FORGET CLIMATE CHANGE: MEGAFAUNA EXTINCTION DUE TO HUMAN OVERKILL, ECONOMISTS CLAIM

(From Journal of Economic Behavior & Organization, Article in Press)

Megafauna extinction: A paleoeconomic theory of human overkill in the pleistocene

By: Erwin Bulte a), Richard D. Horan b), and Jason F. Shogren c), a) Department of Economics, Tilburg University, P.O. Box 90153, 5000 LE Tilburg, The Netherlands b) Department of Agricultural Economics, Michigan State University, East Lansing, MI 48824-1039, USA c) Department of Economics and Finance, University of Wyoming, Laramie 82071, USA

Abstract

After centuries of debate, paleontologists are converging towards the conclusion that human overkill caused the massive extinction of large mammals in the late Pleistocene. This paper revisits the question of megafauna extinction by incorporating economic behavior into the debate. We allow for endogenous human population growth, and labor allocation decisions involving activities such as wildlife harvesting and (proto) agriculture. We find that the role of agriculture in deciding the fate of megafauna was small. In contrast, the presence of ordinary small animals that have been overlooked in previous non-economic extinction models is likely to have been much more important.

1. Introduction

About 12,000 years ago one of the great scientific mysteries occurred. Up until that time, during the first 2 million years of the Pleistocene, species rarely went extinct. In the Americas, for instance, fifty species of large mammals went extinct, an average of 1 every 40,000 years. But then around 12,000 years ago something changed, and over the next 2000 years, species extinction exploded. The Americas lost 57 large mammals, including three genera of elephants, in this short time span, an average rate of 1 every 30 years. Megafauna such as mammoths, mastodons, giant ground sloth, and Deinotherium disappeared, and many agile species like horses and camels went extinct locally.

Centuries of debate within the palaeontology community over megafauna extinction have produced two competing theories, climate change versus human overkill. The climate change view argues that megafauna extinction occurred because large species were slower to adapt to advancing and retreating ice sheets than the plant communities upon which they grazed. The plants adapted relatively quickly to abrupt climate change; the large mammals did not, hence, their exit.

1. The theory of human overkill counters it was early man with his limited technology, not climate that created havoc in the natural world. In the Americas, for instance, evidence suggests the small bands of Clovis people crossed the Bering land bridge from Asia about 12,000 years ago.

2. The fact that species began to disappear abruptly at the same time, so the argument goes, was no coincidence. Some fossil evidence exists to support the view that skilful hunters preyed on large mammals that did not adapt to their new and aggressive predator.

3. Many natural scientists believe it is essential to understand today whether it was climate or primitive man that caused the megafaunal collapse. Such knowledge provides a history lesson on what might happen in the future if we do not address modern risks of climate change and overpopulation (see, e.g., Leakey and Lewin, 1995), but at least until recent times, progress in understanding what happened has been hampered by an identification problem.

In North America, megafauna extinction occurred both when man first appeared and during a violent phase of climate change. Both forces hit the megafauna simultaneously, and the fossil record has provided little help in differentiating between the hypotheses due to the simultaneity issue and poor quality fossil data. Two recent well-publicized studies examining extinctions in Australia and in the Americas, however, point to human overkill as the culprit. For Australia, Roberts et al. (2001) found the continent-wide extinction did not coincide with extreme climatic events, implicating overkill as the most likely explanation. For North America, the paleontologist Alroy (2001) followed others who have used mathematical simulation to explore the plausibility of the theories (e.g., Mosimann and Martin, 1975 and Whittington and Dyke, 1984). Using a model that was much richer in ecological detail than prior analyses (e.g., he distinguishes between 41 herbivore species rather than one aggregate stock) and relaxing some restrictive assumptions that had been made by others (e.g., constant human population growth rates), Alroy points to overkill as the culprit.

