Elizabeth Kolbertr discusses the Sixth Extinction )
The biodiversity crisis — i.e. the rapid loss of species and the rapid degradation of ecosystems — is probably a greater threat than global climate change to the stability and prosperous future of humankind on Earth.
- professor Carsten Rahbek, Director for the Center for Macroecology, Evolution and Climate, University of Copenhagen.
temperature zones are migrating towards the equator at 5 km/year
- Dennis Meadows, author of Limits to Growth
Biodiversity is humanity’s life-support system, delivering everything from food, to clean water and air, to recreation and tourism, to novel chemicals that drive our advanced civilization. Yet there is an increasingly well-documented global trend in biodiversity loss, triggered by a host of human activities
- Camilo Mora, University of Hawaii
We believe that ongoing loss of biological diversity is diminishing the ability of ecosystems to sustain human societies
- Andrew Gonzalez, associate professor of biology and the Quebec Centre for Biodiversity Science, McGill University
We’ve reached a point where efforts to preserve species and biological diversity might no longer be an act of altruisms
- Diane Srivastava, professor of zoology and the Biodiversity Research Centre at University of British Columbia
As much as the consensus statements by doctors led to public warnings that tobacco use is harmful to your health, this is a consensus statement by experts who agree that loss of Earth’s wild species will be harmful to the world’s ecosystems and may harm society by reducing ecosystem services that are essential to human health and prosperity
- Bradley Cardinale, associate professor at the University of Michigan
There are still tens of millions of unknown wild species out there. More than half of our global pharmaceutical and agricultural sectors exist because of bioprospecting among wild species. So it would make sense for biodiversity to be protected and used sustainably, as a raw material for continued discovery and wealth creation
- Dr Julian Caldecott
Soon, the majority of humanity will live in cities. Underlying this trend is a disturbing truth; humans are becoming more and more alienated from our own natural environment. In fact, it is our insular lifestyle that artificially decouples us from nature and eliminates the vital feedback loop necessary for the kind of stewardship that will result in a sustainable coexistence.
Human beings are a part of the natural ecosystem but our footprint has become so large that we now control or alter 40% of all landmass on the planet (excluding glaciers). Our dominance has dramatically skewed natural ecosystems. Our human activities is increasing species extinction at a rate several orders of magnitude faster than the fossil records; 100 to 1000 times faster than the natural extinction rate.
This is all driven by a current nonsustainable economic paradigm that inherently pits human development against natural systems. Yet, this is a false dichotomy. For without the hidden capital of natural ecosystems, there would be no way human civilizations could even exist. If there were ever a time to recognize the inter-connectedness of all nature, it is now.
Figure 1: Major biomes on the planet
Predicted percentage of ecological landscape being driven toward changes in plant species as a result of projected human-induced climate change by 2100. Image credit: NASA/JPL-Caltech
New major political effort is being made to replace this outdated economic system with a new sustainable governance paradigm that recognizes a much broader definition of into its fundamental constitution. Not surprisingly, it is being led not by developed countries with huge vested interest in continuing the current system, but by the tiny government of Bhutan, a small country with relatively little of the natural resources highly sought after by capitalists and where compassion is an integral part of the society. Recognizing the crucial role a new economic paradigm will play in stopping environmental degradation, it has been rapidly supported by 68 other countries.
The major problem behind biodiversity loss and ecosystem degradation is our outdated economic system which places little or no value uponIn our current economic paradigm, the more humans develop, the greater the harm for all the planets remaining species. But humanity does not live in a vacuum. In fact, our health critically depends on the health of all the other species on the planet. Because of nature’s interdependency, threatening the survival of the planet’s other species is also threatening the survival of our own species. Just as with the case of climate change, our damage is becoming so pronounced that we will soon begin to experience large positive feedback effects. In fact, biodiversity loss and climate change are intimately related. It is well known that the rate of environmental degradation accelerates as species disappear. Species exist in complex inter-relationships which are required to maintain the health of natural ecosystems which support human society in many ways – from water, to CO2 sequestration, to natural resources. , albeit in a very narrow way.
The earth is comprised of a number of major biomes such as ocean, desert, forest, fresh water, etc…Due to the exponential increase in human stressors, many of these biomes are approaching collapse, with dire consequences not just for humanity but all life on earth.
Background – Why is Biodiversity so important to us?
