Climate change is expected to increase extreme events such as floods, draughts and landslides. However, farmers will experience warming patterns most severely as a long term increase of uncertainty. By integrating a diverse range of crops, trees, livestock, and aquatic species farmers can build the capacity to produce a livelihood in a wider range of possible climates. Given the importance of encouraging local on-site biodiversity<!–[if supportFields]> XE “biodiversity” <![endif]–><!–[if supportFields]><![endif]–> conservation, the authors give criteria for evaluating a community’s current and potential resources to ensure agricultural biodiversity: the specific community processes which purposely or inadvertently produce agricultural diversity, the specific local actors who maintain genetic diversity, and the factors which encourage farmers to continue or abandon traditionally effective methods of seed saving. These features contribute to the relative strengths or weaknesses of a community’s food security.
Cerri, Carlos., Bernoux, Martial., Maia, Stoecio., Cerri, Carlos., 2010. Greenhouse Gas Mitigation Options in Brazil for Land-use Change, Livestock and Agriculture. Scientia Agricola 67.
Cerri et al. addressed the GHG emissions of Brazil by focusing on the mitigation potential in each of the most emitting sectors to either sink more carbon or emit less. Business as usual scenarios were projected and mitigation strategies were extrapolated to measure the potential savings of various mitigation strategies by 2020. Their accounting strategy used two formulas to measure mitigation options. The first followed the 1996 Guidelines for National Greenhouse Gas Inventories given by the International Panel on Climate Change. The second was a tool to evaluate carbon balance impacts of forestry and agriculture management on GHG emissions developed by the Food and Agriculture Organization of the United Nations. Both metrics were used to evaluate the GHG implications of the changing dynamics of forestry, agriculture and energy in Brazil.
The most significant contributer to climate change in Brazil is deforestation. The Amazon rainforest is a vast natural carbon sink. Rainforest ecosystems sequester more carbon naturally than almost any other kind. In calculating Brazil’s contribution to climate change the preservation of this forest represents the largest mitigation potential. In 2007 the Brazilian government adopted a policy which sets the goal of decreasing the rate of deforestation by 30% every set of three years. The current rate is 12,185 square kilometers per year and but considering this government goal the rate by 2020 could be less than half of the current pace. From a GHG management perspective the forests are a crucial carbon sequestration oppurtunity. Although many Brazilian forests are under heavy threat the replanting of forests is also a consideration for GHG management.
In Brazil the enteric fermentation from cattle is the third largest contributor to carbon dioxide emissions and the largest to methane gas emmissions. Brazil accounts for a quarter of the developing world’s milk production and one fifth of it’s meat production so mitigation of cattle based emissions will have relatively large impacts. There are a variety of means to reduce this source of GHG: breeding to select for breeds which emit less methane, improving productivity of meat and milk productivity so less cattle are required for the same amount of product, manure management which focuses on correctly using waste as an organic fertilizer so as to sink carbon back into the soil rather than have it be released gaseously, and the use of digestors which capture the methane from cattle and convert it into a usable fuel.
Tillage of Brazilian fields releases significant GHG. Rather than remain in the soil, carbon is released when the topsoil is turned over yearly to add fertilizer, shape beds and remove weeds. The alternative to this practice is to convert land into a no till system which allows the soil to hold more water and increase it’s stability against erosion. Tilling integrates air into deeper layers of soil stimulating microbial activity, this results in the increases decomposition of organic material which releases greater amounts of carbon from the soil. In this way previously tilled fields which have been depleted of carbon over years represent a vast potential carbon sink. There are currently 28 HA of no till land in production in Brazil and the government climate mitigation efforts aim for 40 HA of no till land by 2020.
In addition to these main sources of agricultural and forestry GHG mitigation, the paper also covered several other methods which, while not as significant individually, could also add up to large GHG reduction if all enacted effectively. These include reducing methane released from decomposing matter in flooded rice fields through better water management and increasing the sustainable production and use of bio-ethanol and biodiesel.
