comforts like mobile phones, the internet and televisions. Everything we have done to manipulate our patch has consequences and these 9 systems Rockstrom describes, are part of the earth’s environment. They are complex ‘equilibriums’, which means when they are subject to change, consequences can be severe.

Rockstrom recognises three of these systems as being already over the acceptable threshold. And others are heading the same way. Put briefly, humans have been burning coal and pumping chemicals into the atmosphere for a good two centuries (3) so now the atmosphere is changing, humans are taking carbon out of the ground (fossil fuels) and releasing it as a gas into the atmosphere, that gas is trapping heat in the atmosphere warming up the temperature of Gaia.

These same gases and chemicals are also disrupting the water cycle and changing the climate, as well as seeping back into the land, influencing nutrient cycles and seeping into the oceans, making them acidic and bleaching coral (4). So, that explains all these concepts (nitrogen and phosphorus cycles, ocean acidification, stratospheric ozone depletion, chemical pollution and atmospheric aerosol loading). Now for the others: humans are niche constructors (1), so we manipulate our environment to our liking, during the process to perfect our environment we forgot to consider (all life other than humans), and this explains our last key concept: biodiversity loss.

Biodiversity loss means we are losing animal species faster than they can evolve! We are polluting (land and air) faster than Gaia can recover and we are affecting coral reefs and fish populations faster than they can grow. And humans, as a population, are spreading like wildfire taking too much (100-year-old tree crops) and giving too little (using non-renewable resources).

Scientists are calling this earth stage ‘the Anthropocene’ because never before has one single species impacted their environment in such a way (4). And why do we need these boundaries? Because we are affecting all of these 9 systems to a point that everything is changing for the worse. In fact, Rockstrom proposes, our impact is so severe that if we don’t mediate now Gaia won’t just be out of balance; she’ll probably reach a state of no return. But what can we do? Rockstrom describes that setting a boundary for these 9 systems (as they all influence each other) and three boundaries have already been crossed. They are (climate change; rate of biodiversity loss and the nitrogen cycle) that, it is “essential for the life support properties of the environment for human well being” (2), that no further boundaries are exceeded. Or, the prospects for humanities’ future endeavours will truly hang in the balance.

So now we come back to the first question: ‘When you think about human environmental impact concerns, what do you think?’ Well, by now you’re probably going to think: Chemical pollution and atmospheric pollution, ocean pollution, complex systems which need to be mediated and humans are out of control affecting every environment they touch. But you’ll know, there is a solution, if we mediate what is already reaching the threshold and what is going that way, we can stop impacting Gaia to a point of no return. Rockstrom’s important message preceding this idea? We need to stop what we are doing … before a systems error is eminent.

References

(1) Laland, K., Odling-smee, J. & .Feldman, M. 2001, “Cultural niche construction and human evolution”, Journal of Evolutionary Biology, vol. 14, pp. 22-33.

(2) Rockstrom,J et al (2009). A safe operating space for humanity. Nature, 461,472-475

(3) Meure, C., Etheridge, D., Trudinger, C., Steele, P., Langenfelds, R., vanOmmen, T., Smith, A. & Elkins, J. 2006, “Law Dome Co2, CH4 and N2O ice core records extended to 2000 years BP”, Geophysical Research, vol. 33.

(4) Doney, S.C. and D.S. Schimel, 2007: Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene, Ann. Rev. Environ. Resources, 32, 31-66, doi:10.1146/annurev.energy.32.041706.124700

This article was first published on “Science in Australian Society” and reproduced with permission.