Economy and Ecology both come from the same Greek root, οἴκος which means “house”. It is clear then that in economic activities, humans, like the other species of the planet are simply trying to take care of our home. Yet we have become so disconnected with our true home, the planet that we are in danger of destroying it. We often hear talk of leaving a broken planet to our children but where are the children in all this? Where are the vietnam-like protest movements? They are nowhere to be found. Our children have been raised in homes far away from trees, forests and lakes, indoors surrounded by video games, iphones, tablets and cartoons for babysitters. They are content to be immersed in their video games, little Nero’s doing modern fiddling while modern Rome burns. As environmental writer George Monbiot writes in his piece Housebroken, we have become so alienated and disconnected from the land, the true source of wealth for all human beings that our children are nowhere to be found in this environmental movement.
Figure 1: Humans / environment feedback loop
Figure 2: Severed human / environment feedback loop due to manufacturing
Where once we grew our own food, made our own clothing, built our own homes, now these are all done for us. Manufacturing plants shield us from nature and severe the natural feedback loops that exist when people produce directly for themselves or there communities. Today, citizens of the developed countries go to supermarkets to buy supplies that are manufactured for us in distant plants. We know nothing about what ingredients go into our food or how manufacturers acquire the resources to create the products we consume. Consumerism naturally shields us from knowing what is really happening. The entire retail production and sales chain protects us from the truth because if we knew, we wouldn’t want to support them.
Figure 3: How human economy fundamentally depends upon the planet for ecological services
Biodiversity, Ecosystems, & Ecosystem Services
What is the value of nature?
Biodiversity Loss is becoming a Critical Issue for Human Survival
A variety of global changes are driving rates of species extinction that greatly outpace background rates in the fossil record. If these trends continue, projections suggest that within 240 years Earth may face the sixth mass extinctionA paper released to coincide with Rio +20 addresses the increasing seriousness of biodiversity loss, A global synthesis reveals biodiversity loss as a major driver of ecosystem change, published in Nature, June 7, 2012 by scientist David U. Hooper et al. shows that biodiversity loss will impact human societies in ways far more profound than first thought.
- Hooper DU et al.
“Some people have assumed that biodiversity effects are relatively minor compared to other environmental stressors,” said biologist David Hooper of Western Washington University, the lead author of the paper. However, Hooper says “Our results show that future loss of species has the potential to reduce plant production just as much as global warming and pollution.” Until this study, it had been unclear how biodiversity losses stack up against other human-caused environmental changes that affect ecosystem health and productivity. This analysis now establishes that reduced biodiversity affects ecosystems at levels comparable to those of global warming and air pollution.
Many people take vital things like water purity, food production, a stable climate and air quality for granted, unaware that they are largely provided by communities of organisms. If we lose those communities, we lose these vital functions. The very high rates of modern extinctions–due to habitat loss, overharvesting and other human-caused environmental changes–could reduce nature’s ability to provide these critical goods and services.
Genetic diversity has many other positive benefits to humanity including:
- increasing the yield of commercial crops
- enhancing the production of wood in tree plantations
- improving the production of fodder in grasslands
- increasing the stability of yields in fisheries
- providing the source for novel new drug therapies
Plant diversity also contributes to:
- greater resistance to invasion by exotic plants
- inhibits plant pathogens such as fungal and viral infections
- enhances above-ground carbon sequestration through enhanced biomass
- increases nutrient re-mineralization and soil organic matter
The authors of this paper performed a research review of over 1,000 ecological studies published in 192 peer reviewed journals since the 1992 Rio Summit. They reached two major conclusions:
- there is mounting evidence that extinctions are altering key processes important to the productivity and sustainability of Earth’s ecosystems
- further species loss will accelerate change in ecosystem processes but it is unclear how these effects compare to the direct effects of other forms of environmental change that are both driving diversity loss and altering ecosystem function
The researchers used a suite of meta-analyses of published data to show that the effects of species loss on two important ecosystem processes – productivity and decomposition of dead plants by bacteria and fungi—are of comparable magnitude to the effects of many other global environmental changes.
