ASSESSMENT OF CLIMATE CHANGE IMPACTS AND LOCAL VULNERABILITIES Agriculture and (urban) forestry
Lorenzo Ciccarese (ISPRA)
WORKSHOP Life Project ACT - Adapting to Climate change in Time No LIFE08 ENV/IT/000436 Rome, July the 19th-20th -21st 2010
1. Introduction ........................................................................................................................................ 3 2. UNFCCC and adaptation ................................................................................................................. 4 3
Climate and atmospheric factors ................................................................................................ 4
Impacts on agriculture and forestry .......................................................................................... 6
4. Downscaling future climate change scenarios .............................................................................. 11 5. Vulnerability of Italyâ€™s agriculture and forestry to climate change ........................................ 12 2.1 Exposure ....................................................................................................................................... 15
Sensitivity ............................................................................................................................... 16
Adaptive capacity ................................................................................................................... 17
Conclusion .................................................................................................................................... 17
1. Introduction Earth‘s surface temperature has increased since 1880. During last decade global temperatures rise to the highest levels ever recorded. The Fourth Assessment Report (FRA) of the Intergovernmental Panel on Climate Change (IPCC) indicates that average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50 -year period in the last 500 years and likely the highest in at least the past 1300 years. (IPCC, 2007) Most scientists agree current global warming trend is mainly the result of carbon dioxide (CO 2) and other green-house gases (GHGs)‘ 1 levels rising in the Earth‘s atmosphere. According to data sources compiled by the National Oceanic and Atmospheric Administration (NOAA, www.co2now.org), the level of CO2 in the atmosphere is increasing at an accelerating rate from decade to decade and at the end of June 2010 was 392 parts per million (ppm). Changing of the natural GHGs is due to human activities: the burning of fossil fuels and, to a lesser extent, deforestation, forest degradation and land use changes for agriculture, industry, and other human activities. The IPCC Fourth Assessment Report concluded there's a more than 90 percent probability that human activities over the past 250 years have warmed our planet. Since then, a outstanding amount observations, experiments and models have confirmed the IPCC‘s outcomes. Climate change has been recognised as one of most serious and challenging problems we have to face as a global community in the 21 st century and it has already had clear and discernible effects on the global and local environment. Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to GHGs produced by human activities. Temperature projections depend on specific emissions scenarios. If emissions continue unabated, global mean temperatures are likely to rise by 2–6°C over the next century compared to the 1980-1999 baseline. This mean global warming will likely manifest itself over a range of spatial and temporal scales, altering mean seasonal climate, inter-annual climate variability, and the frequency and magnitude of extreme events. Such climatic changes could have a wide variety of important impacts on sectors such as human health, biological invasions, species extinctions, and water and energy resources. The extent of climate change impacts on individual regions will vary over time and with the ability of different societal and environmental systems to mitigate or adapt to change. This paper propose a preliminary conceptual framework, within Life Project ACT - Adapting to Climate change in Time,. No LIFE08 ENV/IT/000436, to assess the vulnerability of Italy‘s farming and farmers to climate change and climate variability by developing a system and comparing vulnerability indicators.
Other gases that contribute to the greenhouse (GHG) effect include: water vapour, the most abundant greenhouse gas, but importantly, it acts as a feedback to the climate; methane (CH4), a hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture (especially from rice cultivation), as well as ruminant digestion and manure management associated with domestic livestock; nitrous oxide (N2O), produced by soil cultivation practices, especially the use of synthetic and organic fertilizers, fossil fuel combustion, nitric acid industrial production, and biomass burning: three categories of synthetic compounds of entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to destruction of the ozone layer. hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphurhexafluoride (SF6). All these GHGs are weighted by their 100-year Global Warming Potentials (GWP).
