Ek plaas die volgende uittreksels oor bostaande onderwerp en sal later poog om meer inligting te kry, veral oor waterbeskikbaarheid.
Die eerste is uit The Guardian, Verenigde Koninkryk-uitgawe. Ek het ongelukkig nie die datum nie.
Marianela Fader from the Potsdam Institute for Climate Impact Research, Germany, and colleagues, calculated the growing capacity of every country in the world, and compared it with food requirements, both now and projected forward to 2050. Their model employed climate data, soil type and land-use patterns for each country, in order to simulate yields for a variety of types of crop. Using current data on population, and food and water consumption in each nation, they were able to assess what proportion of its food a country could produce.
Although many countries choose to import food right now, the model showed that there are surprisingly few that could not maintain the same diet and still be food self-sufficient. "Today, 66 countries are not able to be self-sufficient due to water and/or land constraints," said Fader. This equates to 16% of the world's population depending on food imported from other countries.
The countries with the most reliance on imports were found in North Africa, the Middle East and Central America, with over half the population depending on imported food in many of these locations. Outside those locations many countries could become food self-sufficient if they chose to.
But roll the clock forward to 2050 and population pressure paints a very different picture. Vast swathes of the global map are coloured red and orange, highlighting those countries that would have to maximize food production – by improving agricultural productivity, and expanding cropland, for example – in order to feed their population. The figures suggest that over half the world's population could depend on imported food by 2050.
"Assuming that all low-income economies achieve full potential productivity by 2050 in addition to full cropland expansion – which would be a huge societal and technological challenge and thus a very optimistic assumption – the food self-sufficiency gap will still be equivalent to about 55–123 million people, with over 20 million in Niger and Somalia alone," explained Fader, whose findings are published in Environmental Research Letters. Add on the impact of climate change – not included in this study – and the problem could be even more severe.
A number of developed countries, including the UK, the Netherlands and Japan, are already unable to meet the food requirements of their populations. This reliance on imports looks set to become worse as population levels rise. However, unlike the developing countries, these nations will probably be able to buy their way out of the problem.
Food security is going to be a big issue over the coming decades. The study indicates that improving agricultural productivity can play a key role in maintaining food security. Meanwhile, a change in diet, such as towards more seasonal and vegetarian food, could also have a significant impact, although this is not explored in the current work.
Die volgende is uit Wikipedia, onder die hofie "World Population":
From 1950 to 1984, as the Green Revolution transformed agriculture around the world, grain production increased by over 250%.[112] The world population has grown by about four billion since the beginning of the Green Revolution, and most scholars believe that, without the Revolution, there would be greater levels of famine and malnutrition than the UN presently documents.[113] The energy for the Green Revolution was provided by fossil fuels, in the form of natural gas-derived fertilizers, oil-derived pesticides, and hydrocarbon-fueled irrigation.
The potential peaking of world oil production may test the critics of Malthus and Ehrlich, as oil is of crucial importance to global transportation, power generation and agriculture.[114] In May 2008, the price of grain was pushed up severely by the increased cultivation of biofuels, the increase of world oil prices to over $140 per barrel ($880/m3),[115] global population growth,[116] the effects of climate change,[117] the loss of agricultural land to residential and industrial development,[118][119] and growing consumer demand in the population centres of China and India.[120][121] Food riots subsequently occurred in some countries.[122][123] However, oil prices then fell sharply, and remained below $100/barrel until around 2010. Resource demands are expected to ease as population growth declines, but it is unclear whether mass food wastage and rising living standards in developing countries will once again create resource shortages.[124][125]
Richard C. Duncan claims that the world population will decline to about 2 billion around 2050.[126] David Pimentel, professor of ecology and agriculture at Cornell University, estimates that the sustainable agricultural carrying capacity for the United States is about 200 million people; its population as of 2013 is over 310 million.[127] In 2009, the UK government's chief scientific advisor, Professor John Beddington, warned that growing populations, falling energy reserves and food shortages would create a "perfect storm" by 2030. Beddington claimed that food reserves were at a fifty-year low, and that the world would require 50% more energy, food and water by 2030.[128][129] According to a 2009 report by the United Nations Food and Agriculture Organisation (FAO), the world will have to produce 70% more food by 2050 to feed a projected extra 2.3 billion people.[130]
The observed figures for 2007 showed an actual increase in absolute numbers of undernourished people in the world, with 923 million undernourished in 2007, versus 832 million in 1995.[131] The 2009 FAO estimates showed an even more dramatic increase, to 1.02 billion.[132]
Environmental impacts
A number of scientists have argued that the current global population expansion and accompanying increase in resource consumption threatens the world's ecosystem, as well as straining humanity's ability to feed itself.[133][134] The InterAcademy Panel Statement on Population Growth, which was ratified by 58 member national academies in 1994, called the growth in human numbers "unprecedented", and stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, and pollution, were aggravated by the population expansion.[135] Indeed, some analysts claim that overpopulation's most serious impact is its effect on the environment.[13] At the time of the 1994 IAP statement, the world population stood at 5.5 billion, and lower-bound scenarios predicted a peak of 7.8 billion by 2050, a number that current estimates state will be reached in the late 2020s.
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Kennis geneem baie dankie daarvoor van my kant af ook.