Just when the ESA Mars Express spacecraft was collecting data on methane emissions on Mars, leading some to speculate it might be a biomarker, Science Now reported new findings that indicate methane can form naturally in Earth’s mantle by heating water, iron oxide and calcite under pressure (see also Physics Web). This demonstrates that “hydrocarbons could be produced without the byproducts of life,” and that “The methane recently detected on Mars … may not indicate life, because it could have been produced from simple elements.” It also indicates there could be vast yet currently inaccessible reservoirs of natural gas in Earth’s mantle. This means also that future missions such as the Space Interferometry Mission and Terrestrial Planet Finder may not be able to assume that the detection of methane is an indicator of the presence of life on a distant planet. Nor could Cassini scientists assume that methane at Titan was a precursor to biology.(Visited 18 times, 1 visits today)FacebookTwitterPinterestSave分享0
Charl and Ella van der Merwe spoke about their Write Project, which supplies disadvantaged communities with stationeryMeyerton, Saturday 14 September 2013 – South African youngsters are taking matters into their own hands to help ailing communities in all nine provinces of South Africa, and their efforts are not going unnoticed.Brand South Africa teamed up with the President’s Award for Youth Empowerment – which this year celebrated its 30th anniversary – to organise three Youth Dialogue and Action Workshops to acknowledge those individuals playing their part. The most recent of the Brand South Africa Play Your Part – National Development Plan Outreach workshops was held at the Oprah Winfrey Leadership Academy for Girls in Meyerton, in Gauteng, on 14 September.The purpose of the workshops was to expose President’s Award participants to The National Development Plan (NDP) which was presented to Parliament last year by the Minister in the Office of The President, Trevor Manuel. The aims of the NDP, its broad objectives, and practical ways that young people can be involved in the realisation of its Vision 2030 were a common theme at each of the workshops.Kids from across South Africa took time out to help Meyerton High School At each, delegates were also involved in service projects, which included a literacy project, a second-hand clothing distribution project and refurbishing desks for an under-resourced school. Marius Gwebu, from Barberton Correctional Services, was on hand to help the youngsters work on the desks for Meyerton High School, and about 150 desks were refurbished by the participants and their parents. Gwebu belongs to an initiative in Barberton that restores desks at the correctional facility for schools in Mpumalanga.Leo Makgamath, the programme manager for civil society at Brand South Africa, who worked on a few desks, took the opportunity to interact with the youngsters. He spoke to them about shaping their future today and not waiting for tomorrow. Lerato Funeka helped Makgamath with some of the desks and the 22-year-old spoke with pride about restoring old desks for Meyerton High School, which he attended.“I believe that I’ve been through a lot with that school and the projects that are being done through the President’s Award will not only help with desks but will also help with books in the library, among others,” he said.Leaders of todayMakgamath said that the youth were not leaders of tomorrow but rather leaders of today. An Mpumalanga project stood out for him, he added. It involved a group of 32 children and teachers, who planted food gardens in impoverished areas that were not only used for the schools, but for the community at large. Apart from their feeding schemes, the group also cared for the elderly in the community by clothing them, feeding them and cleaning their homes for them.Another project that stood out for Makgamath was a stationery drive run by two Tshwane residents. Charl and Ella van der Merwe run the Write Project, which involves collecting stationery from affluent communities and distributing this to disadvantaged youth. Makgamath said it was initiatives such as these that broke the boundaries between groups and encouraged social cohesion among different races and social classes. This, he said, was laying the foundation for a cohesive nation.Ahead of the workshop, Brand South Africa’s chief executive office, Miller Matola, said: “We have been impressed by the quality of questions and input, coming from the young people who attend these Dialogue and Action Workshops. It shows that many of our youth are serious about understanding the NDP and becoming involved in its implementation. South Africa has recently improved in terms of innovation on the World Economic Forum Innovation Pillar. Young people are ideally placed to participate in a knowledge-based economy, which is the trajectory South Africa is pursuing.”The NDP offers a long-term strategy of eliminating poverty and reducing inequality by 2030. According to the plan, South Africa can realise these goals by drawing on the energies of its people, growing an inclusive economy, building capabilities, enhancing the capacity of the state, and promoting leadership and partnerships throughout society.The President’s Award for Youth Empowerment has over 15 000 active participants drawn from schools (both state and independent), community youth groups, residential youth facilities and correctional services. The aim of the awards programme is to provide a holistic framework for purposeful self-development of young people between the ages of 14 and 24. These awards are affiliated with the Duke of Edinburgh’s International Award Association and the patron-in-chief is President Jacob Zuma.Through these awards, Youth Dialogue and Action Workshops have been running since 2008, encouraging participants from a broad diversity of socio-economic and cultural backgrounds to engage with themes relevant to their lives as young South Africans. The chief executive officer of the President’s Award, Martin Scholtz, said the programme demanded young people take responsibility for their own development and the development of those around them.“Engaging young people in their role in the realisation of Vision 2030 is critical. The award programme is about action and we are excited to make the link between what award participants are already doing on the ground and the objectives of the NDP, through these Dialogue and Action Workshops. The NDP is not a government initiative – it’s a citizen’s initiative,” said Scholtz.This dialogue was the third in a series in which youth have interacted with representatives from the President’s Awards, the NDP and Brand South Africa. The first two were held in East London and Cape Town on 31 August and 7 September, respectively.
