Environment Disadvantage-4wkj-ndi



Download 0.83 Mb.
Page8/16
Date13.05.2016
Size0.83 Mb.
1   ...   4   5   6   7   8   9   10   11   ...   16

Impact Scenarios




General Extinction

Biodiversity loss is as devastating as climate change and pollution


Green Building Elements 12 (“Biodiversity Loss Ranks with Climate Change and Pollution in Terms of Impacts to Environment”, May 10, 2012, http://www.lexisnexis.com.turing.library.northwestern.edu/hottopics/lnacademic/) BC

The "Flume Room" at the University of Michigan is used to assess how species diversity affects water quality in streams.

A recent study published by an international research team working at UC Santa Barbara s National Center for Ecological Analysis and Synthesis (NCEAS) has found that loss of biodiversity impacts the environment as significantly as climate change and pollution. The study, titled, a global synthesis reveals biodiversity loss as a major driver of ecosystem change, was published May 2 in the journal Nature. For the past 15 years, ecologists have built a rich understanding of the consequences of humans driving species extinct. What we didn't know before this paper is whether those impacts of species loss rank up there with those from the major drivers of environmental change, said Jarrett Byrnes, a postdoctoral fellow with NCEAS.

Led by Western Washington University biologist David Hooper, the scientists, including those from institutions in the U.S., Canada, and Sweden, examined the effects of various environmental stressors on plant growth and decomposition, two crucial processes in any ecosystem. With data synthesized from almost 200 published studies, they measured the rate of species loss in different ecosystems, and found that the greater the plant species loss, the higher the negative impact on plant growth. The effects of biodiversity loss on biomass were similar to the effects from other environmental stressors, including global warming and pollution. Our work shows that, indeed, the impacts of species loss look to be on par with many kinds of human-driven environmental change, said Byrnes. And more intriguingly, it suggests that if environmental change also causes loss of species, ecosystem functions like productivity could get hit with a 1-2 punch. The news looks bleak, with some projections suggesting that, at the current rate of biodiversity loss, Earth may face another mass extinction within 240 years. To combat this scenario, said Byrnes, species loss has to be considered alongside the more prominent forms of environmental change. Researcher measuring the productivity of algae in a stream. For the researchers, there is more to be studied, as they plan to dig deeper into the effects of species loss on multiple functions and explicitly link loss of species to changes in ecosystem services. One thing this study opens up is the need to better understand the interactions between environmental change and species loss. They’re not independent, and may interact in some particularly unexpected ways, said Byrnes.


Ocean biodiversity loss will result in a domino effect resulting in extinction.


McCarthy 11(Michael McCarthy , award winning environmental journalist & editor, “Oceans on the brink of catastrophe,” The Independent, June 21, Online: http://www.independent.co.uk/environment/nature/oceans-on-brink-of-catastrophe-2300272.html) The world's oceans are faced with an unprecedented loss of species comparable to the great mass extinctions of prehistory, a major report suggests today. The seas are degenerating far faster than anyone has predicted, the report says, because of the cumulative impact of a number of severe individual stresses, ranging from climate warming and sea-water acidification, to widespread chemical pollution and gross overfishing. The coming together of these factors is now threatening the marine environment with a catastrophe "unprecedented in human history", according to the report, from a panel of leading marine scientists brought together in Oxford earlier this year by the International Programme on the State of the Ocean (IPSO) and the International Union for the Conservation of Nature (IUCN).¶ The stark suggestion made by the panel is that the potential extinction of species, from large fish at one end of the scale to tiny corals at the other, is directly comparable to the five great mass extinctions in the geological record, during each of which much of the world's life died out. They range from the Ordovician-Silurian "event" of 450 million years ago, to the Cretaceous-Tertiary extinction of 65 million years ago, which is believed to have wiped out the dinosaurs. The worst of them, the event at the end of the Permian period, 251 million years ago, is thought to have eliminated 70 per cent of species on land and 96 per cent of all species in the sea.¶ The panel of 27 scientists, who considered the latest research from all areas of marine science, concluded that a "combination of stressors is creating the conditions associated with every previous major extinction of species in Earth's history". They also concluded the speed and rate of degeneration of the oceans is far faster than anyone has predicted; ¶ * Many of the negative impacts identified are greater than the worst predictions; ¶ * the first steps to globally significant extinction may have already begun.

