Wednesday, January 4, 2012
New crop varieties can cut poverty, study finds!!!
Evidence that new technologies improve small farmers' wellbeing is scarce because the impact of adopting technologies depends on many factors such as the existence of infrastructure, policies and institutions that are often not fully functional in developing countries. For example, technology that increases productivity may not reduce poverty if the farmers do not have access to markets to sell their extra crop.
In addition, some studies have claimed that building capacity is more important than technology for improving livelihoods.
Researchers from CIMMYT selected more than 900 households at random from seven major groundnut growing districts in Uganda and, in 2006, surveyed socioeconomic data and information related to the adoption of improved groundnut varieties. Groundnut is an important crop in Uganda.
Farmers who adopted any of four improved varieties resistant to major pests and diseases — developed by national and international organisations, and released in Uganda between 1999 and 2002 — were compared with non-adopters. The results of the study were published in the October 2011 issue of World Development.
"We found that the adoption of [improved] groundnut varieties significantly increased the net value of income by US$130–254 per hectare," said Menale Kassie, one of the authors of the study. "Adoption of groundnut varieties also significantly reduced poverty as measured by headcount index [the proportion of people below the poverty line] by 7–9 per cent."
In a related study, which has been submitted for publication, Kassie and colleagues found that adopting improved maize varieties also significantly improves rural households' food security and decreases the extent of poverty.
Richard Edema, a plant pathologist and senior lecturer in the school of agricultural sciences at Makerere University, Uganda, said: "Studies [such as this one] can serve as feedback for agricultural scientists to assess whether new [crop] varieties are making real impacts on farmers' lives".
Okello David Kalule, head of the Uganda National Groundnut Improvement Programme, said that, although the new groundnut varieties produce superior yields, some farmers are still growing low-yielding varieties. The reasons for this, he said, include poor agricultural extension services and a lack of access to information about the new varieties.
"Local institutions should be strengthened to collectively improve access to seeds, credit, and information to increase both the spread and intensity of adoption," he said.
Source: www.scidev.net
Monday, January 2, 2012
Poderão o sol e o vento ser a maior fonte de energia do mundo?
Walter Kohn, doutorado (Universidade de Califórnia, Santa Barbara), que em 1998 partilhou o Prémio Nobel de Química, fez notar que a produção total de petróleo e gás natural, que hoje corresponde a cerca de 60% do consumo global de energia, deverá alcançar o seu pico daqui a 10 a 30 anos, seguido de uma queda vertiginosa.
"Estas tendências geraram dois desafios globais sem precedentes ", afirmou. "Um destes é a ameaça de uma falha global de energia aceitável. O outro é o perigo de aquecimento global, inaceitável e iminente, assim como as suas consequências."
Kohn referiu que tais desafios necessitam de uma variedade de respostas. "A mais óbvia será continuar o progresso científico e técnico para o fornecimento de energias alternativas em quantidade e a preços baixos, que sejam seguras, limpas e sem carbono”.
Constatou ainda que os desafios são de natureza global e como tal, o trabalho técnico e científico deverá beneficiar da máxima cooperação a nível internacional, o que felizmente está a começar a acontecer.
Na última década, a produção global de energia fotovoltaica aumentou por um factor de cerca de 90 e a energia eólica por um factor de cerca de 10. Estima que estas duas energias, na verdade infindáveis, terão um aumento robusto na próxima década e no futuro, levando a uma nova era, a era SOL/VENTO na história do Homem, em que a energia solar e eólica se tornarão nas fontes de energia principais no nosso planeta.
Kohn referiu que um outro assunto de importância, cuja incumbência cairá principalmente nos países desenvolvidos, cujas populações estão mais ou menos niveladas, é a redução do consumo de energia per capita.
"Um exemplo flagrante é o consumo per capita de gasolina nos EUA, que é cerca de 5 vezes mais elevado do que a média global” afirmou. "É compreensível que os países menos desenvolvidos queiram aumentar o nível de vida até níveis semelhantes aos dos países desenvolvidos, mas em troca devem estabilizar as suas populações em crescimento."
Kohn fez notar que estava impressionado com os alunos no seu campus que tinham utilizados os seus fundos colectivos para alimentar um edifício desportivo totalmente a energia solar. Comentou que "quando toca em mostrar dinamismo dos jovens na área da conservação de energia e eficiência energética e aquecimento global, eles são fantásticos. Este é um grande compromisso social para os tempos em que vivemos."