2. UNFCCC and adaptation The United Nations Framework Convention on Climate Change (UNFCCC) recognizes climate change as a serious threat and assumed as a ultimate objective avoiding ‗‗dangerous interference‘‘ with the global climate system. It then asserts that ‗‖such a level should be achieved within a timeframe sufficient to allow ecosystems to adapt naturally to climate change‖. The UNFCCC, at Article 4.1, commits countries to plan for and facilitate adequate adaptation 2 to climate change. All Parties are required to take the actions necessary related to funding, insurance and the transfer of technology, to meet the specific needs and concerns of developing countries arising from the adverse effects of climate change (Article 4.8) and to take full account of the specific needs and special situations of the least developed countries in their actions with regard to funding and transfer of technology (Article 4.9). In addition, developed countries are required to assist developing countries in meeting costs of adaptation to the adverse effects of climate change (Article 4.4). In Article 4.8 of the UNFCCC, taking action to the adverse effects of climate change is referred to in conjunction with addressing the impact of the implementation of response measures, which generally refers to negative impacts resulting from the implementation of climate change mitigation activities. Current climate change negotiations have established two parallel processes (i) for further commitments on GHG reduction by industrialised countries and (ii) for long-term cooperation under the Convention (Ad-Hoc Working Group on Long-Term Cooperative Actions, AWG-LCA). The AWG-LCA‘s mandate is to focus on five key elements (building blocks) of long-term cooperation, namely mitigation, adaptation, finance, and technology and capacity building.
3. Climate and atmospheric factors The Earth‘s climate depends on the balance between the amount of energy received from the sun and the amount of energy that is absorbed or radiated back into space. Climate expresses the average weather in a given place, usually over a period of more than 30 years. It is a complex of inter-related variables. Climate patterns (namely temperature and rainfall) determine what types of animals and plants can live and reproduce in a particular place. 1. Air temperature is a key component of climate, and it can have wide-ranging effects on species, ecosystems and their productivity. Air temperature is the primary factor controlling the distribution of vegetation and it is known to strongly influence the distribution and abundance patterns of plants, due to the physiological constraints of each species. Changes in temperature can disrupt a wide range of natural processes, particularly if these changes occur abruptly and plant and animal species do not have time to adapt. Hence, changes in temperature due to climate change are expected to be one of the important drivers of change in agriculture and forest ecosystems. Physical and biological responses to changing temperatures are often better understood than those to other climate factors, and the anthropogenic signal is easier to detect for temperature than for other parameters.
The IPCC defines adaptation as the "adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities" (IPCC, 2007). The Glossary of the Fourth Assessment Report (FRA) of the Intergovernmental Panel on Climate Change (IPCC) defines ‗adaptation‘ as the grouping of ―initiatives and measures to reduce the vulnerability of natural and human systems against actual or expected climate change effects. Various types of adaptation exist, e.g. anticipatory and reactive, private and public, and autonomous and planned. Examples are raising river or coastal dikes, the substitution of more temperature-shock resistant plants for sensitive ones, etc. (http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_appendix.pdf)
This indicator examines historical records of temperature patterns (mean temperature, including daily maximum and minimum temperature) for a specific site to the entire surface of the Earth. This indicator shows annual anomalies, or differences, compared with the average temperature from 1901 to 2000. The indicator can be integrated with others (namely precipitation) to construct specific indexes. An increase in average temperature can: lengthen the growing season in regions with a relatively cool spring and fall (in higher latitudes and altitudes in Italy); adversely affect crops in regions where summer heat already limits production; increase soil evaporation rates, and increase the chances of severe droughts. 2. Precipitation patterns can have wide-ranging effects on ecosystems. Rainfall, snowfall, and the timing of snow-melt can determine what types of animals and plants (including crops) can survive in a particular place and shape the amount of water available for irrigation. Changes in precipitation can disrupt a wide range of natural processes, particularly if these changes occur abruptly and plant and animal species do not have time to adapt. 3. Changes in the frequency and severity of extreme events, like heat waves, drought, floods and hurricanes, remain a key uncertainty in future climate change. Such changes are anticipated by global climate models, but regional changes and the potential affects on agriculture are more difficult to forecast. Climatic variability (especially variability of precipitationâ€”in time, space, and intensity and number and severity of extreme eventsâ€”will make agriculture increasingly unstable and make it more difficult for farmers to plan what crops to plant and when. 3.1. A heat wave is a prolonged period of abnormally hot weather. With an overall warming of the Earthâ€˜s climate, heat waves are expected to become more frequent, longer, and more intense in places where they already occur. Increased frequency and severity of heat waves can lead to reduction in productivity of crops and livestock, and can lead to heavy demands for irrigation. While there is no universal definition of a heat wave, this indicator defines a heat wave as a 4-day period with an average temperature that would only be expected to occur once every 10 years, based on the historical record. 