Biodiversity loss leads to Extinction


Tschakert et. al. 12 (Dr. Tschakert received a PhD in arid lands resources science from the University of Arizona and a mag. Phil in geography and economic from Karl-Franzens University, “Human Extinction”, https://www.e-education.psu.edu/geog030/node/398) Earlier in this module, we used the house of cards (or Jenga) metaphor for ecosystem resilience. As more species go extinct, it becomes more likely for ecosystems to collapse. Given how many species are endangered, it is difficult to put an upper limit on how severe the ecosystem collapses could be. The collapses could be so severe that human extinction is threatened. The current honey bee colony collapse situation illustrates this. Without honey bees, humans would struggle - and perhaps fail - to grow many important crops. As more biodiversity is lost, we may find ourselves learning the hard way how important it is to our civilization and indeed our very survival.

Biodiversity poses an imminent threat to human survival


Raj 12 (Dr. P.J. Sanjeeva Raj, consultant ecologist and the Professor and Head of the Zoology Department of the Madras Christian College (MCC), “Beware the loss of biodiversity”, September 23, 2012, http://www.thehindu.com/opinion/open-page/beware-the-loss-of-biodiversity/article3927062.ece) Professor Edward O. Wilson, Harvard visionary of biodiversity, observes that the current rate of biodiversity loss is perhaps the highest since the loss of dinosaurs about 65 million years ago during the Mesozoic era, when humans had not appeared. He regrets that if such indiscriminate annihilation of all biodiversity from the face of the earth happens for anthropogenic reasons, as has been seen now, it is sure to force humanity into an emotional shock and trauma of loneliness and helplessness on this planet. He believes that the current wave of biodiversity loss is sure to lead us into an age that may be appropriately called the “Eremozoic Era, the Age of Loneliness.” Loss of biodiversity is a much greater threat to human survival than even climate change. Both could act, synergistically too, to escalate human extinction faster.

Biodiversity is so indispensable for human survival that the United Nations General Assembly has designated the decade 2011- 2020 as the ‘Biodiversity Decade’ with the chief objective of enabling humans to live peaceably or harmoniously with nature and its biodiversity. We should be happy that during October 1-19, 2012, XI Conference of Parties (CoP-11), a global mega event on biodiversity, is taking place in Hyderabad, when delegates from 193 party countries are expected to meet. They will review the Convention on Biological Diversity (CBD), which was originally introduced at the Earth Summit or the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in 1992. The Ministry of Environment and Forests (MoEF) is the nodal agency for CoP-11. Today, India is one of the 17 mega-diverse (richest biodiversity) countries. Biodiversity provides all basic needs for our healthy survival — oxygen, food, medicines, fiber, fuel, energy, fertilizers, fodder and waste-disposal, etc. Fast vanishing honeybees, dragonflies, bats, frogs, house sparrows, filter (suspension)-feeder oysters and all keystone species are causing great economic loss as well as posing an imminent threat to human peace and survival. The three-fold biodiversity mission before us is to inventories the existing biodiversity, conserve it, and, above all, equitably share the sustainable benefits out of it.

Loss of biodiversity has the capacity to cause human extinction


Buczynski 10 (Beth Buczynski is the author of Sharing is Good (Fall 2013, New Society Publishers), a practical guide to collaborative consumption that includes hundreds of tips and resources to help you participate in the growing sharing economy. She received a BA in creative writing from the University of Tennessee and a MS in public communication and technology from Colorado State University, “UN: Loss Of Biodiversity Could Mean End Of Human Race”, http://www.care2.com/causes/un-humans-are-rapidly-destroying-the-biodiversity-ne.html#ixzz2ZXlGvUz0)

UN officials gathered at the Convention on Biological Diversity (CBD) in Japan have issued a global warning that the rapid loss of animal and plant species that has characterized the past century must end if humans are to survive. Delegates in Nagoya plan to set a new target for 2020 for curbing species loss, and will discuss boosting medium-term financial help for poor countries to help them protect their wildlife and habitats (Yahoo Green). “Business as usual is no more an option for mankind,” CBD executive secretary Ahmed Djoghlaf said in his opening statements. “We need a new approach, we need to reconnect with nature and live in harmony with nature into the future.” The CBD is an international legally-binding treaty with three main goals: conservation of biodiversity; sustainable use of biodiversity; fair and equitable sharing of the benefits arising from the use of genetic resources. Its overall objective is to encourage actions which will lead to a sustainable future. As Djoghlaf acknowledged in his opening statements, facing the fact that many countries have ignored their obligation to these goals is imperative if progress is to be made in the future. “Let us have the courage to look in the eyes of our children and admit that we have failed, individually and collectively, to fulfill the Johannesburg promise made to them by the 110 Heads of State and Government to substantially reduce the loss of biodiversity by 2010,” Djoghlaf stated. “Let us look in the eyes of our children and admit that we continue to lose biodiversity at an unprecedented rate, thus mortgaging their future. “Earlier this year, the U.N. warned several eco-systems including the Amazon rainforest, freshwater lakes and rivers and coral reefs are approaching a “tipping point” which, if reached, may see them never recover. According to a study by UC Berkeley and Penn State University researchers, between 15 and 42 percent of the mammals in North America disappeared after humans arrived. Compared to extinction rates demonstrated in other periods of Earth’s history, this means that North American species are already half way to a sixth mass extinction, similar to the one that eliminated the dinosaurs. The same is true in many other parts of the world. The third edition of the Global Biodiversity Outlook demonstrates that, today, the rate of loss of biodiversity is up to one thousand times higher than the background and historical rate of extinction. The Earth’s 6.8 billion humans are effectively living 50 percent beyond the planet’s bio capacity in 2007; according to a new assessment by the World Wildlife Fund that said by 2030 humans will effectively need the capacity of two Earths in order to survive


