Despite the mass human migration from rural to urban areas, we never lost our dependency on nature. We just forgot to think about it. Our entire urban way of life is built on a foundation of natural resources and sustained by essential ecosystems. Biodiversity – the variety of plants, animals and microorganisms – provides us with clean air and water; produces all of our food; makes the raw materials for our clothing and medicines. At the same time, biodiversity represents the only assortment of life known in the universe. We are compelled, existentially as well as morally, to protect it.
We must re-think the current order rather than remain within it, as our quest for endless economic expansion has overshot Earth’s long-term carrying capacity. In their research, Johan Rockstrom et al. identified nine “planetary boundaries” that we exceed at our peril. Specifically, we are vulnerable to increased global warming from climate change; to depleting the ozone layer that blocks the radiation from the sun; and to loading the atmosphere with aerosols that interfere with climate regimes and monsoon systems. We put ourselves at risk from increasing the acidity of the oceans until marine life collapses; from consuming freshwater reserves until water becomes scarce; and from cutting down our forests until land use changes impoverish topsoil, biodiversity and water flows. We are endangered by our emissions of chemical pollutants; by changing the flows of nitrogen and phosphorus, which are essential for agricultural production; and by the loss of biodiversity.
Knowledge of these boundaries is vital but they have limited use in changing our behaviour. They do not provide solutions. Telling us that there is a boundary we should not cross is often an invitation to get as close to the edge as we think we can go. We are quite capable of dispassionately quantifying these limits, although we are not good judges at living within the boundaries we have identified. We have overstepped our own red lines and have already triggered the tragedy of the mass extinction of species and the chaos of climate change. The research team singled out global warming and the loss of biodiversity as the two core boundaries that are connected to all the rest. Either one could “drive the Earth system into a new state”. Neither can be ignored.
“Loss of biodiversity” is a phrase that sanitises the spectre of mass extinction. It takes millions of years for life to recover from a mass extinction. The overwhelming cause of this loss of life is humankind, wilfully from poaching and blindly from the destruction of habitats, overpopulation and pollution. The most deadly aspect of human activity is the speed of our impact that simply gives other species no time to adapt.
One quarter of all mammals and one third of all amphibians are threatened today with extinction. Every species we wipe out represents an irreversible loss to all future generations. If that was not momentous enough, diversity of plant and animal life plays a pivotal role in maintaining healthy ecosystems, and their absence inevitably endangers our own livelihood.
Climate change plays its part in devastating the web of life. At the same time this web is fundamental to natural solutions for absorbing greenhouse gases, such as photosynthesis by green plants. We cannot reduce biodiversity loss without mitigating climate change, and we cannot mitigate climate change without reducing biodiversity loss. The two are interwoven. Climate change is no more important or profound than mass extinction; it is simply the sense of crisis is greater because we feel the impact in everyday life.
Sadly the average person has not heard of many of the flora and fauna that are endangered, and countless species will probably disappear before scientists even manage to identify them. The known unknown of climate change is more tangible to us than the unknown unknown of losing untold species.
We have at last woken up to climate change, and seen that our beds are burning. We need to feel the same sense of urgency about halting the decimation of life and realising that our future is tied to theirs.
Comments