Although these studies have not ended the debate over climate change versus overkill (e.g., Brook and Bowman, 2002 and Stuart, 2005), they do suggest growing support within the paleontological profession for the theory that, at least in North America and Australia, human overkill is responsible for large-scale extinction of megafauna. But the overkill explanation raises an important set of new questions. If overkill was the cause, why did it happen? And what economic behavioral mechanisms could have driven this result?

Unfortunately, these paleontological models cannot address these questions because they lack a realistic behavioral component. Rather these models tend to be "fully mechanistic," with humans as "super predators" who spend their time either hunting or procreating. More specifically, these paleontological simulation models focus exclusively on megafauna hunting and do not address the broader opportunity set and the behavioral tradeoffs facing households in the late Pleistocene. In effect, these models sidestep Smith's (1975) durable point that the separation of man and nature does not address primitive man's labor allocation decisions (for example, whether to hunt megafauna or spend time in other activities), and this choice could affect the degree to which overkill played a role (see also Shogren and Crocker (1999) on the issue of nature and economics being jointly determined). Smith argues, and we agree, that explicit economic behavior should be considered "to demonstrate the use of a coherent economic framework for the study and evaluation of extinction or other hypotheses concerning the primitive hunter culture" (1975, p. 750).

This paper explores the plausibility of the overkill hypothesis and examines the economic mechanisms that might support this hypothesis. Overkill is only consistent with megafauna collapse and human survival if humans have access to a substitute food source (i.e., an outside option). Otherwise, humans would die after the megafauna go extinct. Smith (1975) suggests agriculture provided the substitute food source and was the impetus of megafauna extinction. But this theory has yet to be tested in a model with endogenous human population growth, and a numerical analysis has never been performed to examine the robustness of the theory. Extending Smith (1975), we develop and calibrate a paleoeconomic model allowing for endogenous growth of both animal and human populations (see Nerlove, 1993), in which a hunter allocates his labor between alternative uses given an endogenous species kill rate.

4. We find that Smith's case for early agriculture can be challenged as the likely explanation for megafauna extinction. Such proto agriculture may let the human population grow faster, which could increase hunting pressure on megafauna, but a competing opportunity cost effect emerges because the ability to subsist from plant-based food increases the opportunity cost of hunting for scarce animals, certainly when animal stocks are small and catch per unit of effort is low. By introducing a lower bound on the opportunity cost of hunting effort, agriculture could decrease the likelihood of megafauna extinction. Our numerical results indicate the opportunity cost effect was likely sufficiently strong to avoid megafauna collapse, which does not support agriculture as the cause of extinction. If agriculture was not the cause, what was?

We propose the cause was a second alternative food source, small animals or "mini-fauna." As people allocate more effort to hunting minifauna, more opportunities for chance encounters with megafauna arise, which leads to more megafauna harvests. In contrast, if labor is devoted to agriculture, opportunities for chance encounters decrease. Hunting minifauna is a complementary activity for megafauna harvests, whereas agriculture is a substitute activity. Moreover, if overkill occurs in the presence of a steady supply of substitute prey, mainly the small and ordinary animals living today, these minifauna could have supported human population growth when megafauna became scarce. Small and rapidly replenishing animals such as deer can support an expanding human population, even as megafauna densities fell. The incidental killing of megafauna continued until extinction occurred, and humans moved on.

While our results support Alroy's mechanistic findings that many smaller animals survived while the larger ones were killed off, our behavioral model captures endogenous feedbacks between the economic and natural system and triggers results that point directly at humans as the culprits of megafauna extinction....

Doi (permanent) address for the above paper here





GOVERNMENTS ARE AFRICA'S PROBLEM: NOT GLOBAL WARMING

Wood and dung are the primary sources of energy in Kenya and much of Africa - providing heat for the home and cooking. Clean fuels such as natural gas and electricity, not to mention central heating and air-conditioning, are luxuries reserved for plutocrats, politicians, and NGOs.