Species loss can lead to extinction


King et. al. 12 (Petra Tschakert, Assistant Professor of Geography; Karl Zimmerer, Professor and Department Head of Geography; Brian King, Assistant Professor of Geography; Seth Baum, Graduate Assistant and Ph.D. student in Geography and Chongming Wang, Teaching Assistant, Geography, “Human Extinction“,https://www.e-education.psu.edu/geog030/node/398, MS) Biodiversity loss. Earlier in this module, we used the house of cards (or Jenga) metaphor for ecosystem resilience. As more species go extinct, it becomes more likely for ecosystems to collapse. Given how many species are endangered, it is difficult to put an upper limit on how severe the ecosystem collapses could be. The collapses could be so severe that human extinction is threatened. The current honey bee colony collapse situation illustrates this. Without honey bees, humans would struggle - and perhaps fail - to grow many important crops. As more biodiversity is lost, we may find ourselves learning the hard way how important it is to our civilization and indeed our very survival.


Loss of Biodiversity leads to loss of resources


Weidema No date (Bo P.Weidema., M.Sc. in horticulture from the Royal Agricultural University of Copenhagen, “Can resource depletion be omitted from environmental impact assessments? http://www.lca-net.com/files/resources-postertext.pdf, MS) Present rate of extinction of species is estimated upwards from 1000 species per year (out of an¶ estimated total of 14*109 species). It is generally agreed that the reduction in biodiversity is caused by over-exploitation of specific species (hunting and deliberate extermination), introduction of new¶ species, and habitat destruction.¶ As a protection area, biodiversity is affected not only by direct or indirect use of biological resources (over-exploitation of specific species and physical habitat destruction) but also by many environmental mechanisms, both those typically included in environmental assessments (global¶ warming, ozone depletion, acidification, eutrophication etc.) and such which are not so often included (e.g. introduction of new species). In this presentation, I deal only with those effects that¶ are related to direct or indirect use of biological resources.¶ Over-exploitation of specific species, i.e. harvesting of species which are threatened with extinction, may be recorded as a resource use in the inventory (e.g. expressed in terms of numbers of¶ individuals, weight or area exploited, allowing a later assessment of the size of the impact in¶ relation to the size of the remaining and/or viable population and the value assigned to the species¶ in question).¶ Physical habitat destruction may be recorded in the inventory in terms of both the area affected (when a change in habitat quality is implied) and area*time (to cover the effects of the mere¶ occupation of an area). In the impact assessment, these inventory items may be weighted with coefficients expressing the specific characteristics of the affected area in relation to the species density relative to the average species density, the scarcity of areas where the specific ecosystem can exist, and the scarcity of areas where the specific ecosystem actually exists. This concept is¶ further developed in Weidema & Lindeijer (2001).

Biodiversity stabilizes Earth’s Ecosystems


Calzadilla 13 (Erasmo Calzadilla, the General Assembly of the United Nations, “Cuba and its Biodiversity”, May 24, 2013, http://humanrightsincuba.blogspot.com/2013/05/cuba-and-its-biodiversity.html, MS)

HAVANA TIMES — In 2000, with the aim of alerting humanity to the extinction of ecosystems, species and genes and the accelerated decline in biodiversity it was causing, the United Nations' General Assembly ¶ declared May 22 International Day for Biological Biodiversity. ¶ One may think that, ultimately, humanity does not need so many bugs ¶ around it to get by, that it is an aesthetic, or, at most, an ethical ¶ issue. Nothing could be further from the truth. ¶ In addition to all of the direct or indirect "services" these bugs ¶ offer, diversity is the stabilizer of the biosphere, its shield against disturbances and aggressions. Without it, we're toast. We are the species with the most sophisticated brain the earth has ever known and we behave like a lowly plague attacking a planet. We're a sorry sight indeed.



