Changing global diets is vital to reducing climate change

fpjl2 — Mon, 01 Sep 2014 08:34:13 +0000

A new study, published today in Nature Climate Change, suggests that 鈥� if current trends continue 鈥� food production alone will reach, if not exceed, the global targets for total greenhouse gas (GHG) emissions in 2050.

探花直播study鈥檚 authors say we should all think carefully about the food we choose and its environmental impact. A shift to healthier diets across the world is just one of a number of actions that need to be taken to avoid dangerous climate change and ensure there is enough food for all.

As populations rise and global tastes shift towards meat-heavy Western diets, increasing agricultural yields will not meet projected food demands of what is expected to be 9.6 billion people - making it necessary to bring more land into cultivation.

This will come at a high price, warn the authors, as the deforestation will increase carbon emissions as well as biodiversity loss, and increased livestock production will raise methane levels. They argue that current food demand trends must change through reducing waste and encouraging balanced diets.

If we maintain 鈥榖usiness as usual鈥�, say the authors, then by 2050 cropland will have expanded by 42% and fertiliser use increased sharply by 45% over 2009 levels. A further tenth of the world鈥檚 pristine tropical forests would disappear over the next 35 years.

探花直播study shows that increased deforestation, fertilizer use and livestock methane emissions are likely to cause GHG from food production to increase by almost 80%. This will put emissions from food production alone roughly equal to the target greenhouse gas emissions in 2050 for the entire global economy.

探花直播study鈥檚 authors write that halving the amount of food waste and managing demand for particularly environmentally-damaging food products by changing global diets should be key aims that, if achieved, might mitigate some of the greenhouse gases causing climate change.

鈥淭here are basic laws of biophysics that we cannot evade,鈥� said lead researcher Bojana Bajzelj from the 探花直播 of Cambridge鈥檚 Department of Engineering, who authored the study with colleagues from Cambridge鈥檚 departments of Geography and Plant Sciences as well as the 探花直播 of Aberdeen's Institute of Biological and Environmental Sciences.

鈥� 探花直播average efficiency of livestock converting plant feed to meat is less than 3%, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals that provide meat for humans. 探花直播losses at each stage are large, and as humans globally eat more and more meat, conversion from plants to food becomes less and less efficient, driving agricultural expansion and land cover conversion, and releasing more greenhouse gases. Agricultural practices are not necessarily at fault here 鈥� but our choice of food is,鈥� said Bajzelj.

鈥淚t is imperative to find ways to achieve global food security without expanding crop or pastureland. Food production is a main driver of biodiversity loss and a large contributor to climate change and pollution, so our food choices matter.鈥澛�

探花直播team analysed evidence such as land use, land suitability and agricultural biomass data to create a robust model that compares different scenarios for 2050, including scenarios based on maintaining current trends.

One scenario investigated by the team is on the supply side: the closing of 鈥榶ield gaps鈥�. Gaps between crop yields achieved in 鈥榖est practice鈥� farming and the actual average yields exist all over the world, but are widest in developing countries 鈥� particularly in Sub-Saharan Africa. 探花直播researchers say that closing these gaps through sustainable intensification of farming should be actively pursued.

But even with the yield gaps closed, projected food demand will still require additional land 鈥� so the impact on GHG emissions and biodiversity remains. Bajzelj points out that higher yields will also require more mineral fertiliser use and increased water demand for irrigation.

Food waste, another scenario analysed by the team, occurs at all stages in the food chain. In developing countries, poor storage and transportation cause waste; in the west, wasteful consumption is rife. 鈥� 探花直播latter is in many ways worse because the wasted food products have already undergone various transformations that require input of other resources, especially energy,鈥� said Bajzelj.

Yield gap closure alone still showed a greenhouse gas increase of just over 40% by 2050. Closing yield gaps and halving food waste still showed a small increase of 2% in greenhouse gas emissions. When healthy diets were added, the model suggests that all three measures combined result in agricultural GHG levels almost halving from their 2009 level 鈥� dropping 48%.

鈥淲estern diets are increasingly characterised by excessive consumption of food, including that of emission-intensive meat and dairy products. We tested a scenario where all countries were assumed to achieve an average balanced diet - without excessive consumption of sugars, fats, and meat products. This significantly reduced the pressures on the environment even further,鈥� said the team.