Adding up the carbon impactConverting a plant from coal to wood is fairly simple — “a quick and comparatively cheap way to shift towards renewables,” Styles writes — but the equation gets a lot more complicated when details of “carbon accounting” are considered.Ironically, trucking wood pellets to a port and then shipping them across the Atlantic isn’t what tips the scales against wood, in part because ships can carry huge amounts of cargo efficiently. Even the processing of pellets, including grinding and drying the fiber, isn’t a fatal flaw.Instead, it’s the source of the wood that’s turned into pellets that counts.Coal releases carbon that has been stored for millions of years, while wood releases carbon that has only recently been captured through photosynthesis, and newly planted trees begin capturing carbon again in a relatively short amount of time. This balance of storing and releasing carbon, however, isn’t uniform.Styles writes, “The government study notes that wood from intensively managed plantations could mean more carbon taken up by growing trees than emitted by the transport and processing of the pellets, leading to a net reduction in emissions even before avoided coal emissions are accounted for. Conversely … the study found that if wood pellets are sourced from regenerated natural forests, carbon emissions could be five times higher than from burning coal.”Drax doesn’t agree. “Provided the rate at which carbon is absorbed by the forest as a whole equals or exceeds the rate at which it is being removed there is no net release of carbon,” the utility says. “Healthy demand for wood stimulates supply and ensures forests remain as forests. That is why forest cover in the U.S. is growing year on year and has been growing for each of the last 50 years.”Drax insists that its sustainability policy requires that the sourcing of pellets not lead to a net increase in carbon levels, which is the case “at a landscape level, at state level, across the southeast U.S. and across the U.S. as a whole.” NRDC: Burning Trees to Make Electricity is an ‘Environmental Disaster’ Biomass Electricity Production: How Green Is It?Do Wood-Burning Power Plants Make Sense?Germany’s Bioenergy VillagesVÃ¤xjö, Sweden, is a Model of SustainabilityTwo Biomass Plants in Maine to CloseHeating With Wood PelletsShould Green Homes Burn Wood? RELATED ARTICLES “A U.K. government study found that electricity generated from regenerated forests could have a carbon intensity five times higher than coal,” Styles says. “Burning wood also releases nitrogen oxides and carcinogenic compounds.” Six millions tons of wood pellets manufactured from trees harvested in the U.S. were shipped to Europe last year to help utilities there meet renewable energy goals, but a growing number of environmentalists say that the program does more harm than good. In an article posted at Science 2.0, David Styles, a lecturer at Bangor University in Wales, said that shipments in 2015 were nearly double the amount of pellets shipped in 2013. Half of them went to a single plant: Britain’s Drax power station, which is switching from coal to biomass in order to reduce carbon emissions and grab what are called “renewable obligation certificates.”The pellets were manufactured from wood harvested in five U.S. states: Louisiana, Georgia, Florida, Alabama, and Virginia.Converting power plants from coal to wood may look good on paper, but a number of environmental groups are arguing just the opposite. In a paper published last fall, the groups argued that burning pellets to produce “bioenergy” has a number of ugly side effects, including soil and water pollution, the growth of industrial scale logging, and a loss of biodiversity. The groups argue that biomass should be excluded from the European Union’s next Renewable Energy Directive. Environmental concerns are not newA wide scale use of wood pellets to generate electricity also has been criticized by the Natural Resources Defense Council, which said three years ago that the practice could double logging rates and significantly increase carbon emissions.The environmental impact of the U.S. wood pellet trade may be disputed, but there’s not much doubt that it’s been a boon for the forest industry in some states. Forbes reported last year that the number of wood pellet plants has jumped significantly — two new mills planned In North Carolina alone will mean investments of $214 million and 160 permanent jobs by next year.