Life is dependent on the environment


Ash and Fazel, 7 (Neville and Ashgar, Neville Ash heads the Ecosystem Assessment Programme of the United Nations Environment Programme World Conservation Monitoring Centre and Senior Advisor at UNEP-WCMC ¶ Lecturer, Dean, Chancellor at University of Environment ¶ CBD/SBSTTA Chair at UNCBD, “Biodiversity”, NO DATE, http://www.unep.org/geo/geo4/report/05_Biodiversity.pdf)

Human health is affected by changes in biodiversity and ecosystem services.¶ Changes to the environment have altered disease patterns and human exposure to disease outbreaks. In addition,¶ current patterns of farming, based on high resource inputs (such as water and¶ fertilizers) and agricultural intensification, are putting great strains on ecosystems,¶ contributing to nutritional imbalances and¶ reduced access to wild foods.¶ �� Human societies everywhere have depended on biodiversity for cultural identity, spirituality, inspiration, aesthetic enjoyment and recreation. Culture can¶ also play a key role in the conservation¶ and sustainable use of biodiversity. Loss of biodiversity affects both material and non-material human well-beings. Both the continued loss of biodiversity and the disruption of cultural integrity represent obstacles towards the attainment of the Millennium Development Goals (MDGs).¶ Biodiversity loss continues because current¶ policies and economic systems do not incorporate¶ the values of biodiversity effectively in either¶ the political or the market systems, and many¶ current policies are not fully implemented.¶ Although many losses of biodiversity,¶ including the degradation of ecosystems, are¶ slow or gradual, they can lead to sudden and dramatic declines in the capacity of biodiversity to contribute to human wellbeing



Each instance increases the risk of extinction- evaluate linear risk of net benefit


Major David N. Diner, U.S. Army, 94 [“The Army and the Endangered Species Act: Who’s Endangering Whom?” Military Law Review. 143 Mil. L. Rev. 161. Winter, 1994, LEXIS] By causing widespread extinctions, humans have artificially simplified many ecosystems. As biologic simplicity increases, so does the risk of ecosystem failure. The spreading Sahara Desert in Africa, and the dustbowl conditions of the 1930s in the United States are relatively mild examples of what might be expected if this trend continues. Theoretically, each new animal or plant extinction, with all its dimly perceived and intertwined affects, could cause total ecosystem collapse and human extinction. Each new extinction increases the risk of disaster. Like a mechanic removing, one by one, the rivets from an aircraft's wings, 80 mankind may be edging closer to the abyss.

Biodiversity loss will cause planetary extinction


Diner 93 (David N. Diner is the judge advocate general’s corps of US Army, “THE ARMY AND THE ENDANGERED SPECIES ACT: WHO' S ENDANGERING WHOM?”, April, 1993, http://www.dtic.mil/dtic/tr/fulltext/u2/a456541.pdf (pg. 11-14))

No species has ever dominated its fellow species as man has. In most cases, people have assumed the God-like power of life and death -- extinction or survival -- over the plants and animals of the world. For most of history, mankind pursued this domination with a single-minded determination to master the world, tame the wilderness, and exploit nature for the maximum benefit of the human race. N67 In past mass extinction episodes, as many as ninety percent of the existing species perished, and yet the world moved forward, and new species replaced the old. So why the world should be concerned now? The prime reason is the world's survival. Like all animal life, humans live off of other species. At some point, the number of species could decline to the point at which the ecosystem fails, and then humans also would become extinct. No one knows how many [*171] species the world needs to support human life, and to find out -- by allowing certain species to become extinct -- would not be sound policy. In addition to food, species offer many direct and indirect benefits to mankind. n68 2. Ecological Value. -- Ecological value is the value that species have in maintaining the environment. Pest, n69 erosion, and flood control are prime benefits certain species provide to man. Plants and animals also provide additional ecological services -- pollution control, oxygen production, sewage treatment, and biodegradation. n71 3. Scientific and Utilitarian Value. -- Scientific value is the use of species for research into the physical processes of the world. Without plants and animals, a large portion of basic scientific research would be impossible. Utilitarian value is the direct utility humans draw from plants and animals. Only a fraction of the [*172] earth's species have been examined, and mankind may someday desperately need the species that it is exterminating today. To accept that the snail darter, harelip sucker, or Dismal Swamp southeastern shrew n74 could save mankind may be difficult for some. Many, if not most, species are useless to man in a direct utilitarian sense. Nonetheless, they may be critical in an indirect role, because their extirpations could affect a directly useful species negatively. In a closely interconnected ecosystem, the loss of a species affects other species dependent on it. n75 Moreover, as the number of species decline, the effect of each new extinction on the remaining species increases dramatically. n76 4. Biological Diversity. -- The main premise of species preservation is that diversity is better than simplicity. n77 As the current mass extinction has progressed, the world's biological diversity generally has decreased. This trend occurs within ecosystems by reducing the number of species, and within species by reducing the number of individuals. Both trends carry serious future implications. Biologically diverse ecosystems are characterized by a large number of specialist species, filling narrow ecological niches. These ecosystems inherently are more stable than less diverse systems. "The more complex the ecosystem, the more successfully it can resist a stress. . . . [l]ike a net, in which each knot is connected to others by several strands, such a fabric can resist collapse better than a simple, unbranched circle of threads -- which if cut anywhere breaks down as a whole." n79 By causing widespread extinctions, humans have artificially simplified many ecosystems. As biologic simplicity increases, so does the risk of ecosystem failure. The spreading Sahara Desert in Africa, and the dustbowl conditions of the 1930s in the United States are relatively mild examples of what might be expected if this trend continues. Theoretically, each new animal or plant extinction, with all its dimly perceived and intertwined affects, could cause total ecosystem collapse and human extinction. Each new extinction increases the risk of disaster. Like a mechanic removing, one by one, the rivets from an aircraft's wings, [hu]mankind may be edging closer to the abyss.

