Overpopulation does not depend only on the size or density of the population, but on the ratio of population to available sustainable resources. It also depends on the way resources are used and distributed throughout the population. If a given environment has a population of 10 individuals, but there is food or drinking water enough for only 9, then in a closed system where no trade is possible, that environment is overpopulated; if the population is 100 but there is enough food, shelter, and water for 200 for the indefinite future, then it is not overpopulated. Overpopulation can result from an increase in births, a decline in mortality rates due to medical advances, from an increase in immigration, or from an unsustainable biome and depletion of resources. It is possible for very sparsely-populated areas to be overpopulated, as the area in question may have a meager or non-existent capability to sustain human life (e.g. the middle of the Sahara Desert).
The resources to be considered when evaluating whether an ecological niche is overpopulated include clean water, clean air, food, shelter, warmth, and other resources necessary to sustain life. If the quality of human life is addressed, there may be additional resources considered, such as medical care, education, proper sewage treatment and waste disposal. Overpopulation places competitive stress on the basic life sustaining resources, leading to a diminished quality of life.
If resources required to sustain the organism are being consumed by the organism faster than the resource can be renewed, then the organism is overpopulated. For example, humans are destroying topsoil and consuming fossil fuels much faster than the planet can renew them and those resources are currently required to produce and distribute the necessary quantity of food to feed the population, and therefore humans are overpopulated on Earth.
Watch now on YouTube: Lecture by Leila Conners Petersen (7 part series)
There is wide variability both in the definition and in the proposed size of the Earth's carrying capacity, with estimates ranging from 1 to 1000 billion. Around two-thirds of the estimates fall in the range of 4 billion to 16 billion (with unspecified standard errors), with a median of about 10 billion.
In a study titled Food, Land, Population and the U.S. Economy, David Pimentel, professor of ecology and agriculture at Cornell University, and Mario Giampietro, senior researcher at the US National Research Institute on Food and Nutrition (INRAN), estimate the maximum US population for a sustainable economy at 200 million. According to this theory, in order to achieve a sustainable economy and avert disaster, the United States would have to reduce its population by at least one-third, and world population would have to be reduced by two-thirds.
Steve Jones, head of the biology department at University College, London, has said, "Humans are 10,000 times more common than we should be, according to the rules of the animal kingdom, and we have agriculture to thank for that. Without farming, the world population would probably have reached half a million by now."
Some groups (for example, the World Wide Fund for Nature and the Global Footprint Network have stated that the carrying capacity for the human population has been exceeded as measured using the ecological footprint. In 2006, WWF's Living Planet report stated that in order for all humans to live with a high degree of luxury (European standards), we would be spending three times more than what the planet can supply. But critics question the simplifications and statistical methods used in calculating ecological footprints. Some point out that a more refined method of assessing ecological footprint is to designate sustainable versus non-sustainable categories of consumption.
David Pimentel, Professor Emeritus at Cornell University, has stated that "With the imbalance growing between population numbers and vital life sustaining resources, humans must actively conserve cropland, freshwater, energy, and biological resources. There is a need to develop renewable energy resources. Humans everywhere must understand that rapid population growth damages the Earth’s resources and diminishes human well-being."
These reflect the comments also of the United States Geological Survey in their paper The Future of Planet Earth: Scientific Challenges in the Coming Century. "As the global population continues to grow...people will place greater and greater demands on the resources of our planet, including mineral and energy resources, open space, water, and plant and animal resources." "Earth's natural wealth: an audit" by New Scientist magazine states that many of the minerals that we use for a variety of products are in danger of running out in the near future. A handful of geologists around the world have calculated the costs of new technologies in terms of the materials they use and the implications of their spreading to the developing world. All agree that the planet's booming population and rising standards of living are set to put unprecedented demands on the materials that only Earth itself can provide. Limitations on how much of these materials is available could even mean that some technologies are not worth pursuing long term.... "Virgin stocks of several metals appear inadequate to sustain the modern 'developed world' quality of life for all of Earth's people under contemporary technology."
On the other hand, some researchers, such as Julian Simon and Bjorn Lomborg believe that resources exist for further population growth. However, critics warn, this will be at a high cost to the Earth: "the technological optimists are probably correct in claiming that overall world food production can be increased substantially over the next few decades...[however] the environmental cost of what Paul R. and Anne H. Ehrlich describe as 'turning the Earth into a giant human feedlot' could be severe. A large expansion of agriculture to provide growing populations with improved diets is likely to lead to further deforestation, loss of species, soil erosion, and pollution from pesticides and fertilizer runoff as farming intensifies and new land is brought into production." Since we are intimately dependent upon the living systems of the Earth, some scientists have questioned the wisdom of further expansion.