Why do so many Africans rely on dirty energy sources? For the same reason that they are poor: their oppressive governments prevent them engaging in mutually beneficial economic activities. It is illegal in most African states to start a business without a licence. And licences are available only to those with government connections. Even if it were possible legally to operate a business, few would have the necessary capital. While their governments have been borrowing as if there were no tomorrow, most Africans cannot obtain a loan at any reasonable rate of interest. Those same oppressive, corrupt and incompetent governments prevent them obtaining good title to their land and thus they have nothing to offer as collateral. So instead of creating wealth through private enterprise, many of Africa's entrepreneurs hawk in the streets or engage in criminal acts.

Among the worst criminals are the leaders to whom we have given massive amounts of 'aid'. Thugs such as Mobutu, Abacha and Mugabe bought themselves cars, planes and palaces - and stashed cash in offshore bank accounts. Ostensibly given to enable poor countries to escape from the poverty 'trap', aid has actually harmed the poor by sustaining oppressive dictators.

Now, Blair and Brown, the 'Lennon and McCartney of global development', think that poverty can be solved by spending another $25 billion in Africa every year until 2015. Some chance. One reason that aid has failed dismally is that it was used to support foreign policy objectives. During the Cold War both the US and the USSR used it to bolster 'friendly' regimes. Although many of those regimes' leaders were repressive, undemocratic and hostile to free enterprise, the US continued to send tens of billions of dollars, ostensibly to support liberty, democracy and free markets!

Since the end of the Cold War, the foreign-aid carrot has been used to encourage governments of poor countries to endorse foreign policy agendas such as environmental protection. Before the 1992 Earth summit in Rio, wealthy countries offered poor countries billions of dollars in return for commitments to sign treaties on climate change, biodiversity, forests and 'sustainable development'. African leaders even got their own treaty, the UN Convention to Combat Desertification - which contains numerous references to increasing aid to Africa (but will do nothing to halt land degradation).

As the Kyoto Protocol runs out of steam, an aid carrot is being offered to poor countries in exchange for commitments to future reductions in greenhouse gas emissions. Yet attempting to control the climate through such restrictions may prove counterproductive. Meanwhile, this aid carrot will probably do more harm than good.

Dramatic warming is unlikely to result from humanity's emissions in the next century. The best estimates suggest a moderate warming of between one and two degrees Celsius - a change that may even be beneficial. In a slightly warmer world with more carbon dioxide, agricultural output would increase, and more food would be available at a lower cost. Climate change may nevertheless cause some problems. For example, changing rainfall patterns might affect agriculture. While wealthy countries have increasingly sophisticated systems of water management, which enable us to cope with such changes, the situation in poor countries is more problematic.

At present, government control of water leads to massively inefficient overuse. Privatising water would force consumers and producers to pay prices that reflect delivery costs, thus providing incentives to use water more rationally and encouraging new methods of production and delivery - such as piping water over longer distances or desalinating seawater. Government mismanagement and corruption also mean that today over one billion people lack access to clean drinking water.

A Kenyan colleague moved to Nairobi in 2001 to start a think-tank. Soon afterwards, local government officials visited his house and issued a water bill, which he diligently paid. A few days later the same officials returned, demanding that he pay, again. In spite of paying twice, his water is erratic and contaminated. In Chile, water supply was privatised in 1981 and the proportion of households with clean, piped water soon shot up from 63 to 99 per cent in towns, and from 27 to 94 per cent in rural areas. Many other countries have followed suit. This week a group going by the name of 'People without Water' in Lima, Peru, called for their water to be privatised because they realise that the private sector is more accountable, less corrupt and more likely to deliver. By increasing the availability of potable water, privatisation would greatly reduce the number of deaths from water-borne diseases, such as diarrhoea and cholera, which now kill about two million children each year.

But cleaning and piping water requires energy. Imposing emissions restrictions would increase the cost of energy because suppliers would be forced to use more expensive, lower-carbon energy sources. As a result, the cost of water would increase.