These environmental hotspots are vital for human survival


Nautiyal & Nidamanuri 10 (Centre for Ecological Economics and Natural Resources @ Institute for Social and Economic Change & Department of Earth and Space Sciences @ Indian Institute of Space Science and Technology [SUNIL NAUTIYAL1 & RAMA RAO NIDAMANURI “Conserving Biodiversity in Protected Area of Biodiversity Hotspot in India: A Case Study,” International Journal of Ecology and Environmental Sciences 36 (2-3): 195-200, 2010) The hotspots are the world’s most biologically rich areas hence recognized as important ecosystems not importantonly for the rich biodiversity but equally important for the human survival as these are the homes for more than¶ 20% of the world’s population. India got recognition of one of the mega-diversity countries of world as the country¶ is home of the two important biodiversity hotspots: the Himalaya in north and the Western Ghats in the southern¶ peninsula. Policy makers and decision takers have recognized the importance of biodiversity (flora and fauna) and¶ this has resulted to segregate (in the form of protected areas) the rich and diverse landscape for biodiversity¶ conservation. An approach which leads towards conservation of biological diversity is good efforts but suchapproaches should deal with humans equally who are residing in biodiversity hotspots since time immemorial. In¶ this endeavor, a study was conducted in Nagarahole National Park of Nilgiri Biosphere Reserve, in Karnataka. Our¶ empirical studies reveal that banning all the human activities in this ecosystem including agriculture, animal¶ husbandry has produced the results opposite to the approach ‘multiple values’ of national park. To monitor the¶ impact, existing policies have been tested from an economic and ecological view-point. Unfortunately, the local¶ livelihoods (most of them belongs to indigenous tribes) in the area have received setbacks due to the¶ implementation of the policies, though unintentionally. However, the ecological perspective is also not showing¶ support for the approach and framework of the current policies in the hotspots. Satellite data showed that the¶ temporal pattern of ecosystem processes has been changing. An integrated approach for ecosystem conservation and¶ strengthening local institutions for sustainable ecosystem management in such areas is therefore supported by this¶ study.

Some species carry more weight than others, making their loss catastrophic- Just like the Miami Heat Losing Lebron James