According to the Millennium Ecosystem Assessment, a four-year research effort by 1,360 of the world’s leading scientists commissioned to measure the actual value of natural resources to humans and the world, "The structure of the world’s ecosystems changed more rapidly in the second half of the twentieth century than at any time in recorded human history, and virtually all of Earth’s ecosystems have now been significantly transformed through human actions." "Ecosystem services, particularly food production, timber and fisheries, are important for employment and economic activity. Intensive use of ecosystems often produces the greatest short-term advantage, but excessive and unsustainable use can lead to losses in the long term. A country could cut its forests and deplete its fisheries, and this would show only as a positive gain to GDP, despite the loss of capital assets. If the full economic value of ecosystems were taken into account in decision-making, their degradation could be significantly slowed down or even reversed."
Another study by the United Nations Environment Programme (UNEP) called the Global Environment Outlook which involved 1,400 scientists and took five years to prepare comes to similar conclusions. It "found that human consumption had far outstripped available resources. Each person on Earth now requires a third more land to supply his or her needs than the planet can supply." It faults a failure to "respond to or recognise the magnitude of the challenges facing the people and the environment of the planet... 'The systematic destruction of the Earth's natural and nature-based resources has reached a point where the economic viability of economies is being challenged - and where the bill we hand to our children may prove impossible to pay'... The report's authors say its objective is 'not to present a dark and gloomy scenario, but an urgent call to action'. It warns that tackling the problems may affect the vested interests of powerful groups, and that the environment must be moved to the core of decision-making... '
Although all resources, whether mineral or other, are limited on the planet, there is a degree of self-correction whenever a scarcity or high-demand for a particular kind is experienced. For example in 1990 known reserves of many natural resources were higher, and their prices lower, than in 1970, despite higher demand and higher consumption. Whenever a price spike would occur, the market tended to correct itself whether by substituting an equivalent resource or switching to a new technology.
Fresh water supplies, on which agriculture depends, are running low worldwide. This water crisis is only expected to worsen as the population increases. Lester R. Brown of the Earth Policy Institute argues that declining water supplies will have future disastrous consequences for agriculture.
Potential problems with dependence on desalination are reviewed below, however, the majority of the world's freshwater supply is contained in the polar icecaps, and underground river systems accessible through springs and wells.
Fresh water can be obtained from salt water by desalination. For example, Malta derives two thirds of its freshwater by desalination. A number of nuclear powered desalination plants exist, and physicists agree that there are billions of years of nuclear fuel available. But the high costs of desalination, especially for poor countries, make impractical the transport of large amounts of desalinated seawater to interiors of large countries. The cost of desalinization varies; Israel is now desalinating water for a cost of 53 cents per cubic meter, Singapore at 49 cents per cubic meter. In the United Sates, the cost is 81 cents per cubic meter ($3.06 for 1,000 gallons).
According to a 2004 study by Zhoua and Tolb, "one needs to lift the water by 2000 m, or transport it over more than 1600 km to get transport costs equal to the desalination costs. Desalinated water is expensive in places that are both somewhat far from the sea and somewhat high, such as Riyadh and Harare. In other places, the dominant cost is desalination, not transport. This leads to somewhat lower costs in places like Beijing, Bangkok, Zaragoza, Phoenix, and, of course, coastal cities like Tripoli." Thus while the study is generally positive about the technology for affluent areas that are proximate to oceans, it concludes that "Desalinated water may be a solution for some water-stress regions, but not for places that are poor, deep in the interior of a continent, or at high elevation. Unfortunately, that includes some of the places with biggest water problems." Another potential problem with desalination is the byproduction of saline brine, which can be a major cause of marine pollution when dumped back into the oceans at high temperatures."
The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in the United Arab Emirates, which can produce 300 million cubic meters of water per year, or about 2500 gallons per second. The largest desalination plant in the US is the one at Tampa Bay, Florida, which began desalinizing 25 million gallons (95000 m³) of water per day in December 2007. A January 17, 2008, article in the Wall Street Journal states, "Worldwide, 13,080 desalination plants produce more than 12 billion gallons of water a day, according to the International Desalination Association." After being desalinized at Jubail, Saudi Arabia, water is pumped 200 miles (320 km) inland though a pipeline to the capital city of Riyadh.