The authors estimated that increasing carbon sinks represent 19-39% of mitigation potential and reducing emissions represents 61-81%. Since the authors accounted for the increased use of bio fuel crops as a GHG savings for both the agriculture and energy sectors, their estimates for the mitigation potential of Brazil were even higher than that of the government.
Hoffman, Irene 2010. Climate change and the characterization, breeding and conservation of animal genetic resources. Animal Genetics 41, 32-46.
Hoffman researched the ‘growing dichotomy’ between commercial operations and small-scale pastoralists who live on the land. Since genetic diversity is considered to be an important measure of agricultural systems facing systematic shocks such as climate change, the genetic characteristics of these two types of production were examined. The commercial model is genetically narrow featuring a small number of globally distributed breeds which have been researched and distributed to many developed countries because of one productive trait. Regions which have built industrial livestock systems are the ones which have suffered the greatest loss of breed diversity in the past century. These systems are not able to quickly adjust to sensitivities from new temperature, precipitation, or disease conditions caused by climate change because they generally rely on only one breed which is specifically adapted to the existing set of conditions. The author discusses how livestock physiology and nutrition changes when temperatures rise above the animals’ adaptive range, significantly decreasing their ability to produce milk and/or meat. In the context of climate change more research is required to elaborate on this paper’s prediction that current concentrated feeding operations may face severe challenges as their animals live in different conditions. On the other hand hot arid climates in many parts of the world provide limited natural resources and only support agricultural systems like low input pastoralism. Thus, many of the world’s locally kept and bred livestock breeds already live in the types of climates which could be created or exacerbated by climate change. The people who raise local, small herd, forage livestock are generally economically and ecologically marginalized.
Since livestock bred by local people and methods will be more suited to the local environment than those imported from other countries, local herds will likely support the adaptation to climate change for rural peoples much more effectively than foreign breeds in concentrated operations. According to the author it is more important that countries develop their own genetic livestock pools than simply import them for economic reasons, however, the author suggests that should climate change make certain local livestock populations unsuited for new conditions, exchange of breeds among regions which share similar environments could be necessary. Thus climate change will increase the necessity for genetic exchange of livestock among countries. Since many of the world’s local breeds are uncharacteristic, that is not cataloged and registered internationally for their traits, it is difficult for outsiders to gauge the strengths and weaknesses of local breeds, making their potential for exchange with international livestock breeding programs poor. In order to integrate pastoral populations and rare local livestock breeds with global climate change adaptation measures, it is important to characterize local breeds and prioritize agricultural biodiversity as a key measure of climate change adaptation.
Seo, S., 2010. Is an integrated farm more resilient against climate change? A micro-econometric analysis of portfolio diversification in African agriculture. Food Policy 35, 32–40.
The data for this study was taken from a 2002–2003 growing year collection produced by the GEF/World Bank project on climate change. Countries were selected so that each region of Africa would be represented and data collection took place clustered in villages in order to make survey taking more affordable. The countries were Niger, Burkina Faso, Senegal and Ghana representing West Africa, Cameroon for Central Africa, Kenya and Ethiopia for East Africa, South Africa and Zamibia for southern Africa, and Egypt for Northern Africa. These data reflected decisions already made by farmers regarding their farm management choices in response to varying environmental factors of the preceding years. The data collectors attempted to understand how African farmers react when forced to continue profitability despite lower yields as temperature and precipitation change threaten previously profitable methods. The data on these previously executed decisions by farmers was then extrapolated to explain what farmers will do under circumstances predicted by climate change models. Of those surveyed, 7% specialized in livestock while 40% specialized in crops, making about half of the respondents specialized, and half integrated. The profitability of integrated farms was higher per hectare than it was for specialized farms, considering own food at market cost and labor costs only for hired laborers. Livestock only farms and mixed farms tended to be in hotter and drier regions, while milder areas with more precipitation featured many more crop only farmers. Areas which had access to heavy springtime stream flow tended to be crop farmers because of the available water at planting time and the potential to store water for the hotter summer, whereas farmers in regions which get more summer rains tended to have livestock only because local irrigation is less viable for planting. In addition to lands of high water flow, specialized farms tended to be in areas with electricity.
