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The challenge facing industrialised countries is to negotiate a long-term global regulatory framework, with intermediate targets, that can reduce greenhouse emissions to a level that limits the increase in global mean surface temperature to 2oC above pre-industrial levels.
That was the message delivered to delegates at the British Society of Animal Science's Livestock and Global Climate Change meeting, held in Tunisia, by Defra's chief scientific advisor Bob Watson.
"The long-term challenge is to meet the goal of Article 2 of the UN Framework Convention on Climate Change (UNFCCC), in other words the ?stabilisation of greenhouse concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system, and in a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner'," he said, outlining why climate change is an environmental, development and security issue.
Professor Watson explained that human activities are changing the Earth's climate and further human-induced climate change is inevitable. "The question is not whether the Earth's climate will change in response to human activities, but rather where, when and by how much. The Earth's climate has warmed, on average by about 0.7oC, during the past 100 years, with the decades of the 1990s and 2000s being the warmest.
"The temporal and spatial patterns of precipitation have changed, sea levels have risen by up to 25cm, most non-polar glaciers are retreating, and the extent and thickness of Arctic sea ice in summer are decreasing.
"And projected changes in the atmospheric concentrations of greenhouse gases and aerosols are projected to result in increases in global mean surface temperatures, between 1990 and 2100, of 1.1oC to 6.4oC, with land areas warming more than the oceans, and high latitudes warming more than the tropics," he added.
Most industrialised countries have ratified the Kyoto Protocol, which mandates industrialised countries to reduce their emissions on an average by 5.2% between 2008 and 2012 relative to emissions in 1990, with individual industrialised country targets varying. There are no emissions targets for developing countries.
"And given that many industrialised countries will not meet their reduction targets with domestic actions alone, this provides significant opportunities for carbon trading, which are likely to provide sustainable development benefits for many developing countries," he said.
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details:
B Watson: "Climate change: an environmental, development and security issue."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 0131 445 4508
Attempts to calculate the large-scale consequences of global warming for agriculture and food production, although difficult, do confirmed that most of the increase in production will come from the agriculture of developed countries, which mostly ?benefit' from climate change.
"And these countries will have to compensate for declines projected, for the most part, in developing countries with declines in agricultural productivity approaching between 20 and 25% for some countries like Mexico, Nigeria and South Africa," said Bernard Seguin, a global bioclimatologist based at INRA, France, who presented his paper, on the consequences of global warming for agriculture and food production, to delegates at the British Society of Animal Science's Livestock and Global Climate Change meeting, held recently in Tunisia.
And Dr Seguin warned that the resulting increase in the number of people marginally at risk of hunger - expected to rise from 380 million to 1,300 million by 2080 - could be underestimated due to the increased frequency and severity of extreme weather events.
Increased elevation of CO2 atmospheric concentration, which will impact on pastures as well as annual crops, will stimulate increased photosynthesis - between 10 and 20% with 550ppm for temperate species such as wheat, rice and soya - and, therefore, production.
"And higher elevated temperatures are generally favourable for growth in cold and temperate climates, except when they exceed the optimum and even attain detrimental thresholds in the case of extreme events, and are generally unfavourable for warm areas. For perennial species, like grass, warmer conditions will mean earlier spring growth and a significant increase of the length of the growing season," he said.
"Changes in rainfall will more or less modulate the potential changes in plants resulting from these effects of temperature increase. It is certain that tendencies towards drier conditions in areas like the Mediterranean basin or the south of Africa will cancel out the positive potential impact of higher CO2 levels or milder temperatures."
Dr Seguin added that crop models, used to simulate the effects of a climate change on crops currently cultivated, show that there will be adaptation, which will involve changes in the crop/livestock systems combining changes in varieties and cultural practices.
"And it is possible to estimate that yields will improve by between 10% and 15% in temperate regions where moderate to medium increases in local mean temperature - between 1?C and 3?C - along with associated CO2 increases and rainfall changes, will have a small beneficial impact on crop yields.
"At lower latitudes, particularly the seasonally dry tropics, even moderate increases in temperature are likely to have a negative impact on the yield of major cereal crops. And further global warming has increasingly negative impacts in all regions," he said.
With regards to livestock, the model indicates the same tendency for pasture production. "It will be accompanied by changes in forage quality and grazing behaviour. And additional thermal stress on livestock has the potential to reduce productivity and conception rates."
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details:
B Seguin: "The consequences of global warming for agriculture and food production."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 0131 445 4508
Green house gas (GHG) emissions are highly variable between and within production systems and the optimisation, or management, of animal production systems has not yet been considered so there is room for possible improvement.
This was just some of the positive news for delegates attending the British Society of Animal Science's Livestock and Global Climate Change meeting, held in Tunisia, from INRA France, Jean-Yves Dourmad.
"Many mitigation strategies are already available and these focus on improving animal efficiency, changing feeding strategies and improving manure management. And they require a whole system evaluation," he said.
"In the future, on-farm evaluation tools and new technologies, based on farm modelling, will be developed to assist decision making.
"But more research is needed to better evaluate GHG emissions, particularly N2O, in alternative production systems."
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details: J Dourmad, C Rigolot and H van der Werf: "Emission of green house gas, developing management and animal farming systems to assist mitigation."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 0131 445 4508
There is potential to reduce emissions from livestock systems by selection on correlated traits.
"Selecting on traits that improve the efficiency of the system, for example residual feed intake and longevity, will have a favourable effect on the overall emissions from the system," the SAC's Eileen Wall told delegates attending the British Society of Animal Science's Livestock and Global Climate Change meeting, held in Tunisia.