Studies agree that there is enough food to support the world population, but critics dispute this, particularly if sustainability is taken into account.
More than 100 countries now import wheat and 40 countries import rice. Egypt and Iran rely on imports for 40% of their grain supply. Algeria, Japan, South Korea and Taiwan import 70% or more. Yemen and Israel import more than 90%. And just 6 countries - Argentina, Australia, Canada, France, Thailand and the US - supply 90% of grain exports. In recent decades the US alone supplied almost half of world grain exports.
A 2001 United Nations report says population growth is "the main force driving increases in agricultural demand" but "most recent expert assessments are cautiously optimistic about the ability of global food production to keep up with demand for the foreseeable future (that is to say, until approximately 2030 or 2050)", assuming declining population growth rates.
However, the observed figures for 2007 show an actual increase in absolute numbers of undernourished people in the world, 923 million in 2007 versus 832 million in 1995.;the more recent FAO estimates point out to an even more dramatic increase, to 1.02 billion in 2009.
The amounts of natural resources in this context are not necessarily fixed, and their distribution is not necessarily a zero sum gain. For example, due to the Green Revolution and the fact that more and more land is appropriated each year from wild lands for agricultural purposes, the worldwide production of food had steadily increased up until 1995. World food production per person was considerably higher in 2005 than 1961.
From 1950 to 1984, as the Green Revolution transformed agriculture around the world, grain production increased by over 250%. The world population has grown by about four billion since the beginning of the Green Revolution and most believe that, without the Revolution, there would be greater famine and malnutrition than the UN presently documents.
The number of people who are overweight has surpassed the number who are undernourished. In a 2006 news story, MSNBC reported, "There are an estimated 800 million undernourished people and more than a billion considered overweight worldwide." The US has one of the highest rates of obesity in the world, with 66.5% of the adults over the age of twenty being either obese or overweight.
The Food and Agriculture Organization of the United Nations states in its report The State of Food Insecurity in the World 2006, that while the number of undernourished people in the developing countries has declined by about three million, a smaller proportion of the populations of developing countries is undernourished today than in 1990–92: 17% against 20%. Furthermore, FAO’s projections suggest that the proportion of hungry people in developing countries could be halved from 1990-92 levels to 10% by 2015. The FAO also states "We have emphasized first and foremost that reducing hunger is no longer a question of means in the hands of the global community. The world is richer today than it was ten years ago. There is more food available and still more could be produced without excessive upward pressure on prices. The knowledge and resources to reduce hunger are there. What is lacking is sufficient political will to mobilize those resources to the benefit of the hungry."
As of 2008, the price of grain has increased due to more farming used in biofuels,world oil prices at over $100 a barrel, global population growth, climate change, loss of agricultural land to residential and industrial development, and growing consumer demand in China and India. Food riots have recently taken place in many countries across the world. An epidemic of stem rust on wheat caused by race Ug99 is currently spreading across Africa and into Asia and is causing major concern. A virulent wheat disease could destroy most of the world’s main wheat crops, leaving millions to starve. The fungus has spread from Africa to Iran, and may already be in Afghanistan and Pakistan.
It is becoming increasingly difficult to maintain food security in a world beset by a confluence of "peak" phenomena, namely peak oil, peak water, peak phosphorus, peak grain and peak fish. Growing populations, falling energy sources and food shortages will create the "perfect storm" by 2030, according to the UK government chief scientist. He said food reserves are at a 50-year low but the world requires 50% more energy, food and water by 2030. The world will have to produce 70% more food by 2050 to feed a projected extra 2.3 billion people and as incomes rise, the United Nations' Food and Agriculture Organization (FAO) warned.
We currently have about seven billion people on the planet.The U.N. has a population prospects estimator which is figured to the year 2050. This is a very helpful resource. At current rates of growth, the 2050 population could be nine to eleven billion.
Over-exploitation (or overharvesting) is a distinct ecological term and one of the five main activities threatening global biodiversity. In conservation ecology the term means the taking of biological resources, or organisms, in larger numbers than their populations can withstand.
The phenomenon of over-exploitation resulted in the gradual emergence of the concept of sustainable development and sustainability, which has built on a range of other concepts, e.g. ‘sustainable yield’. ‘eco-development' and ‘deep ecology'.
