Planetary boundaries and the equilibrium of our planet
Researchers from the Stockholm Environmental Institute, the Stockholm Resilience Center and the Tjällberg Foundation especially Johan Rockström have developed the Planetary Boundaries concept1.
Planetary Boundary Model (Illustration: Steffen et al. 2015; source: website Stockholm Resilient Center)
The model shows shows the status of nine key indicators, crucial processes and systems regulating the stability and resilience of the earth system. Within these planetary boundaries humanity can safely continue to develop without harming the 'health' of our planet (Safe limits are defined by the green areas in the image above). Research suggests it is crucial that we remain within all boundaries, as even exceeding a single boundary can bring about instability and can lead to nonlinear and abrupt environmental changes in ‘continental or planetary-scale systems’1, shrinking resilience. Barnosky et al (2012)2 show that this has already occurred during our planetary history, and that human behaviour could now result in another crossing of this ‘tipping point’, bringing with it unpredicability never experienced by humanity.
The latest revision of the Planetary Boundary model in January 2015 found already four of the nine boundaries (climate change, loss of biosphere integrity, land-system change, altered biogeochemical cycles) having been crossed as a result of human activity1 (Both red and yellow coloured areas in the illustration represent those indicators we are currently exceeding the limits). Among these are two - climate change as well as biosphere integrity - identified as so called 'core coundaries' whose significant altering would "drive the Earth System into a new state"3.
Rockström and his colleagues chose biodiversity as a key indicator in their model as it plays a pivotal role in ‘providing ecological functions to support biophysical subsystems’, effectively underpinning the resilience of other planetary boundary indicators.
The compelling arguments put forward by Cardinale et al (2012)4 clearly illustrate the impact of biodiversity loss on humanity. What becomes clear from this analysis is that biodiversity has an important regulating function, and that higher biodiversity correlates strongly with provisioning of services. For example; greater plant diversity is associated with greater carbon sequestration and resistance to invasive and exotic plants, increasing diversity of fish leads to greater stability in fisheries yield etc4.
Thus, in addition to its intrinsic value and the fact that biodiversity is extremely important in ecosystem balance and planetary resilience, biodiversity also provides direct services and important resources to humanity4–6. Chivian & Bernstein (2010) comment on the quote by Professor Edward O. Wilson, the eminent Harvard biologist, that ants "....do not need us to survive but we need them to survive"6. They argue that "the same, in fact, could be said about countless other insects, bacteria, fungi, plankton, plants, and other organisms. This fundamental truth, however, is largely lost to many of us. Rather, we tend to act as if we are independent of Nature, that driving thousands of other species to extinction and disrupting the life-giving services they provide will have no effect on us whatsoever"6. It should be remembered that biodiversity, in addition to providing environmental stability is also an important source of health and food security.
Importance of biodiversity for humanity - health and food security
In reference to Chivian & Bernstein (2010)6 Larrea (2012) points out that 'most new medicines have been derived from properties of living organisms'7.
There are some plants that have been of special importance for medicine, Here are some examples:
- Morphine from the Opium Poppy (Papaver somniferum),
- Aspirin from the White Willow Tree (Salix alba vulgaris),
- The anticoagulant coumadin from spoiled sweet clover (Melilotus species).
- Tropical plants such as the Madagascar, or Rosy, Periwinkle (Catharanthus roseus) have yielded vinblastine (which has revolutionized the treatment of Hodgkin’s lymphoma, turning a disease that was once uniformly fatal into one that can now be totally cured in many patients) and vincristine (which has done the same for acute childhood leukemia)”.
Medicines from animals include: the ACE inhibitors (which are among the most effective medicines known for treating high blood pressure) from the Pit Viper (Bothrops jararaca), and AZT (azidothymidine) used in the treatment of HIV-AIDS, patterned after compounds made by the marine sponge Cryptotethya crypta.
Microbes have provided us with nearly all of our antibiotics such as penicillin, as well as the cholesterol lowering statins, and rapamycin (also called sirolimus), which is used to coat arterial stents, so that the cells lining the arteries opened by the stents do not divide and re-clog them6.
Biodiversity will be of crucial importance in our fight against disease in the future: "As infectious agents evolve and new diseases are transmitted from domestic animals, conventional medicines become less effective, resistance to antibiotics increases and new products are required. In this context the potential value of biodiversity from rainforests for medical research, as several researchers state, becomes critical for the future of humankind"7.
Moreover our food security depends on biodiversity. Even though only a small number of species are currently used in agriculture their productivity depends highly on "pollination, the stability of our climate, soil fertility, water supply and genetic diversity of crops"7, which are closely related to biodiversity. Through services like carbon storage and regulation of droughts and floods especially tropical ecosystems are of particular importance7.
Why is biodiversity important?: Gretchen Daily, professor of biological sciences at Stanford University (USA) (Source:website Stockholm Resilience Center)
What is happening to biodiversity and what should be tackled to save it?
”The current and projected rates of biodiversity loss constitute the sixth major extinction event in the history of life on Earth - the first to be driven specifically by the impact of human activities on the planet”8,1.
“The main factor currently driving biodiversity loss is habitat destruction—on land; in streams, rivers, and lakes; and in the oceans. Human activities such as: deforestation; bottom trawling in the oceans; the damming and dredging of streams, rivers, and lakes; and the draining and degradation of wetlands, estuaries, and mangroves are responsible.”6
Deforestation and road building leading to biodiversity loss are often consequences of fossil fuel extraction. This deforestation, but also the burning of fossil fuels, contributes immensely to climate change which again negatively impacts biodiversity. Research from Harvard estimates that 25% of species on land will be extinct by 2050 due to climate change6.
Here we can see how exceeding one boundary affects other dimensions in the model of planetary boundaries. The same occurs for nitrate and phosphorus. Over-harvesting of plant and animal species, species introduction and different kinds of pollution, for example the excessive release of nitrate and phosphates in agriculture also generate powerful negative impacts on biodiversity (Chivian and Bernstein, 2010, p. 9). Care needs to be taken to ensure we have a holistic approach to tackling the issues as addressing just a single aspect has the potential to degrade others. Examples can be seen in mechanisms to maintain carbon storage propagated by carbon markets that can lead to loss in biodiversity if biodiversity itself is not also explicitly addressed4.
Here we aim to collate scientific information and give us the opportunity to learn both about human impacts to nature and nature's impacts on humanity. More importantly it is a space to learn from and generate solutions to these planetary impacts by promoting holistic approaches. Having outlined the importance of biodiversity to our planetary systems and its function in human health and food security as well as the inherent threats it faces, let us think of ways to save and enhance biodiversity. Let us try to save the last biodiversity hotspots and wilderness areas such as the Amazon and the forgotten Chocoán forests from degradadtion and destruction.
The Yasuni ITT initiative is one approach we can learn from and see how it could be adapted and implemented in other areas.
References
[2] Barnosky, A.D. et al. (2012), "Approaching a state shift in Earth’s biosphere", Nature, Vol. 486: 52–58, Abstract available at: http://www.nature.com/nature/journal/v486/n7401/abs/nature11018.html
[3] Steffen, W. et al. (2015), "Planetary Boundaries: Guiding human development on a changing planet", Science, Vol. 347, No. 6223, Abstract available at: http://www.sciencemag.org/content/347/6223/1259855.abstract
[6] Chivian, E. and Bernstein, A. (2010), "How our health depends on Biodiversity", Harvard.
[7] Larrea, C. (2012), "Ecuadors Yasuni-ITT Initiative. A Critical Assessment".