- Intermediate levels of species loss (21–40%) reduced plant production by 5–10%, comparable to previously documented effects of ultraviolet radiation and climate warming. At intermediate levels, species loss generally had equal or greater effects on decomposition than did elevated CO2 and nitrogen addition
- Higher levels of extinction (41–60%) had effects rivalling those of ozone, acidification, elevated CO2 and nutrient pollution
- The identity of species lost also had a large effect on changes in productivity and decomposition, generating a wide range of plausible outcomes for extinction
As human populations grow in both size and, plants and animals are becoming extinct at a rate not seen in eons. Studies suggest:
- about one-quarter of the earth’s mammal species will be gone in 20 years
- the oceans have lost about 90 per cent of their large fish
- about 17,000 endangered species in the world
Scientists believe that even these figures are a massive underestimate because theys only apply to the known species, which is estimated to be a fraction of the total number of species on the planet.
The study clearly showed that the ecosystem consequences of local species loss are as quantitatively significant as the direct effects of several global change stressors that have mobilized major international concern and remediation efforts.
Biodiversity Loss: Overwhelming Consensus from many scientists
A study entitled Scientists’ opinions on the global status and management of biological diversity published in the Nov, 2011 issue of Conservation Biology (25: 1165-1175) reveals unanimous agreement of major biodiversity loss from a diverse cross-section of scientists. Dr. Murray Rudd from the Environment Department at the University of York surveyed 583 conservation scientists and found:
- 99.5% agreement that a a serious loss of biological diversity is either ‘likely’, ‘very likely’, or ‘virtually certain’
- 72.8 % agreement that loss is ‘very likely’ or ‘virtually certain’ from scientists based in Western Europe
- 90.9% agreement that loss is ‘very likely’ or ‘virtually certain’ from scientists based in Southeast Asia
- 79.1 % of respondents stated that acceleration of the loss of biological diversity by human activities is virtually certain
Conservation Alone is insufficient to protect against Biodiversity Loss
A 2011 study published in Marine Ecology Progress Seriesreveals a surprising result: humanities existing conservation measures are insufficient to stem global biodiversity loss. Camilo Mora and Peter F. Sales, authors of the study Ongoing global biodiversity loss and the need to move beyond protected areas: a review of the technical and practical shortcomings of protected areas on land and sea performed a literature review of existing studies and data and concluded that effectiveness of existing, and the current pace of the establishment of new, protected areas will not be able to overcome current trends of loss of marine and terrestrial biodiversity. Another way the authors put this is:
In short, the extent of coverage by PAs is still limited and is growing at a slower rate than that at which biodiversity threats are developing
- Camilo Mora and Peter F. Sales
Today there are globally over 100,000 protected areas covering 17 million square kilometers of land and 2 million square kilometers of oceans but it is still not enough. The rate of conservation lags too far behind the rate of human encroachment on natural ecosystems.
Figure 5: Mechanism of human effect on biodiversity. Left: Cascade showing the connections between human population, human
needs, effects on biodiversity and conservation measures. Right: Actual temporal trend of the world’s human population (from the
United Nations World Human Population Prospects, http://esa.un.org/unpp/), of the world’s human population
(from Fig. 1b in Kitzes et al. 2008), response index (i.e. combined extent of conservation strategies such as protected area extent
and biodiversity coverage, policy responses to invasive alien species, sustainable forest management and biodiversity-related
aid; from Fig. 2c in Butchart et al. 2010) and trend in the global living planet index as a proxy for biodiversity status
(data from Hails 2008) (Source: Camilo Mora et al.)
Dr. Camilo Mora said: “Given the considerable effort and widespread support for the creation of protected areas over the past 30 years, we were surprised to find so much evidence for their failure to effectively address the global problem of biodiversity loss. Clearly, the biodiversity loss problem has been underestimated and the ability of protected areas to solve this problem overestimated.”
The authors concluded that biodiversity loss is unlikely to be stemmed without directly addressing theof humanity. In particuliar, this study, in combination with previous study shows that under current conditions of human comsumption and conservative scenarios of human population growth, the cummulative use of natural resources of humanity will amount to the productivity of up to 27 Earths by 2050.
Figure 6: Projections for (a) human population size, (b) human
ecological demand and (c) ecological debt under different
scenarios of human population growth and use of natural
resources. Ecological demand is calculated by multiplying the
size of the world’s human population by the average yearly
demands of a person and dividing this amount by the Earth’s
; this yields the number of planet Earths required
to meet the whole human demand. Ecological debt is calculated
as the cumulative ecological demand beyond the Earth’s ;
this is also referred as ‘ ’. We ran a business-as-usual
scenario (black solid lines) considering the United Nations
projections on human population size (http://esa.un.org/unpp/),
the current average annual consumption per person (in terms of
area necessary to meet consumption demands) and Earth’s
(i.e. 2.1 and 11 billion ha in 2002, respectively; Kitzes et al. 2008).