Likewise, the cost of producing, refrigerating and transporting food and medicines would rise, reducing the availability of these vital goods. If clean energy sources such as natural gas and electricity are made more costly, Africans will continue to burn inefficient, dirty fuels such as wood and dung. Though such fuels may be 'renewable' and 'low-carbon', their combustion in poorly flued indoor fires contributes heavily to acute lower respiratory infections, such as pneumonia and tuberculosis, which today kill more than one million children annually.

To enable development and adaptation to the current climate, let alone any future climate, Africans must be freed from oppressive governments. Emissions restrictions would hinder that adaptation process, especially if such restrictions are encouraged with 'aid' to their governments. These observations cast doubt on Blair's priorities for the G8 meeting - and the process of priority-setting for G8 meetings generally. Blair wants to be the great global statesman who saved Africa from poverty and the world from climate change, but these problems are not based on a rational assessment of global priorities.

Of all the plans on the table, Gordon Brown's proposal to provide funds to buy new medicines for Aids and malaria is perhaps the most sane. Crucially, the money will not go to corrupt African leaders. In 2004, under the auspices of the Copenhagen Consensus, a group of eminent academics concluded that eradicating communicable diseases, improving access to clean water and freeing trade would provide the greatest benefit for the world's people. By contrast, they ranked reductions in greenhouse gas emissions an extremely bad investment. Perhaps the G8 should conduct its own Copenhagen Consensus for next year's agenda.

Source






PROF. STOTT REWRITES A BBC DOOM AND GLOOM REPORT WITH A DIFFERENT SPIN:

(The BBC was horrified that "Fields of sunflowers could replace the traditional English landscape" One's heart bleeds!)

The English garden in the South East is due for a new blaze of colour because of global warming, experts say.

By Persephone Polyanna

The English country gardener in the South East will be presented with many new opportunities for planting in the next 100 years, scientists say. Climate change might, though we don't know, reduce our need to maintain large lawns and help us to diversify the shrub borders of Surrey, Kent, Hampshire, and Sussex. We may even be able to develop fair olive groves and extend grape vines. The benefits of possible 'global warming' are being discussed today at a The Royal Society for Happy Gardeners (RSHG) conference at the University of Wisley.

Following certain selected climate scenarios (which, however, are only computer-based) experts say summer temperatures in the South East may hopefully rise by up to 1.5C by 2050, although the effect on rainfall is not certain.

With a bit of luck - although again we have no idea - it might even be a little warmer still by the 2080s, the scientists say. "This is going to provide truly exciting opportunities for the gardener", said Penelope Poppy from the RSHG. "It's already happening - you can see fields of smiling sunflowers everywhere", grins Professor Bob Bloomer, holding up some striking lavender cultivars.

"For the average gardener there will be lots of terrific new colourful plants to choose from, while the National Trust will find it easier to maintain some of the more expensive exotic gardens and orangeries from the Victorian and Edwardian Ages. Less fuel will be needed to service greenhouses and glasshouses, and this can only be good for the environment."

"And don't we just love the paintings of Vincent Van Gogh!" Penelope Poppy purrs. "We may well be able to have parts of England recalling the gorgeous Mediterranean scenes painted by Vincent and by Bonnard, with fields of sunflowers becoming common features along with palms, shrubs, and gorgeous-smelling eucalyptus! I can't wait! Sounds like natural aromatherapy everywhere."

One possible pity is that levels of sunlight tend to be lower in England than in the Med, but many plant and tree species found in southern France are still expected to become more common further north, again providing an increase in biodiversity and gardening choice. These will include the walnut, poplar, sweet chestnut, plums, kiwi fruits, pistachio trees, and vines, the scientists say. Our native woodlands of oak, beech, ash and Scots pine will survive, just increasing the new overall biodiversity, though we might lose a few beeches in Kent and Surrey.

Overall this is a wonderful opportunity. "If, of course, it happens", cautions Prof. Bloomer. "We may start to cool, and that could be quite challenging for gardeners."

(The Stott version is from here)

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Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is to promote themselves as wiser and better than everyone else, truth regardless.

Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists

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