探花直播鈥榓verage鈥� balanced diet used in the study is a relatively achievable goal for most. For example, the figures included two 85g portions of red meat and five eggs per week, as well as a portion of poultry a day.

鈥淭his is not a radical vegetarian argument; it is an argument about eating meat in sensible amounts as part of healthy, balanced diets,鈥� said Cambridge co-author Prof Keith Richards. 鈥淢anaging the demand better, for example by focusing on health education, would bring double benefits 鈥� maintaining healthy populations, and greatly reducing critical pressures on the environment.鈥�

Co-author Prof Pete Smith from the 探花直播 of Aberdeen said: 鈥渦nless we make some serious changes in food consumption trends, we would have to completely de-carbonise the energy and industry sectors to stay within emissions budgets that avoid dangerous climate change. That is practically impossible 鈥� so, as well as encouraging sustainable agriculture, we need to re-think what we eat.鈥�

鈥淐utting food waste and moderating meat consumption in more balanced diets, are the essential 鈥榥o-regrets鈥� options,鈥� added Bajzelj.

Inset image: cattle_feedlot_09 by NDSU Ag Communication (Att-NC-SA)

Healthier diets and reducing food waste are part of a combination of solutions needed to ensure food security and avoid dangerous climate change, say the team behind a new study.

Food production is a main driver of biodiversity loss and a large contributor to climate change and pollution, so our food choices matter

Bojana Bajzelj

Joshua Bousel

Fajitas. Banner image: ...eat meat! by James Vaughn

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Botanic Garden names new Director

sjr81 — Wed, 09 Jan 2013 09:48:12 +0000

Dr Glover, currently Reader in Evolution and Development in the Department of Plant Sciences, said: 鈥� 探花直播Botanic Garden is a central and much-loved part of both the 探花直播 and the wider community. It is a great privilege and honour to be asked to lead its continued development.

鈥淚 am very much looking forward to working with the Garden's highly-skilled and dedicated staff to develop further the collections and to ensure they play their full part in botanical research and teaching, both in the 探花直播 and worldwide.鈥�

Dr Glover read Plant and Environmental Biology at St Andrews before completing her PhD at the John Innes Centre in the molecular genetics of cellular differentiation in the plant epidermis. She came to Cambridge first as a Junior Research Fellow at Queens' College, before progressing from Lecturer to Reader in the Department of Plant Sciences.聽 A Fellow of the Linnean Society, she was awarded the Linnean Society Bicentennial Medal in 2010 and she received the William Bate Hardy prize from the Cambridge Philosophical Society in 2011.

探花直播Botanic Garden in Cambridge was established on its current site by Professor John Stevens Henslow, mentor to Charles Darwin, and opened to the public in 1846.聽探花直播Garden curates, develops and makes accessible to the public the living plant research collection of the 探花直播. This today numbers in excess of 8,000 species and includes nine National Collections. 探花直播collections are displayed in a seamless patchwork of gardens and plantings that, together with the finest arboretum in the region, compose a stunning landscape of 40 acres which is itself Grade II* listed. 探花直播Garden has seen its visitor numbers more than double in the last decade to around 200,000 annual visits.

Professor Keith Richards, Chair of the Botanic Garden Syndicate, said: 鈥淲e are delighted that Beverley will be the new Director of the 探花直播's Botanic Garden. She is well-known to everyone in the Garden, having served on the Syndicate for ten years, and has already made many highly-valued contributions to its outreach programme and to its integration into 探花直播 teaching.

鈥淏everley鈥檚 own interdisciplinary work will help to strengthen the Garden's research role and build on the relationships between the Garden, the Department of Plant Sciences, the Sainsbury Laboratory, and the Cambridge Conservation Initiative.鈥�

Professor Sir David Baulcombe, Regius Professor of Botany and Head of the Department of Plant Sciences, added: 鈥淲e warmly welcome the appointment of Dr Glover to the Directorship of the Botanic Garden, especially because her research activity will reinforce the Garden's scientific links with the Department."

Dr Beverley Glover has been named as the new Director of Cambridge 探花直播 Botanic Garden. Dr Glover will take up the post, and the associated Professorship of Plant Systematics and Evolution to which she has been elected, in July 2013.

探花直播Botanic Garden is a central and much-loved part of both the 探花直播 and the wider community.

Beverley Glover

Dr Beverley Glover

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探花直播 of Cambridge - Keith Richards

Changing global diets is vital to reducing climate change

Botanic Garden names new Director