Thornton P.K.,CGIAR Research Programme on Climate Change |
Ericksen P.J.,Kenya International Livestock Research Institute |
Herrero M.,CSIRO |
Challinor A.J.,University of Leeds
Global Change Biology | Year: 2014
The focus of the great majority of climate change impact studies is on changes in mean climate. In terms of climate model output, these changes are more robust than changes in climate variability. By concentrating on changes in climate means, the full impacts of climate change on biological and human systems are probably being seriously underestimated. Here, we briefly review the possible impacts of changes in climate variability and the frequency of extreme events on biological and food systems, with a focus on the developing world. We present new analysis that tentatively links increases in climate variability with increasing food insecurity in the future. We consider the ways in which people deal with climate variability and extremes and how they may adapt in the future. Key knowledge and data gaps are highlighted. These include the timing and interactions of different climatic stresses on plant growth and development, particularly at higher temperatures, and the impacts on crops, livestock and farming systems of changes in climate variability and extreme events on pest-weed-disease complexes. We highlight the need to reframe research questions in such a way that they can provide decision makers throughout the food system with actionable answers, and the need for investment in climate and environmental monitoring. Improved understanding of the full range of impacts of climate change on biological and food systems is a critical step in being able to address effectively the effects of climate variability and extreme events on human vulnerability and food security, particularly in agriculturally based developing countries facing the challenge of having to feed rapidly growing populations in the coming decades. © 2014 The Authors.
Challinor A.J.,University of Leeds |
Challinor A.J.,CGIAR Research Programme on Climate Change |
Watson J.,University of Leeds |
Lobell D.B.,Stanford University |
And 4 more authors.
Nature Climate Change | Year: 2014
Feeding a growing global population in a changing climate presents a significant challenge to society. The projected yields of crops under a range of agricultural and climatic scenarios are needed to assess food security prospects. Previous meta-analyses have summarized climate change impacts and adaptive potential as a function of temperature, but have not examined uncertainty, the timing of impacts, or the quantitative effectiveness of adaptation. Here we develop a new data set of more than 1,700 published simulations to evaluate yield impacts of climate change and adaptation. Without adaptation, losses in aggregate production are expected for wheat, rice and maize in both temperate and tropical regions by 2 °C of local warming. Crop-level adaptations increase simulated yields by an average of 7-15%, with adaptations more effective for wheat and rice than maize. Yield losses are greater in magnitude for the second half of the century than for the first. Consensus on yield decreases in the second half of the century is stronger in tropical than temperate regions, yet even moderate warming may reduce temperate crop yields in many locations. Although less is known about interannual variability than mean yields, the available data indicate that increases in yield variability are likely.© 2014 Macmillan Publishers Limited. © 2014 Macmillan Publishers Limited. All rights reserved.
Participants are seen in silhouette as they look at a screen showing a world map with climate anomalies during the World Climate Change Conference 2015 (COP21) at Le Bourget, near Paris, France, December 8, 2015. Since she started out in the 1970s, she has overcome increasingly erratic rainfall by using new technologies and trying out different crops and trees. She even turns her animal manure into biogas, harnessing methane for clean energy. And she doesn't stay quiet about it. She hosts groups of other Kenyan farmers and international researchers on her farm to show them the effectiveness of a mixed crop, livestock and tree farming system in the face of worsening climate pressures. "We try to help ourselves so that climate change will not affect us," she told a discussion about supporting farmers on the sidelines of the recent climate change talks in Paris. It is a strategy that has worked well for her - over the years, she has been able to build a stone house for her family of 11 children, connected to power and water supplies. "Farmers need to get enough crops to sustain their family and reduce poverty, and educate their children," she said. But millions of others are struggling to maintain their yields amid crop damage from severe droughts or flash floods, with no assets in reserve to help them bounce back from a crisis. The International Food Policy Research Institute released a study in Paris showing that climate change is a threat to agricultural growth, affecting productivity, prices and a new global goal to end hunger by 2030. In the Philippines, for instance, climate change is projected to cut per-capita consumption of cereals by 24 percent and fruits and vegetables by 13 percent, increasing the number of people at risk of hunger by 1.4 million in 2030 and 2.5 million by 2050, the institute said. Given that, it is