All living organisms require resources to survive. Over-exploitation of these resources for protracted periods can deplete natural stocks to the point where they are unable to recover within a short time frame. Expanding markets and increasing demand, combined with improved access and techniques for capture, are causing the exploitation of many species beyond sustainable levels. In practical terms, if continued, it reduces valuable resources to such low levels that their exploitation is no longer sustainable and can lead to the extinction of a species, in addition to having dramatic, unforeseen effects, on the ecosystem.
Examples:
Overall, 50 bird species that have become extinct since 1500 (approximately 40% of the total) have been subject to over-exploitation, including:
Great Auk- The penguin of the north, hunted for its feathers, meat, fat and oil.
Carolina Parakeet - The only parot species native to the eastern United States, was hunted for crop protection.
Reversal:
Sea Otter
During the 18th and 19th centuries, the sea otter was heavily exploited, prized universally for its exceptionally warm and tremendously valuable pelt, which could fetch a price of between $2000 – $2500 US dollars. Fur traders hunted the sea otters so intensively for their skins, that they were exterminated over huge areas. Their disappearance led to dramatic changes in the environment. Sea urchins, with no otters to control their numbers, increased explosively. Urchins eat kelp and they began to destroy the underwater forests. As the kelp disappeared, so did the other animals that relied upon it. Soon all that was left was a bare seabed carpeted with urchins.
One small group of 32 individuals survived in a remote cove and hunting the sea otters was eventually banned. Under heavy protection, those 32 multiplied to 2,377 repopulating the depleted areas, which eventually made a full recovery.
In addition, with declining numbers of fish stocks, again due to over-exploitation, killer whales have experienced a food shortage and have been observed feeding on Sea otters, again reducing their numbers.
We must use our natural resources efficiently, humanely and sustainably. We must transition from the use of nonrenewable energy resources such as fossil fuels (petroleum, coal, natural gas), to renewable resources such as solar, wind energy, hydroelectric, micro-hydro, geothermal, wave and tidal power. Our policies must be designed for the long term, not merely short term corporate gain. Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFC's and nitrous oxide. The concentrations of CO2 and methane have increased by 36% and 148% respectively since 1750. These levels are much higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. Less direct geological evidence indicates that CO2 values this high were last seen about 20 million years ago. Fossil fuel burning has produced about three-quarters of the increase in CO2 from human activity over the past 20 years. Most of the rest is due to land-use change, particularly deforestation. CO2 concentrations are continuing to rise due to burning of fossil fuels and land-use change. The future rate of rise will depend on uncertain economic, sociological, technological, and natural developments. Accordingly, the IPCC Special Report on Emissions Scenarios gives a wide range of future CO2 scenarios, ranging from 541 to 970 ppm by the year 2100 (an increase by 90-250% since 1750). Fossil fuel reserves are sufficient to reach these levels and continue emissions past 2100 if coal, tar sands or methane clathrates are extensively exploited. The IPCC does not carry out its own original research, nor does it do the work of monitoring climate or related phenomena itself. A main activity of the IPCC is publishing special reports on topics relevant to the implementation of the UN Framework Convention on Climate Change (UNFCCC), an international treaty that acknowledges the possibility of harmful climate change. Implementation of the UNFCCC led eventually to the Kyoto Protocol. The IPCC bases its assessment mainly on peer reviewed and published scientific literature. The IPCC is only open to member states of the WMO and UNEP. IPCC reports are widely cited in almost any debate related to climate change. National and international responses to climate change generally regard the UN climate panel as authoritative. The summary reports (i.e. Summary for Policymakers), which draw the most media attention, include review by participating governments in addition to scientific review. The Millennium Ecosystem Assessment (MA) was called for by the United Nations Secretary-General Kofi Annan in 2000. Initiated in 2001, the objective of the MA was to assess the consequences of ecosystem change for human well-being and the scientific basis for action needed to enhance the conservation and sustainable use of those systems and their contribution to human well-being. The MA has involved the work of more than 1,360 experts worldwide. Their findings, contained in five technical volumes and six synthesis reports, provide a state-of-the-art scientific appraisal of the condition and trends in the world’s ecosystems and the services they provide (such as clean water, food, forest products, flood control, and natural resources) and the options to restore, conserve or enhance the sustainable use of ecosystems. The bottom line of the MA findings is that human actions are depleting Earth’s natural capital, putting such strain on the environment that the ability of the planet’s ecosystems to sustain future generations can no longer be taken for granted. At the same time, the assessment shows that with appropriate actions it is possible to reverse the degradation of many ecosystem services over the next 50 years, but the changes in policy and practice required are substantial and not currently underway. Watch now on YouTube: Blue Man Group on Global Warming
Peak Oil Technology - an excellent website for more information
The future New York City skyline.