Lemonick, 12 (Michael D. Lemonick, Senior science writer at Time magazine in New York ”How Biodiversity Loss is Like LeBron James & Miami Heat”, Jun 9, 2012, http://thinkprogress.org/climate/2012/06/09/495988/how-biodiversity-loss-is-like-lebron-james-amp-miami-heat/?mobile=nc, MS) Ecologists have been saying for decades now that the world is in the midst of a biodiversity crisis. Hundreds of species are vanishing every year, thanks to assaults to the environment that include deforestation, overfishing, toxic pollution and, increasingly, climate change — the lethal icing on an already poisoned cake. Twenty years ago, 150 countries signed the international Convention on Biodiversity to try and hold back the tide of extermination, but without much success: Scientists are now saying the planet may be going through its sixth mass extinction in the past 540 million years, and the first caused by humans.¶ But experts haven’t been so good at explaining exactly why this is such a terrible thing. “Most of the arguments have been based on the idea that biodiversity has some intrinsic value,” said Bradley Cardinale, an ecologist at the University of Michigan, in an interview yesterday. “We like it. It’s pretty. The Pope says we should conserve God’s creation. Maybe we’ll find new medicinal plants in the rainforest.”¶ In a new paper just published in Nature, however, Cardinale and 17 colleagues have made a much more solid argument. “We’re saying that biodiversity does things that are really important,” he said. “There’s really strong evidence that if we lose biodiversity, it will, among other things, affect food production and fresh water supplies and increase the frequency of pests and diseases that affect crops and animals.”¶ The paper is what’s known as a meta-analysis: the 18 authors, all of them leaders in the field of ecology, gathered more than a thousand studies published over the past 20 years that looked at biodiversity from a myriad of angles. Then they looked at whether differences in biodiversity affected an ecosystem’s ability to do useful things — the ability of a forest to remove carbon from the atmosphere, for example, or supply wood for construction; the ability of bacteria in a stream to neutralize pollutants; the ability of natural predators and parasites to control agricultural pests.¶ The answer, it turns out, is yes, to these and many other similar questions. In many cases, it boils down to two primary reasons. The first is that the most diverse ecosystems tend to include what the scientists call “super species.” Say you’re talking about the capacity of a diverse forest to produce wood, or to take carbon from the air, Cardinale said.¶ “About 50 percent of that effect will come from a single, highly productive species,” he said. The other half comes from a wide variety of other species that occupy different niches, grow at different rates. “It’s like the Miami Heat,” he said. “Half of their productivity comes from LeBron James, but without a strong supporting cast of players, that would not be enough.”

Biodiversity loss impact comparable to global warming impact


National Science Foundation 12 (Ecosystem Effects of Biodiversity Loss Rival Climate Change and Pollution, 5/2, http://www.nsf.gov/news/news_summ.jsp?cntn_id=124016) Loss of biodiversity appears to affect ecosystems as much as climate change, pollution and other major forms of environmental stress, according to results of a new study by an international research team.¶ The study is the first comprehensive effort to directly compare the effects of biological diversity loss to the anticipated effects of a host of other human-caused environmental changes.¶ The results, published in this week's issue of the journal Nature, highlight the need for stronger local, national and international efforts to protect biodiversity and the benefits it provides, according to the researchers, who are based at nine institutions in the United States, Canada and Sweden.¶ "This analysis establishes that reduced biodiversity affects ecosystems at levels comparable to those of global warming and air pollution," said Henry Gholz, program director in the National Science Foundation's Division of Environmental Biology, which funded the research directly and through the National Center for Ecological Analysis and Synthesis.¶ "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.¶ "Our results show that future loss of species has the potential to reduce plant production just as much as global warming and pollution."¶ Studies over the last two decades demonstrated that more biologically diverse ecosystems are more productive.¶ As a result, there has been growing concern that 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 goods and services such as food, clean water and a stable climate.¶ Until now, it's been unclear how biodiversity losses stack up against other human-caused environmental changes that affect ecosystem health and productivity.¶ "Loss of biological diversity due to species extinctions is going to have major effects on our planet, and we need to prepare ourselves to deal with them," said ecologist Bradley Cardinale of the University of Michigan, one of the paper's co-authors. "These extinctions may well rank as one of the top five drivers of global change."¶ In the study, Hooper, Cardinale and colleagues combined data from a large number of published studies to compare how various global environmental stressors affect two processes important in ecosystems: plant growth and the decomposition of dead plants by bacteria and fungi.¶ The study involved the construction of a database drawn from 192 peer-reviewed publications about experiments that manipulated species richness and examined their effect on ecosystem processes.¶ This global synthesis found that in areas where local species loss during this century falls within the lower range of projections (losses of 1 to 20 percent of plant species), negligible effects on ecosystem plant growth will result, and changes in species richness will rank low relative to the effects projected for other environmental changes.¶ In ecosystems where species losses fall within intermediate projections of 21 to 40 percent of species, however, species loss is expected to reduce plant growth by 5 to 10 percent.¶ The effect is comparable to the expected effects of climate warming and increased ultraviolet radiation due to stratospheric ozone loss.¶ At higher levels of extinction (41 to 60 percent of species), the effects of species loss ranked with those of many other major drivers of environmental change, such as ozone pollution, acid deposition on forests and nutrient pollution.¶ "Within the range of expected species losses, we saw average declines in plant growth that were as large as changes in experiments simulating several other major environmental changes caused by humans," Hooper said.¶ "Several of us working on this study were surprised by the comparative strength of those effects."¶ The strength of the observed biodiversity effects suggests that policymakers searching for solutions to other pressing environmental problems should be aware of potential adverse effects on biodiversity as well.¶ Still to be determined is how diversity loss and other large-scale environmental changes will interact to alter ecosystems.¶ "The biggest challenge looking forward is to predict the combined effects of these environmental challenges to natural ecosystems and to society," said J. Emmett Duffy of the Virginia Institute of Marine Science, a co-author of the paper.¶ Authors of the paper, in addition to Hooper, Cardinale and Duffy, are E. Carol Adair of the University of Vermont and the National Center for Ecological Analysis and Synthesis; Jarrett Byrnes of the National Center for Ecological Analysis and Synthesis; Bruce Hungate of Northern Arizona University; Kristen Matulich of University of California, Irvine; Andrew Gonzales of McGill University; Lars Gamfeldt of the University of Gothenburg; and Mary O'Connor of the University of British Columbia and the National Center for Ecological Analysis and Synthesis.
Decrease in biodiversity will lead to extinction