surprising the world "agriculture" does not appear once in the text of the new global agreement to tackle climate change adopted in Paris on Saturday. A key reason for this is that developing nations long resisted including agriculture in the climate negotiations, fearing efforts to feed their people would be compromised by pressure to reduce planet-warming emissions from farms. A 2015 study from the U.N. Food and Agriculture Organization (FAO) found that emissions from agriculture are growing, accounting for around 11 percent of the global total in 2010. The Paris climate agreement refers only indirectly to agriculture, in terms of making sure people have enough to eat. Its non-binding introduction recognizes "the fundamental priority of safeguarding food security and ending hunger, and the particular vulnerabilities of food production systems to the adverse impacts of climate change". The binding part of the deal states that boosting the world's ability to adapt to those impacts and foster climate resilience and low-emissions development should be done "in a manner that does not threaten food production". Yet, despite the politics that largely excluded agriculture, the FAO welcomed the agreement, noting that for the first time ever, food security features in a global climate change accord. "This is a game changer for the 800 million people still suffering from chronic hunger, and for 80 percent of the world's poor who live in rural areas and earn income - and feed their families - from agriculture," FAO Director-General José Graziano da Silva said in a statement after the deal was reached. "By including food security, the international community fully acknowledges that urgent attention is needed to preserve the well-being and future of those who are on the frontline of climate change threats," he added. Others in the agricultural research community and agencies working with small farmers highlighted the widespread inclusion of agricultural policies in the nearly 190 national action plans submitted to the United Nations as a basis for the climate deal. Analysis by the CGIAR Research Programme on Climate Change, Agriculture and Food Security (CCAFS) shows agriculture is discussed in 80 percent of those plans, a signal that addressing agriculture in the context of climate change is a priority. Kanayo F. Nwanze, president of the International Fund for Agricultural Development (IFAD), said this was a good springboard for approaching top decision makers in developing countries about protecting their farmers from climate change. In a report released in Paris, IFAD said technical interventions - like hardier seeds and accurate weather forecasts - are not enough to help small farmers cope, and must be backed up by national strategies, laws and budgets. One major barrier to helping small-scale farmers adapt to extreme weather and reduce emissions from their activities is insufficient money for research and action on the ground, experts noted. The CCAFS study of national climate plans found the 48 least developed countries alone will need funding of $5 billion per year - $3 billion for adaptation and $2 billion for reducing farm emissions. That sum is much higher than current commitments to climate funds for agriculture, and at least 10 percent more per year than multilateral climate funds spent on agricultural projects in the last decade, it said. "Climate finance needs to include agriculture as a key sector, and support countries to implement the plans they have laid out," said CCAFS director Bruce Campbell.
Herrero M.,CSIRO |
Thornton P.K.,CGIAR Research Programme on Climate Change |
Bernues A.,Montana Tech of the University of Montana |
Baltenweck I.,Kenya International Livestock Research Institute |
And 9 more authors.
Global Environmental Change | Year: 2014
We explore how smallholder agricultural systems in the Kenyan highlands might intensify and/or diversify in the future under a range of socio-economic scenarios. Data from approximately 3000 households were analyzed and farming systems characterized. Plausible socio-economic scenarios of how Kenya might evolve, and their potential impacts on the agricultural sector, were developed with a range of stakeholders. We study how different types of farming systems might increase or diminish in importance under different scenarios using a land-use model sensitive to prices, opportunity cost of land and labour, and other variables. We then use a household model to determine the types of enterprises in which different types of households might engage under different socio-economic conditions. Trajectories of intensification, diversification, and stagnation for different farming systems are identified. Diversification with cash crops is found to be a key intensification strategy as farm size decreases and labour costs increase. Dairy expansion, while important for some trajectories, is mostly viable when land available is not a constraint, mainly due to the need for planting fodders at the expense of cropland areas. We discuss the results in relation to induced innovation theories of intensification. We outline how the methodology employed could be used for integrating global and regional change assessments with local-level studies on farming options, adaptation to global change, and upscaling of social, environmental and economic impacts of agricultural development investments and interventions. © 2014 Elsevier Ltd.