We also show projections under the ‘rapid reduction’ scenario
suggested by Kitzes et al. (2008) (grey solid line obtained directly
from Fig. 3 in Kitzes et al. 2008). In this scenario, the Earth’s
increased by 20% (e.g. through transference of
technology for improving agriculture and aquaculture production)
and demand by 2050 decreased by reducing CO2 emissions and fisheries
catches by 50%, and by stabilizing urban land expansion among other
things. Using Kitzes et al.’s (2008) ‘rapid reduction’ scenario,
we modeled the tendency of to reach zero in 2050
(‘sustainability by 2050’ scenario) and calculated the ecological
demand and number of people under that scenario accordingly. That
result suggests that to get out of an by 2050, we would
have to implement the conditions of the ‘rapid reduction’ scenario
plus stabilize human population at its current size (see dotted line
in [a]). This could be achieved by reducing the current birth rate
of 0.01995 to the current mortality rate of 0.0082 or ~1 child per
women by 2050. As reference we also provide projections given current
human consumption (i.e. 2.1 ha per person) and no further natality
(‘zero natality’ scenario)
(Source: Camilo Mora et al.)
Limitations of the Current Conservation Strategy
Dr. Mora et al. point out the 5 limitations of existing conservation strategies:
Expected growth in protected area coverage is too slow
- Over 100,000 areas are now protected worldwide but strict enforcement occurs on just 5.8% of land and 0.08% of ocean
- 30% is the minimum target widely advocated for effective biodiversity conservation
- At current rates, it will take 185 years in the case of land and 80 years for oceans to protect this 30%
- The rapid rate of climate change, habitat loss and resource exploitation is predicted to cause the extinction of many species even before 2050
- Therefore, the conservation rate is far too slow to have any real impact
Inadequate Size and Connectivity of Protected Areas
- Protected areas must be sufficiently large to sustain viable populations in the face of the inevitable mortality of some individuals trespassing their borders
- Areas must be close enough together for a healthy exchange of individuals among protected populations
- Globally over 30% of the protected areas in the ocean, and 60% on land are smaller than 1 square kilometer — too small for many larger species
- They are too far apart to allow a sufficient exchange among populations for most species
Protected Areas do not Protect Against All Human Threats
Biodiversity loss is triggered by human stressors including:
- habitat loss
- climate change
- invasive species
Protected areas are useful only against overexploitation and habitat loss. The other three will continue to increase biodiversity loss. Approximately 83% of protected areas on the sea and 95% of protected areas on land are located in areas with continuing high impact from multiple human stressors.
- Effective management in existing protected areas requires an estimated $24 billion per year
- Global expenditures on protected areas in 2011 are estimated at US $6 billion per year
- Budget growth has been slow and is unlikely to reach adequate levels of protection for existing or for adding new protected areas
Conflicts with human development
- Humanity’s footprint on Earth continues to expand to meet human development needs
- Placing 30% of world habitats under protection will lead to intense conflicts with competing human interests– many people would be displaced and livelihoods impaired
- Forcing a trade-off between human development and sustaining biodiversity is unlikely to lead to a solution with biodiversity preserved
Continuing to apply the current conservation approach of creating more protected areas will continue the biodiversity loss. The only real alternative is to get serious about reducing our.
The Impact of vanishing Apex Predators
Figure 8: Impacts of top predators absence or presence (Source: Trophic downgrading of planet earth)
Figure 9: Impacts of top predators absence or presence (Source: Trophic downgrading of planet earth)
Figure 10: Impacts of top predators absence or presence (Source: Trophic downgrading of planet earth)
Figure 11: Impacts of loss of top predators on ecological parameters (Source: Trophic downgrading of planet earth)
Figure 12: Species increase and decrease as a result of Apex predator decline (Source: Status and Ecological Effects of the World’s Largest Carnivores)
Figure 13: Wolf apex predator trophic effects on other species (Source: Status and Ecological Effects of the World’s Largest Carnivores)
Figure 14: Impact of various factors on declining apex predators (Source: Status and Ecological Effects of the World’s Largest Carnivores)