Craig 3 (Robin Kundis Craig, “Taking Steps Toward Marine Wilderness Protection? Fishing and Coral Reef Marine Reserves in Florida and Hawaii,” Winter 2003, 34 McGeorge Law Review 155, Attorneys’ Title Professor of Law and Associate Dean for Environmental Programs at Florida State University) Biodiversity and ecosystem function arguments for conserving marine ecosystems also exist, just as they do for terrestrial ecosystems, but these arguments have thus far rarely been raised in political debates. For example, besides significant tourism values - the most economically valuable ecosystem service coral reefs provide, worldwide - coral reefs protect against storms and dampen other environmental fluctuations, services worth more than ten times the reefs' value for food production. Waste treatment is another significant, non-extractive ecosystem function that intact coral reef ecosystems provide. More generally, "ocean ecosystems play a major role in the global geochemical cycling of all the elements that represent the basic building blocks of living organisms, carbon, nitrogen, oxygen, phosphorus, and sulfur, as well as other less abundant but necessary elements." In a very real and direct sense, therefore, human degradation of marine ecosystems impairs the planet's ability to support life. Maintaining biodiversity is often critical to maintaining the functions of marine ecosystems. Current evidence shows that, in general, an ecosystem's ability to keep functioning in the face of disturbance is strongly dependent on its biodiversity, "indicating that more diverse ecosystems are more stable." Coral reef ecosystems are particularly dependent on their biodiversity. Most ecologists agree that the complexity of interactions and degree of interrelatedness among component species is higher on coral reefs than in any other marine environment. This implies that the ecosystem functioning that produces the most highly valued components is also complex and that many otherwise insignificant species have strong effects on sustaining the rest of the reef system. Thus, maintaining and restoring the biodiversity of marine ecosystems is critical to maintaining and restoring the ecosystem services that they provide. Non-use biodiversity values for marine ecosystems have been calculated in the wake of marine disasters, like the Exxon Valdez oil spill in Alaska. Similar calculations could derive preservation values for marine wilderness. However, economic value, or economic value equivalents, should not be "the sole or even primary justification for conservation of ocean ecosystems. Ethical arguments also have considerable force and merit." At the forefront of such arguments should be a recognition of how little we know about the sea - and about the actual effect of human activities on marine ecosystems. The United States has traditionally failed to protect marine ecosystems because it was difficult to detect anthropogenic harm to the oceans, but we now know that such harm is occurring - even though we are not completely sure about causation or about how to fix every problem. Ecosystems like the NWHI coral reef ecosystem should inspire lawmakers and policymakers to admit that most of the time we really do not know what we are doing to the sea and hence should be preserving marine wilderness whenever we can - especially when the United States has within its territory relatively pristine marine ecosystems that may be unique in the world. We may not know much about the sea, but we do know this much: if we kill the ocean we kill ourselves, and we will take most of the biosphere with us. The Black Sea is almost dead, its once-complex and productive ecosystem almost entirely replaced by a monoculture of comb jellies, "starving out fish and dolphins, emptying fishermen's nets, and converting the web of life into brainless, wraith-like blobs of jelly." More importantly, the Black Sea is not necessarily unique. The Black Sea is a microcosm of what is happening to the ocean systems at large. The stresses piled up: overfishing, oil spills, industrial discharges, nutrient pollution, wetlands destruction, the introduction of an alien species. The sea weakened, slowly at first, then collapsed with shocking suddenness. The lessons of this tragedy should not be lost to the rest of us, because much of what happened here is being repeated all over the world. The ecological stresses imposed on the Black Sea were not unique to communism. Nor, sadly, was the failure of governments to respond to the emerging crisis. Oxygen-starved "dead zones" appear with increasing frequency off the coasts of major cities and major rivers, forcing marine animals to flee and killing all that cannot. Ethics as well as enlightened self-interest thus suggest that the United States should protect fully-functioning marine ecosystems wherever possible - even if a few fishers go out of business as a result.