Fonte: www.eneop.pt
Sunday, January 1, 2012
Satellite Studies Reveal Groundwater Depletion around the World
Access to freshwater resources has always been a critical need for human and all forms of life on Earth. With a world population estimated at just shy of 7 billion and growing, the UN Food and Agriculture Organization says agricultural production will need to increase 70% by 2050. As agriculture takes up most of human water use, that’s going to put vastly greater demands and strains on our water resources at a time when climate change is changing temperature and precipitation levels and patterns in ways that cannot be predicted at local levels but are likely to make this even more difficult to achieve.
One thing that has been determined is that groundwater levels have dropped in many places around the world in the past nine years, including across key agricultural areas, such as southern Argentina, western Australia and the western US, according to a pair of studies of satellite gravity monitoring data conducted by researchers at the University of California Center for Hydrologic Modeling in Irvine, Science News reports.
The GRACE Project
Groundwater depletion is especially pronounced beneath parts of California, India, the Middle East and China. Besides showing that water is being pumped out of underground groundwater aquifers faster than it’s being replenished, the results raise concerns that farming in particular is the primary cause, according to the Science News report.
“Groundwater is being depleted at a rapid clip in virtually of all of the major aquifers in the world’s arid and semiarid regions,” cautioned UC Center hydrologist Jay Famiglietti, whose team presented the results at a Dec. 6 meeting of the American Geophysical Union.
The Gravity Recovery and Climate Experiment (GRACE), conducted jointly by NASA and the German Aerospace Center, has been taking monthly snapshots of global groundwater used in the two studies since 2002. GRACE data is especially useful in accumulating data across countries where governments do not maintain extensive networks of groundwater monitoring wells. While the US maintains an extensive nationwide network of such wells, countries, such as China, do not.
Nicknamed Tom and Jerry, GRACE’s two satellites are pulled apart and pushed together by variations in the gravitational pull of the areas of the earth they pass over. While mountains and other large concentrations of mass have large, steady impacts on earth’s gravitational pull on the areas where they’re found, water moves over time and creates small fluctuations that the two satellites sense.
Isolating groundwater changes
To isolate the effects of groundwater in particular, researchers have to subtract the effects of snow pack, rivers, lakes and soil moisture, the Science Times article explains. Doing so, they can detect changes in groundwater levels greater than one centimeter (~0.4 inches) over an area about the size of Illinois.
Results of analyzing the data obtained in the two UC Center studies shows that China’s been underestimating groundwater use. GRACE’s measurements indicate that water levels have been dropping 6 or 7 centimeters per year beneath the country’s northeast plains.
Short-term variability in climate is also taking its toll on groundwater levels. having suffered recent droughts, aquifers in Patagonia and the southeastern US now store less groundwater than they did in 2002.
Farming is almost certainly the largest contributing factor, however. Booming agriculture in northern India, takes some 18 cubic kilometers of water out of the ground every year, more than enough to fill 7 million Olympic-size swimming pools, according to Science News.
Farmers in California’s Central Valley, which accounts for nearly 1/6 of irrigated land in the entire country, pump nearly 4 cubic kilometers of water per year out from underground. The valley has been sinking for decades as more wells have been drilled and water pumped out, land subsidence that’s also been occurring and causing increasing concerns, and costly remediation efforts, in Mexico City.
Aquifers in arid and desert areas with fast-growing populations, such as the Middle East, are also being depleted. The “fossil water” that fell millions of years ago and is now stored in the Arabian aquifer beneath Saudi Arabia and neighboring countries is being pumped out faster than it’s being replenished.
Just how much water is there?
Climate change only makes the problem more acute, according to UC Center’s Famiglietti. Precipitation patterns are becoming more extreme, with the severity of droughts increasing. Wet areas are becoming wetters and dry areas drier, Science News reports, and that may accelerate groundwater depletion in some areas.
A big question remains unanswered, however, as hydrologists don’t really know just how large these aquifers are and just how much water is left in them. That’s because GRACE can only show changes in aquifer levels, not their total volume.