3.2. Drought conditions can affect many aspects of society, including agriculture and forestry. The impacts on agriculture vary depending on the type, location, intensity, and duration of the drought: from slowed plant growth to severe crop losses, or more demand for irrigation water. Lower stream flow and ground water levels can also harm plants and animals, and dried-out vegetation increases the risk of fires. Meteorologists generally define drought as a prolonged period of dry weather caused by a lack of precipitation, which results in a serious water shortage for some activity, group, or ecological system. Drought can also be thought of as an imbalance between precipitation and evaporation. 4. Increasing atmospheric CO2 levels can act as a fertilizer and enhance the growth of some crops such as wheat, rice and soybeans. CO 2 can be one of a number of limiting factors that, when increased, can enhance crop growth. Other limiting factors include water and nutrient availability. While it is expected that CO 2 fertilization will have a positive impact on some
crops, other aspects of climate change (e.g., temperature and precipitation changes) may temper any beneficial CO2 fertilization effect (IPCC, 2007). Higher levels of tropospheric ozone limit the growth of crops. Since ozone levels in the lower atmosphere are shaped by both emissions and temperature, climate change will most likely increase ozone concentrations. Such changes may offset any beneficial yield effects that result from elevated CO2 levels (CO2 fertilisation). 5. Higher levels of ground level (tropospheric) ozone limit the growth of crops and cause severe effects on leaves and other organs of the crop and forest plants. Since ozone levels in the lower atmosphere are shaped by both emissions and temperature, climate change will most likely increase ozone concentrations. Such changes may offset any beneficial yield effects that result from elevated CO2 levels. Change in climatic variability and extreme events: Changes in the frequency and severity of extreme events remain a key uncertainty in future climate change. Such changes are anticipated by global climate models, but regional changes and the potential affects on agriculture are more difficult to forecast.
4. Impacts on agriculture and forestry Measured Long-term data reveal recent rate of climate change is already affecting a wide variety of flora (and fauna) organisms in many parts of the world, particularly by shifts in the normal patterns of temperature and humidity, the two most important factors that that generally delimit species boundaries. The observed impacts include northward and altitudinal range shifts of flora. Scientists assume that each 1 째C of temperature increase in the northern emisphere moves ecological zones by about 125 km northward 125 m higher in altitude to find a suitable climatic regime. Mediterranean-type ecosystems, such as maquis and garigue, are especially sensitive, as increased temperature and drought favour development of desert and grassland. Climate change is also affecting timing of growth stages (i.e., phenological changes), especially the earlier onset of spring events, and extension of the growing season. Changes in abundance of certain species, including limited evidence of a few local disappearances, and changes in community composition over the last few decades have been attributed to climate change. Changes in crop phenology provide important evidence of responses to recent regional climate change. Such changes are apparent in perennial crops, such as fruit trees and wine-making varieties of grapes, which are less dependent on yearly management decisions by farmers than annual crops and are also often easier to observe. Phenological changes are often observed in tandem with changes in management practices by farmers. A study in Germany (Menzel et al., 2006c) has revealed that between 1951 and 2004 the advance for agricultural crops (2.1 days/decade) has been significantly less marked than for wild plants or fruit trees (4.4 to 7.1 days/decade).All the reported studies concern Europe, where recent warming has clearly advanced a significant part of the agricultural calendar. The extension of the growing season has contributed to an observed increase in forest net primary productivity (NPP) in temperate regions, while warmer and drier conditions are partly responsible for reduced forest productivity, increased forest fires and pests and pathogens in the Mediterranean Basin. Forestry in Europe has shown vulnerability to recent trends in heat-waves, droughts and floods. Scenario
A multitude of studies based on field experimental research, combination of ecological modelling with different climate change scenarios and process modelling affirm that the responses of forests to climate change trends across Europe may be considerable (a limit is downscaling). Impacts of climate change will become increasingly evident, interacting with the effects of land-use, biotic exchange, and pests and diseases. Forest area (forest-tundra and dark-needled taiga type) is expected to expand in the North on bare lands or tundra, decreasing dramatically the current tundra area by 2100. Forest area is assumed to contract in the South. Native coniferous forests are likely to be replaced by broadleaved forests in western and central Europe. Distribution of archetypal European species as common oak (Quercus robur) and sessile oak (Quercus petraea) will be relatively unaffected by climate change, as on their ability to ‗track‘ shifting climate through colonizing new territory, or to modify their physiology and seasonal behaviour (such as period of flowering or mating) to adapt to the changed conditions where