Biodiversity is key to our survival

Young 10 (Dr. Ruth Young, “Biodiversity: what it is and why it’s important”, 2/9/10, http://www.talkingnature.com/2010/02/biodiversity/biodiversity-what-and-why/ PB, PhD in coastal marine ecology) Different species within ecosystems fill particular roles, they all have a function, they all have a niche. They interact with each other and the physical environment to provide ecosystem services that are vital for our survival. For example plant species convert carbon dioxide (CO2) from the atmosphere and energy from the sun into useful things such as food, medicines and timber. Pollination carried out by insects such as bees enables the production of ⅓ of our food crops. Diverse mangrove and coral reef ecosystems provide a wide variety of habitats that are essential for many fishery species. To make it simpler for economists to comprehend the magnitude of services offered by biodiversity, a team of researchers estimated their value – it amounted to $US33 trillion per year. “By protecting biodiversity we maintain ecosystem services” Certain species play a “keystone” role in maintaining ecosystem services. Similar to the removal of a keystone from an arch, the removal of these species can result in the collapse of an ecosystem and the subsequent removal of ecosystem services. The most well-known example of this occurred during the 19th century when sea otters were almost hunted to extinction by fur traders along the west coast of the USA. This led to a population explosion in the sea otters’ main source of prey, sea urchins. Because the urchins graze on kelp their booming population decimated the underwater kelp forests. This loss of habitat led to declines in local fish populations. Sea otters are a keystone species once hunted for their fur (Image: Mike Baird) Eventually a treaty protecting sea otters allowed the numbers of otters to increase which inturn controlled the urchin population, leading to the recovery of the kelp forests and fish stocks. In other cases, ecosystem services are maintained by entire functional groups, such as apex predators (See Jeremy Hance’s post at Mongabay). During the last 35 years, over fishing of large shark species along the US Atlantic coast has led to a population explosion of skates and rays. These skates and rays eat bay scallops and their out of control population has led to the closure of a century long scallop fishery. These are just two examples demonstrating how biodiversity can maintain the services that ecosystems provide for us, such as fisheries. One could argue that to maintain ecosystem services we don’t need to protect biodiversity but rather, we only need to protect the species and functional groups that fill the keystone roles. However, there are a couple of problems with this idea. First of all, for most ecosystems we don’t know which species are the keystones! Ecosystems are so complex that we are still discovering which species play vital roles in maintaining them. In some cases its groups of species not just one species that are vital for the ecosystem. Second, even if we did complete the enormous task of identifying and protecting all keystone species, what back-up plan would we have if an unforseen event (e.g. pollution or disease) led to the demise of these ‘keystone’ species? Would there be another species to save the day and take over this role? Classifying some species as ‘keystone’ implies that the others are not important. This may lead to the non-keystone species being considered ecologically worthless and subsequently over-exploited. Sometimes we may not even know which species are likely to fill the keystone roles. An example of this was discovered on Australia’s Great Barrier Reef. This research examined what would happen to a coral reef if it were over-fished. The “over-fishing” was simulated by fencing off coral bommies thereby excluding and removing fish from them for three years. By the end of the experiment, the reefs had changed from a coral to an algae dominated ecosystem – the coral became overgrown with algae. When the time came to remove the fences the researchers expected herbivorous species of fish like the parrot fish (Scarus spp.) to eat the algae and enable the reef to switch back to a coral dominated ecosystem. But, surprisingly, the shift back to coral was driven by a supposed ‘unimportant’ species – the bat fish (Platax pinnatus). The bat fish was previously thought to feed on invertebrates – small crabs and shrimp, but when offered a big patch of algae it turned into a hungry herbivore – a cow of the sea – grazing the algae in no time. So a fish previously thought to be ‘unimportant’ is actually a keystone species in the recovery of coral reefs overgrown by algae! Who knows how many other species are out there with unknown ecosystem roles! In some cases it’s easy to see who the keystone species are but in many ecosystems seemingly unimportant or redundant species are also capable of changing niches and maintaining ecosystems. The more biodiverse an ecosystem is, the more likely these species will be present and the more resilient an ecosystem is to future impacts. Presently we’re only scratching the surface of understanding the full importance of biodiversity and how it helps maintain ecosystem function. The scope of this task is immense. In the meantime, a wise insurance policy for maintaining ecosystem services would be to conserve biodiversity. In doing so, we increase the chance of maintaining our ecosystem services in the event of future impacts such as disease, invasive species and of course, climate change. This is the international year of biodiversity a time to recognize that biodiversity makes our survival on this planet possible and that our protection of biodiversity maintains this service.




Share with your friends:
1   ...   4   5   6   7   8   9   10   11   ...   16


The database is protected by copyright ©essaydocs.org 2019
send message

    Main page