Yet while they lack reliable estimates for the total amount of groundwater stored in the world’s aquifers, it’s become clear to hydrologists studying them that water use has become unsustainable in many areas. Better irrigation systems would help reduce water usage, as could channeling water runoff into aquifers during wet periods
Access to freshwater resources has always been a critical need for human and all forms of life on Earth. With a world population estimated at just shy of 7 billion and growing, the UN Food and Agriculture Organization says agricultural production will need to increase 70% by 2050. As agriculture takes up most of human water use, that’s going to put vastly greater demands and strains on our water resources at a time when climate change is changing temperature and precipitation levels and patterns in ways that cannot be predicted at local levels but are likely to make this even more difficult to achieve.
One thing that has been determined is that groundwater levels have dropped in many places around the world in the past nine years, including across key agricultural areas, such as southern Argentina, western Australia and the western US, according to a pair of studies of satellite gravity monitoring data conducted by researchers at the University of California Center for Hydrologic Modeling in Irvine, Science News reports.
The GRACE Project
Groundwater depletion is especially pronounced beneath parts of California, India, the Middle East and China. Besides showing that water is being pumped out of underground groundwater aquifers faster than it’s being replenished, the results raise concerns that farming in particular is the primary cause, according to the Science News report.
“Groundwater is being depleted at a rapid clip in virtually of all of the major aquifers in the world’s arid and semiarid regions,” cautioned UC Center hydrologist Jay Famiglietti, whose team presented the results at a Dec. 6 meeting of the American Geophysical Union.
The Gravity Recovery and Climate Experiment (GRACE), conducted jointly by NASA and the German Aerospace Center, has been taking monthly snapshots of global groundwater used in the two studies since 2002. GRACE data is especially useful in accumulating data across countries where governments do not maintain extensive networks of groundwater monitoring wells. While the US maintains an extensive nationwide network of such wells, countries, such as China, do not.
Nicknamed Tom and Jerry, GRACE’s two satellites are pulled apart and pushed together by variations in the gravitational pull of the areas of the earth they pass over. While mountains and other large concentrations of mass have large, steady impacts on earth’s gravitational pull on the areas where they’re found, water moves over time and creates small fluctuations that the two satellites sense.
Isolating groundwater changes
To isolate the effects of groundwater in particular, researchers have to subtract the effects of snow pack, rivers, lakes and soil moisture, the Science Times article explains. Doing so, they can detect changes in groundwater levels greater than one centimeter (~0.4 inches) over an area about the size of Illinois.
Results of analyzing the data obtained in the two UC Center studies shows that China’s been underestimating groundwater use. GRACE’s measurements indicate that water levels have been dropping 6 or 7 centimeters per year beneath the country’s northeast plains.
Short-term variability in climate is also taking its toll on groundwater levels. having suffered recent droughts, aquifers in Patagonia and the southeastern US now store less groundwater than they did in 2002.
Farming is almost certainly the largest contributing factor, however. Booming agriculture in northern India, takes some 18 cubic kilometers of water out of the ground every year, more than enough to fill 7 million Olympic-size swimming pools, according to Science News.
Farmers in California’s Central Valley, which accounts for nearly 1/6 of irrigated land in the entire country, pump nearly 4 cubic kilometers of water per year out from underground. The valley has been sinking for decades as more wells have been drilled and water pumped out, land subsidence that’s also been occurring and causing increasing concerns, and costly remediation efforts, in Mexico City.
Aquifers in arid and desert areas with fast-growing populations, such as the Middle East, are also being depleted. The “fossil water” that fell millions of years ago and is now stored in the Arabian aquifer beneath Saudi Arabia and neighboring countries is being pumped out faster than it’s being replenished.
Just how much water is there?
Climate change only makes the problem more acute, according to UC Center’s Famiglietti. Precipitation patterns are becoming more extreme, with the severity of droughts increasing. Wet areas are becoming wetters and dry areas drier, Science News reports, and that may accelerate groundwater depletion in some areas.
A big question remains unanswered, however, as hydrologists don’t really know just how large these aquifers are and just how much water is left in them. That’s because GRACE can only show changes in aquifer levels, not their total volume.
Yet while they lack reliable estimates for the total amount of groundwater stored in the world’s aquifers, it’s become clear to hydrologists studying them that water use has become unsustainable in many areas. Better irrigation systems would help reduce water usage, as could channeling water runoff into aquifers during wet periods
Source: www.enn.com
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