they are. Other species‘ distribution will be significantly affected, such as Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and many other temperate and boreal trees. These species‘ distributions should contract substantially with climate change, with migration northward being limited by the sea. A third category of species‘ distribution will be very much affected by climate change and this is mainly Mediterranean and temperate species such as European larch (Larix decidua) and silver fir (Abies alba), European black pine (Pinus nigra) and maritime pine (Pinus pinaster). These species should disappear from most of their present distributions. In Europe, the new colonisable areas may be for some species disconnected from the present ones (Pinus nigra, Pinus pinaster). The distribution of a number of typical tree species is likely to decrease in the Mediterranean. A 2005 study carried out by Thuiller et al., in projecting late 21st century distributions for 1,350 European plants species under seven climate change scenarios, showed that many European plant species could become severely threatened and more than half of the species studied could be vulnerable or threatened by 2080. Despite the coarse scale of the analysis, species from mountains could be seen to be disproportionably sensitive to climate change (60% species loss), since the narrow habitat tolerances of the mountain flora, in conjunction with marginal habitats for many species. The boreal region was projected to lose few species, although gaining many others from immigration. The southern Mediterranean and part of the Pannonian regions have a negative residual for species loss. Both regions are characterized by hot and dry summers and are occupied by species that tolerate strong heat and drought. These species are likely to continue to be well adapted to future conditions. Tree vulnerability will increase as populations/plantations are managed to grow outside their natural range. In northern Europe, climate change will significantly alter phenology (budburst, flowering, fruit maturation, leaf coloring, …). Data on trends in phenology in European species have been collated under the COST Action 725 ‗Establishing a European data platform for climatological applications. A meta-analysis of this data has shown that the phenology of the species studied is undoubtedly responsive to temperature and that the patterns of observed changes in spring match the measured national warming across 19 countries. In northern Europe, climate change will increase net primary productivity (NPP) and biomass of agriculture and forests. In the boreal forest, soil CO 2 fluxes to the atmosphere increase with increased temperature and atmospheric CO 2 concentration, although many uncertainties remain. Climate change may induce a reallocation of carbon to foliage and lead to carbon losses. Photosynthesis and respiration of plants and microbes increase with temperature, especially in temperate latitudes. As respiration increases more with increased temperature than does 7
photosynthesis, global warming is likely to increase the flux of CO2 to the atmosphere which would constitute a positive feedback to global warming. There are two major forms of extreme temperature stress on crops - heat and cold. An increase in global temperatures may have either or both of these two acute effects: more frequent high temperature stress and less frequent cold temperature stress. Increase in temperature will lengthen the effective growing season in areas where agricultural potential is currently limited by cold temperature stress. Thus, increased temperature will cause a poleward shift of the thermal limits to agriculture. This poleward shift will be especially important for crops that have tropical centres of origin and adaptation but are also grown in temperate latitudes during warm seasons. Italyâ€˜s mountain flora will undergo major changes due to climate change. Three responses to climate change can be distinguished at the species level, namely genetic adaptations, biological invasions through species inter-competition, and species extinction. Change in snow-cover duration and growing season length should have much more pronounced effects than direct effects of temperature changes on metabolism. Overall trends show increased growing season, earlier phenology and shifts of species distributions towards higher elevations. The tree-line is predicted to shift upward by several hundred metres. These changes, together with the effect of abandonment of traditional alpine pastures, will restrict the alpine zone to higher elevations, severely threatening nival flora. The composition and structure of alpine and nival communities are very likely to change. Mountain regions may additionally experience a loss of endemism due to invasive species. Similar extreme impacts are expected for habitat and animal diversity as well, making mountain ecosystems among the most threatened in Europe. Another major problem in many parts of the European Alps is that ecosystems have been so fragmented and the population density is so high, that many options for ecosystem conservation may be impossible to implement. More important than acute effects of extreme temperature stress are the chronic effects of continuously warmer temperatures on crop growth and development. Chronic effects of high temperature include effects on grain growth discussed above. Record crop yields clearly reflect the importance of season-long effects on crop yields: crops generally yield the most where temperatures are cool during growth of the harvested component. Increased temperature would also affect the crop calendar in many regions. In the South global warming is likely to reduce the length of the effective growing season (with a longer period of quiescence in warmer days). In semi-arid regions and other agro-ecological zones where there is wide diurnal temperature variation, relatively small changes in mean annual temperatures