Distinct ecological and agricultural regions are diverse and plentiful in Africa. The farmers surveyed live in landscapes from high mountains to flat plains, and the resulting crop and livestock used can be quite different. Accordingly, the way that farmers adapt to climate change will also show a diversity of strategies. However the research did show that across the board, the switch to integrated farms will be profitable into the future. An increase in temperature of one degree C is expected to raise the number of integrated farms and lessen the number of either kind of specialized farm. An increase in precipitation of any amount correlates with an increase of the number of farms with any crops, be they mixed or specialized.
The research found that any significant and abrupt change in climate would be greatly harmful to African farmers, causing a possible 75% reduction in productivity. However, even under extreme climate changes, diverse farms are estimated to fare better than specialized ones. Given the predicted longterm and consistent nature of the changing climate, farmers will likely have to continue adapting their practices to new temperatures and precipitation levels. Farms which remain livestock or crop only will continue to face mounting ecological pressure to integrate as time goes on and the climate continues to change. The paper suggests that aid and government programs attempting to help farmers in the process of climate adaptation should do so with an eye toward the regional differences in ecology and policy. They also suggest that their data on adaptation was created assuming the current practice of communal land for grazing and planting, and that aid projects which alter those land use patterns would also alter the predicted results of this research.
Strzepek, K., Boehlert, B., 2010. Competition for Water for the Food System. Philisophical Transactions of the Royal Society Biological Sciences 365, 2927–2940.
Strzepek et al. identified potentially stressed agricultural regions by focusing on specific geopolitical regions and estimating likely water demands based on trends of increasing or decreasing industrial water need. The increase of both urban populations as well as the increase of a nation’s GDP correlate with dramatically increased water usage per capita, so countries which are developing larger cities and industrial economies are likely to require more water in the future. Subsurface water, the most common source for agricultural irrigation, will be placed under increasingly heavy demand as non-agricultural needs grow, thus decreased supply was considered in modeling future availability.
In order to incorporate the effects of a changing climate on already threatened agricultural water sources, the modeling methodology used three distinct climate scenarios to predict future supply; a stable unchanging climate, a generally wetter climate and a generally drier climate. In any of the scenarios, threatened areas are identified, however which areas are most challenged depends on the scenario. For instance, in Europe under the drier scenario agriculture water supply is threatened whereas in the wetter scenario it is not. Some areas, like Brazil and the U.K. are not likely to face climate change-based agricultural water shortage under either scenario.
The researchers identified a region’s likelihood for water shortage by considering how much water is currently available for agriculture, and then factored the likely increased demands from industry and urban use. Many ‘developing’ countries face a specifically difficult water management challenge. Industrial development requires increasingly large water inputs, especially as a coolant for power plants. The intensive water use of these processes diverts water away from agricultural availability. Urban residents use significantly more water. This is the result, in many developing countries, of a change from limited central sources such as a town pump, well or water truck to plumbing directly into the house. This allows for the potential of overuse in a local area as individuals use more than what is sustainable for the region as a whole. This trend also appears on a larger scale, as transnational borders dissect rivers and watersheds. In these stations certain administrative regions can overuse, creating scarcity downstream. Here, the researchers identified a shortage of appropriate agricultural water management, globally, as a cause of consistent local misuse and constructed need.
The other demand for water are Environmental Flow Requirements. These are the calculated need for flowing water in an ecosystem which is institutionally maintained in order to secure ecosystem services. The EFR of a given areas varies greatly depending on the type of ecosystem. For example Oceanian water ways require 54 percent of water, while those in the Nile river basin require 23 percent. These values are calculated to satisfy only minimum ecological requirements.