Friday, November 30, 2012
Understanding the problem of fresh water scarcity begins by considering the distribution of water on the planet. Approximately 98% of our water is salty and only 2% is fresh. Of that 2%, almost 70% is snow and ice, 30% is groundwater, less than 0.5% is surface water (lakes, rivers, etc) and less than 0.05% is in the atmosphere. Climate change has several effects on these proportions on a global scale. The main one is that warming causes polar ice to melt into the sea, which turns fresh water into sea water, although this has little direct effect on water supply.
Another effect of warming is to increase the amount of water that the atmosphere can hold, which in turn can lead to more and heavier rainfall when the air cools. Although more rainfall can add to fresh water resources, heavier rainfall leads to more rapid movement of water from the atmosphere back to the oceans, reducing our ability to store and use it. Warmer air also means that snowfall is replaced by rainfall and evaporation rates tend to increase. Yet another impact of higher temperatures is the melting of inland glaciers. This will increase water supply to rivers and lakes in the short to medium term, but this will cease once these glaciers have melted. In the sub-tropics, climate change is likely to lead to reduced rainfall in what are already dry regions. The overall effect is an intensification of the water cycle that causes more extreme floods and droughts globally.
When planning future water supplies, however, the global picture is less important than the effect of warming on fresh water availability in individual regions and in individual seasons. This is a much more complicated thing to predict than global trends. The IPCC technical report on climate change and water concludes that, despite global increases in rainfall, many dry regions including the Mediterranean and southern Africa will suffer badly from reduced rainfall and increased evaporation. As a result, the IPCC special report on climate change adaptation estimates that around one billion people in dry regions may face increasing water scarcity.
However, the degree to which this will happen cannot be predicted with confidence by current models. In many regions different models cannot even agree on whether the climate will become wetter or drier. For example, a recent study of future flows in the River Thames at Kingston shows a possible 11% increase over the next 80 years relative to the last 60 years. However, under an identical emissions scenario, the same report shows an alternative projection of a 7% decrease in flows.
Especially little is known about future declines in regional groundwater resources because of lack of research on this topic, even though around 50% of global domestic water supply comes from groundwater. Although scientists are making progress in reducing uncertainty about fresh water scarcity, these kinds of unknowns mean that water supply strategies must be adaptable so that they can be effective under different scenarios.
The direct impact of climate change is not the only reason to be concerned about future fresh water scarcity – a fact highlighted by a recent United Nations Environment Programme report. The increasing global population means more demand for agriculture, greater use of water for irrigation and more water pollution. In parallel, rising affluence in some countries means a larger number of people living water-intensive lifestyles, including watering of gardens, cleaning cars and using washing machines and dishwashers. Rapidly developing economies also result in more industry and in many cases this comes without modern technology for water saving and pollution control. Therefore concerns about climate change must be viewed alongside management of pollution and demand for water.
The most common solution to increasing demand, and a way of insuring against possible climate change impacts, is the engineered redistribution of freshwater over space and time: reservoirs to store it, pipelines to transfer it, and desalination to recover freshwater from the oceans. Efforts are also being made to increase water saving, reuse and recycling, and in the UK there is currently major investment into education and water-saving technology by the government and water industry. More
Thursday, November 29, 2012
BALBALA, 27 November 2012 (IRIN) - Successive years of poor rains have eroded the coping mechanisms of pastoralists in Djibouti’s rural regions, even as high food prices and unemployment rates afflict the country’s urban areas. These factors are increasing the vulnerability to food insecurity and spurring migration.
|Checking for malnutrition in Balbala|
Farah says that back in Ali Sabieh, residents are moving closer to the Ali Addeh refugee camp, hoping to obtain some of the assistance meant for the camp’s 16,778 refugees. “I don’t know how they are getting along. What we need most is food,” he said.
|Today, I left at 4am to go and look for work and came back home with nothing. There are days when we eat nothing|
Monday, November 19, 2012
Over the last several decades, as demand for fish and shellfish for food, feed, and other products rose dramatically, fishing operations have used increasingly sophisticated technologies—such as on-vessel refrigeration and processing facilities, spotter planes, and GPS satellites. Industrial fishing fleets initially targeted the northern hemisphere’s coastal fish stocks, then as stocks were depleted they expanded progressively southward on average close to one degree of latitude annually since 1950. The fastest expansion was during the 1980s and early 1990s. Thereafter, the only frontiers remaining were the high seas, the hard-to-reach waters near Antarctica and in the Arctic, and the depths of the oceans.
The escalating pursuit of fish—now with gross revenue exceeding $80 billion per year—has had heavy ecological consequences, including the alteration of marine food webs via a massive reduction in the populations of larger, longer-lived predatory fish such as tunas, cods, and marlins. Unselective fishing gear, including longlines and bottom-scraping trawls, kill large numbers of non-target animals like sea turtles, sharks, and corals.
As of 2009, some 57 percent of the oceanic fish stocks evaluated by FAO are “fully exploited,” with harvest levels at or near what fisheries scientists call maximum sustainable yield (MSY). If we think of a fish stock as a savings account, fishing at MSY is theoretically similar to withdrawing only the accrued interest, avoiding dipping into the principal.