could markedly increase the frequency of highest temperature injury. Thus, global warming would reduce dry matter accumulation in some crops, because of increased respiration, and reduced photosynthesis and cellular energy. Climate change will continue to alter the chemical composition and density of wood while impacts on wood anatomy remain undefined. In the northern and maritime temperate zones of Europe, and at higher elevations in the Alps, NPP is likely to increase throughout the century. However, by the end of the century in continental central and southern Europe, NPP of conifers is likely to decrease due to water limitations. Water use efficiency in plants may increase due to the fertilisation effect of increased atmospheric CO2 concentrations, but in some parts of Europe, leaf area and associated evapotranspiration from forests may increase, resulting in decreased water flow from forests. Negative impacts of drought on deciduous forests are also likely. Water stress in the south may be partially compensated by 8
increased water-use efficiency, elevated CO2 and increased leaf area index, although this is currently under debate. Plant physiological responses, including growth responses to increased atmospheric CO2 and changes in water use efficiency, are expected to ameliorate the response of some plant functional types to climate change. On the other hand, nitrogen deposition, the enhanced potential for invasion by exotic species (that may benefit more than slower growers in more productive environments) or the promotion of more competitive native species may change competition in plant communities, yielding novel patterns of dominance and ecosystem function. Abiotic disturbances for forests are likely to increase, although expected impacts are regionally specific and will be substantially dependent on the forest management system used. A substantial increase in wind damage is not predicted. In northern Europe and in the Alps, snow cover will decrease, and soil frost-free periods and winter rainfall increase, leading to increased soil waterlogging and winter floods. Warming will prevent chilling requirements from being met, reduce cold-hardiness during autumn and spring, and increase needle loss and reduce seed reproductive success. Frost damage is expected to be reduced in winter, unchanged in spring and more severe in autumn due to later hardening, although this may vary among regions and species. Warmer temperatures, combined with increase of soil aridity and abandonment of forest management, appear to be increasing fire frequency and severity, duration and intensity of the wildfire season in the Mediterranean, and lead to increased dominance of shrubs over trees. Fire danger is likely to also increase in central, eastern and northern Europe. This, however, does not translate directly into increased fire occurrence or changes in vegetation. In the forest-tundra ecotone, increate frequency of fire and other anthropogenic impacts is likely to lead to a long-term (over several hundred years) replacement of forest by low productivity grassy glades or wetlands over large areas. The range of important forest pests may expand northward, but the net impact of climate and atmospheric change is complex. Agriculture in Italy, as well as in other industrialized countries is expected to be less vulnerable to climate change than in developing nations, where farmers may have a limited ability and resources to adapt. In addition, the effects of climate change on Italian agriculture will depend not only on changing climate conditions, but will also depend on the agricultural sector's ability to adapt through future changes in technology, changes in demand for food, and environmental conditions, such as water availability and soil quality. Management practices, the opportunity to switch management and crop selection from season to season, and technology can help the agricultural sector cope with and adapt to climatic variability and change. In this regard the role of research is a critical factor. Climate change threatens the assumption of static species ranges which underpins current conservation policy. The ability of countries to meet the requirements of EU Directives and other international conventions is likely to be compromised by climate change, and a more dynamic strategy for conservation is required for sustaining biodiversity. Moderate climate change will likely increase yields of North Italy rain fed agriculture, with significant spatial variability. Climate change is expected to improve growing conditions for some crops that are limited by length of growing season and temperature (e.g. fruit production in the subAlpine region). Crops in south Italy are expected to be particularly vulnerable, especially those that are currently near climate thresholds (e.g., wine grapes in Sicily and Salento) are likely to suffer decreases in yields, quality, or both. High quality â€•territorialâ€– food produces, that are produced almost exclusively in a narrow climatic range characterised by a lack of both extreme heat or cold, may suffer important impacts from (even moderate) climate changes. The area available for grapewine production is likely to decline, especially because of extreme temperatures in the growing season. 9