Watch now on YouTube: Global Warming 101
The Reality of Global Warming
Global Warming Explained in 10 Minutes, by Al Gore
Global Warming: Facts and Solution
The Assault on Reason, a speech by Al Gore
Human activity is the primary cause of Global Warming
Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) between the start and the end of the 20th century. The Intergovernmental Panel on Climate Change (IPCC) concludes that most of the observed temperature increase since the middle of the 20th century was caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation. The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanism produced most of the warming from pre-industrial times to 1950 and had a small cooling effect afterward These basic conclusions have been endorsed by more than 40 scientific societies and academies of science, including all of the National Academies of Science of the major industrialized countries.
The Earth’s climate is projected to change because human activities are altering the chemical composition of the atmosphere through the build-up of greenhouse gases- primarily carbon dioxide, methane and nitrous oxide. These gases trap heat and create a rise in global temperature.
The effect of the potential rise in surface temperature would be to speed up the hydrological cycle. Increases of 4 to 7 percent in the global mean evaporation and precipitation rates might occur for a doubling of the carbon dioxide level and a few degrees rise in global mean temperature. The effect on the water balance would be regional in nature, with some places becoming wetter and others drier. In general, there would be a trend toward greater and longer periods of summer dryness induced by lower soil moisture content and higher evaporation rates in the mid-latitudes of the Northern Hemisphere.
The potential changes in the hydrologic cycle do not seem great. However, their consequences could be severe for ecosystems and human populations, notably since the latter are so sensitive to and dependent on such changes.
On the other hand, there could be benefits and opportunities in some regions as the climate changes. In the Arctic, for example, as warming occurs, there will be more running and standing water, along with a thinner and reduced ice cover. Coastal navigation will increase with new opportunities for water transport, tourism and trade. The Arctic Ocean could become a major global trade route. Also, some northern extension of farming may be possible, and in general, marine ecological activity should rise.
What is the Intergovernmental Panel on Climate Change (IPCC)?
The Intergovernmental Panel on Climate Change (IPCC) is a scientific intergovernmental body tasked with evaluating the risk of climate change caused by human activity. The panel was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), two organizations of the United Nations. The IPCC shared the 2007 Nobel Peace Prize with former Vice President of the United States, Al Gore.
For more info on the IPCC, click here.
For the IPCC Website, click here.
What is the Millennium Ecosystem Assessment (MA)? What are the main findings of the MA?
Free downloadable figures, tables, maps, data, posters, logos and brochures from the Millennium Ecosystem Assessment are available here.
What is the objective of the Kyoto Protocol?
Watch now on YouTube: The Kyoto Protocol Video
The objective of the Kyoto Protocol is the "stabilization and reconstruction of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system."
The objective of the Kyoto climate change conference was to establish a legally binding international agreement, whereby all the participating nations commit themselves to tackling the issue of global warming and greenhouse gas emissions. The target agreed upon was an average reduction of 5.2% from 1990 levels by the year 2012. Contrary to popular belief, the Protocol will NOT expire in 2012. In 2012, Annex I countries must have fulfilled their obligations of reduction of greenhouse gases emissions established for the first commitment period (2008–2012) (see Annex B of the Protocol).
Proponents also note that Kyoto is a first step as requirements to meet the UNFCCC will be modified until the objective is met, as required by UNFCCC Article 4.2(d).
The five principal concepts of the Kyoto Protocol are:
Award-Winning Animation on Global Warming
What is GLOBIO?
GLOBIO (Global Methodology for Mapping Human Impacts on the Biosphere) was initiated to provide an inexpensive, simple scientifically based communication tool for mapping, at large scale, the likelihood of human impacts on the biosphere resulting from increasing growth in resource utilization. GLOBIO is intended to bring scientific evidence on human impacts into a format suitable for policymaking.
More information is available at the Globio website here. Rant & Reason: Humanist Perspectives on News about the environment
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