Some 30 percent of stocks are “overexploited”—they have been fished beyond MSY and require strong management intervention in order to rebuild. The share of stocks in this category has tripled since the mid-1970s. A well-known example of this is the Newfoundland cod fishery that collapsed in the early 1990s and has yet to recover.
This leaves just 13 percent of oceanic fish stocks in the “non-fully exploited” category, down from 40 percent in 1974. Unfortunately, these remaining stocks tend to have very limited potential for safely increasing the catch.
These FAO figures describe 395 fisheries that account for some 70 percent of the global catch. Included are the small minority that have undergone the time-consuming and expensive process of formal scientific stock assessment, with the remainder being "unassessed" fisheries. There are thousands more unassessed fisheries, however, that are absent from the FAO analysis. In a 2012 Science article, Christopher Costello and colleagues published the first attempt to characterize all of the world’s unassessed fisheries. The authors report that 64 percent of them were overexploited as of 2009.
The top 10 fished species represent roughly one quarter of the world catch. Nearly all of the stocks of these species are considered fully exploited (most of these fish have more than one geographically distinct stock), including both of the major stocks of Peruvian anchovy, the world's leading wild-caught fish. Stocks that are overexploited and in need of rebuilding include largehead hairtail—a ribbon-like predator caught mainly by Chinese ships—in its main fishing grounds in the Northwest Pacific. (See data.)
Despite the unsustainable nature of current harvest levels, countries continue to subsidize fishing fleets in ways that encourage even higher catches. Governments around the world spend an estimated $16 billion annually on increasing fleet size and fish-catching ability, including $4 billion for fuel subsidies. Industrial countries spend some $10 billion of that total. More than $2 billion is spent by China, whose 15-million-ton catch is nearly triple that of the next closest country, Indonesia. More
Wednesday, November 7, 2012
- There will be 219,000 people at the dinner table tonight who were not there last night—many of them with empty plates.
- As a result of chronic hunger, 48 percent of all children in India are undersized, underweight, and likely to have IQs that are on average 10-15 points lower than those of well-nourished children.
- Food prices are rising dramatically. The U.N. Food Price Index in June 2012 was twice the base level of 2002-04.
- More than half the world’s people live in countries where water tables are falling as aquifers are being depleted.
- A startling 80 percent of oceanic fisheries are being fished at or beyond their sustainable yield.
- Between 2005 and 2011, the amount of grain used to produce fuel for cars in the United States climbed from 41 million to 127 million tons—nearly a third of the U.S. grain harvest.
- In 2011, China consumed 70 million tons of soybeans, 56 million of which had to be imported. Almost all went into livestock feed.
- Today, with incomes rising fast in emerging economies, there are at least 3 billion people moving up the food chain, consuming more grain-intensive livestock and poultry products.
- Data for India indicate that 175 million people are being fed with grain produced by overpumping. For China, there are 130 million in the same boat.
- In Ethiopia, a prime target for foreign land acquisitions yet also a major food aid recipient, an acre of land can be leased for less than $1 per year.
- The 464 land acquisitions identified by the World Bank in 2010 totaled some 140 million acres—more than is planted in corn and wheat combined in the United States.
- It’s not all bad news: 44 countries have reached population stability as a result of gradual fertility decline over the last several generations.
Full Planet, Empty Plates: The New Geopolitics of Food Scarcity is available for purchase online. Get a sneak peek by checking out Chapter 1: Food the Weak Link or watch the five minute video below and hear from Lester Brown himself about the main issues raised in the book.
Sunday, November 4, 2012
Recalibrating Food Production in the Developing World: Global Warming Will Change More Than Just the Climate
An analysis of the effects of climate change on 22 critical agricultural commodities and three important natural resources in the developing world reveals a number of cross-cutting themes: The world’s agricultural systems face an uphill struggle in feeding a projected nine to ten billion people by 2050. Climate change introduces a significant hurdle in this struggle.
- Securing and maintaining necessary levels of calories, protein and nutrients for populations around the world will be an exceptional challenge.
- Recalibrating agriculture in the face of climate change is more than planting crops that can tolerate warmer weather. Some commodities, for example, can grow in warm weather but cannot resist the insects and diseases whose prevalence will increase. Others can tolerate
a lack of water but not the sporadic flooding that occurs with more common weather extremes.
- Even as global deforestation continues, trees continue to be valued as a provider of agricultural commodities like nuts and fruit; as a mitigating resource that removes carbon dioxide from the atmosphere; and also as a staple of adaptation—trees help stabilize soil erosion, better regulate water, as well as provide shade, firewood and fodder.
- Production of the most common commodity staples—wheat, maize and rice—will be challenged by new weather patterns. Adjustments in production, replacement with commodities that can tolerate the new conditions in different regions, and innovations in technology are key elements of adaptation.
- Raising livestock and catching fish and other aquatic products—two of the more common sources of protein—will also be challenged by a new climate. In some areas, different plants, breeds and species can provide substitutions, but in others, adaptation is critical.
- This recalibration of agriculture will eventually extend beyond what is grown and raised. The world’s many cultures must adapt to the changing dinner menu forced upon them due to climate change.
Download Report Here
29 October 2012: The Stockholm International Water Institute (SIWI) has released a report of the overarching conclusions of the 2012 World Water Week, which convened 2500 participants to discuss the theme of water and food security.