"Improvements in system efficiency are also likely to have a favourable impact on the future sustainability of the system.
"And the development of breeding goals that incorporate environmental concerns is possible. However, new measurement techniques for direct and indirect emissions traits will improve the potential to reduce emissions by harnessing genetic selection."
Genetic improvement of livestock is a particularly effective technology, producing permanent and cumulative changes in performance, according to Dr Wall.
"Focusing on ruminant species, there are essentially three routes through which genetic improvement can help to reduce emissions per kilogram of product," she explained.
"The first is as a result of improved productivity and efficiency; the second as a result of reducing wastage at the herd or flock level; and the third is as a direct response to selection on emissions, if or when these are measurable.
"Our work has shown that selection for production efficiency and broader breeding goals can - and has - resulted in lower emissions.
"We've seen lower emission per unit output, rather than per animal, which offers benefits for future sustainability - both economic and in terms of welfare," said Dr Wall.
"Breeding goals that include efficiency traits can help to select for reduced emissions and breeding goals can be developed to consider environmental issues."
She added that grass/plant breeding and animal breeding would interact in the future. "Whole systems of farming that reduce nutrient waste will evolve and may be facilitated by integrated food supply chains.
"But further modelling work is required at the whole system level to identify sensitive areas and to help policy makers identify methods of encouraging farmers to adopt different production methods over time."
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details:
E Wall, MJ Bell And G Simm: "Developing breeding schemes to assist with mitigation."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 0131 445 4508
Reducing greenhouse gas emissions from agriculture is a laudable and necessary objective. It should be done, however, in the knowledge that not only will there be ?disbenefits' as well as benefits, but also that these ?disbenefits' will be compounded by issues relating to competition for resources.
These were just some of the strong views that Chris Pollock from Aberystwyth University formed during his research into the impacts on livestock agriculture of competition for resources - views he shared with delegates attending the British Society of Animal Science's Livestock and Global Climate Change meeting, held in Tunisia.
"Pressures to increase production will grow at the same time as pressures to reduce carbon footprint will intensify and the intensive livestock sector is particularly vulnerable to these conflicting pressures."
Professor Pollock stressed that his presentation, which examined the impacts on livestock agriculture of competition for resources, reflected his views and was not based on any external support or funding.
"The conclusions are open to debate and disagreement. If, however, the conclusions are borne out by events in the next few years, the implications for the industry, the food chain and policy makers are considerable.
"The delivery of a more sustainable food chain for livestock products will require policy and regulatory change, changes in consumer behaviour and awareness and forward planning on behalf of the industry."
He said that livestock agriculture is very sensitive to resource competition and competition for water, land and feed will increase at the same time as demand is rising. This will increase the risk of insecurity of supply and possibly reduce food safety. And the social consequences of this are unknown.
"The livestock sector is particularly vulnerable to change, given that it competes substantially with direct human feeding for key resources," he told delegates.
"Unfortunately most of the changes that we are likely to see during the next 50 years are going to make both mitigation and adaptation more difficult and do, in my view, and present real challenges to the livestock industry."
He explained that intensive livestock production systems, even those involving ruminants, rely substantially on bought-in feedstuffs. "And demand for animal products is increasing worldwide, driven mainly by increasing prosperity in Asia and to a lesser extent South America, and IFPRI have estimated that an extra 300 million tonnes of grain will be needed by 2050 just to feed to livestock."
At the same time, overall human demand for arable crops is increasing, driven mainly by population growth, predicted to reach nine billion within the 21st century.
"The development of eco-efficient livestock systems is a logical response to increased prices and reduced security of bought-in feed but will, inevitably, lead to an increase in greenhouse gas emissions per unit of production," he added.
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details:
C Pollock: "Impacts on livestock agriculture of competition for resources."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 0131 445 4508
Decreasing the production of methane from ruminant livestock is desirable both as a strategy to reduce global greenhouse gas emissions and as a means of improving feed conversion efficiency. And decreases in methane (CH4) production have been achieved using different approaches that induce changes in metabolic pathways, that alter the rumen microbial consortium and/or that influence the animal digestive physiology.
That was the good news that C?cile Martin, INRA France, shared with delegates attending the British Society of Animal Science's Livestock and Global Climate Change meeting, held in Tunisia. Her paper presented a selection of proven, as well as some potential, mitigation strategies.
"Methane mitigation in ruminants is possible through various strategies. And today the feeding management approach is the most developed," said Dr Martin, who added that other strategies, including biotechnologies and additives, were promising but the diversity and plasticity of functions of the rumen bacterial and methanogenic communities could be a limiting factor for their successful application.
"In any case, before practical solutions are proposed for field application, more research is needed. The sustainability of methane suppressing strategies is an important issue," she explained.
"Strategies have been proposed to reduce methanogenesis in ruminants and their complete evaluation should include consequences on animal performances, safety for the ruminant and the consumer, and economical viability.
"And the environmental impacts of such strategies should also take into consideration a global vision of production systems that considers all green house gas emissions from the animal up to the farm scale as well as grassland use," she added.
Presented to the British Society of Animal Science's Livestock and Global Climate Change meeting, May 17 to 20, 2008, Hammamet, Tunisia.
Full details:
C Martin, M Doreau and DP Morgavi: "Methane mitigation in ruminants: from rumen microbes to the animal."
http://www.bsas.org.uk/Meetings_&_Workshops/Past_Meetings/
For further information contact: BSAS on 01314 454508