In addition to destroying crops, storms can also deteriorate land quality and production potential. Storm surges can flood coastal areas with saline water, resulting in salinity of agricultural land. If the surge occurs after the main rainy season, effects on cropping and yields are greater as the salt is not quickly diluted. Deposition by floods of a layer of alluvium on cultivated land may bury crops and change soil quality. This process may actually improve soil quality and yields in subsequent years. But the crop production potential may be lowered if the deposits are rather infertile and drought-prone sandy matter, or silts which may initially be saturated and inhospitable to plant roots and soil organisms. In some areas, good topsoil may be washed away, exposing less cultivable soil layers. The impact of a storm on the soil depends on the preceding climatic conditions (soil moisture, water level). It is also affected by factors such as topography and soil type, including soil depth, moisture holding and drainage capacity. Impacts also depend on land-use and farming practices that influence the organic matter content and permeability of the soil. The richer and more permeable the soil, the less likely it is to be washed away during a storm. Practices such as levelling, terracing, puddling, drainage and irrigation help to manage water flow and hold soil in place during storms and floods. Deep-rooting plants such as trees and shrubs may also be planted to provide more stability. Storms can all affect forest resources, directly through the impact of high winds, which destroy trees, or indirectly through flood damage which affect forest health and growth (forests in Po valley). Flood-stressed trees are prime targets for attack by secondary organisms including certain root and collar-rot diseases favoured by waterlogged, oxygen-deficient soil conditions, in conjunction with mould fungi, Phytophthora spp. and Pythium spp. Severe storms can influence fuel wood availability. Although little information is available on specific cases, forests play a role in mitigating storm impact through various means including windbreaks, buffer zones, agro-forestry systems, mangroves, and other coastal forests. It is generally believed that forest clearing and forest fires was a contributing factor to the extensive damage from quite a few recent floods in Italy. More tree windbreaks surrounding and within plantations would have substantially reduced the damage and economic loss. Box 1 Premium wine making is confined to regions climatically favourable to growing grapes with balanced composition and varietal typicity. A delicate balance among several climatic factors is essential. Wine-grapes are known to be highly sensitive to climatic conditions, especially temperature (e.g., viticulture was thriving inEngland during the last medieval warm period). They have been used as an indicator of observed changes in agriculture related to warming trends, particularly in Europe and in some areas of North America. The date of grape harvest has changed to warming trends, related to warming trends, particularly in Europe and in some areas of North America. The Observatoire National sur les Effets RĂŠchauffement Climatique uses harvest dates in the vineyards of Champagne as an indicator to measure climate change. Now, there is large scientific evidence that climate change is having profound negative impacts on premium wines, including Italian ones. The fact is that climate change is altering grape plant phenology, from flowering to ripening. 10
Most French premium wines end up having higher sugar levels and alcohol content while retaining less acids - which means they are unbalanced with an overripe flavour and heavier texture. Since 1989 harvest dates have crawled gradually backwards and the 2007 harvest started on August 20. By comparison, in 1945, the harvest commenced on September 8 and the 1947 harvest started on September 2, whilst harvests in the late 1980s were in early October. These changes put France‘s ‗wine producing pedigree‘ at risk. France‘s most prominent sommeliers and chefs joined to urge the French government to push for a strong global agreement at the latest UNFCCC conference in Copenhagen, warning that failure to curb greenhouse gases would devastate their sector.
5. Downscaling future climate change scenarios In order to enhance our understanding of climate and climate change, super-computers runned by climatic research centres over the world perform General Circulation Models (GCMs). Currently, more than a couple of dozen GCMs, each with different parameterization, arew being developed around the globe. Their results were also made available to the IPCC FAR (IPCC, 2007) and outputs have been produced for the different SRES emission scenarios: A1B, A2 and B1. There are marked differences between different models, including the selection of numerical methods, the spatial resolution of the simulation, and the subgrid-scale parameters. With a certain level of accuracy, a GCM reproduces mass and energy fluxes and storages that occur within the atmosphere, by using an analysis unit. This unit is often called a ―cell‖, which cannot be unlimitedly small, as it is restricted to a size of 100-300 km. Thus, although the sizeable efforts done by climate modelling centres, GCM outputs are still too coarse for assessment of impacts on biodiversity, ecosystem services, agricultural and forestry systems, species distributions, conservation planning and other landscape and agriculture related matters. (This is particularly true for countries like Italy characterised by a complex orography and local climates that may not respond in the same way as regional-scale climates estimated from coarse-grid general circulation models.) Due to that, the so-called downscaling techniques have been developed to obtain regional predictions of climatic changes, ranging from smoothing and interpolation of GCM anomalies, to neural networks, and regional climate modelling. The different downscaling techniques vary in accuracy, output resolution, computational and time requirements, and also on climatic science robustness. Regional Climate Models (RCM) provide 20 to 50km surfaces by re-modeling GCM outputs and are thus only applicable to a limited number of GCMs (for which boundary conditions are available), and require a considerable processing capacity, time and storage for obtaining a single scenario-by-period output, thus making it barely feasible to get RCM outputs to be used by agricultural and forestry researchers and managers. Statistical downscaling, on the other hand, provides an easy to apply and much rapid method for developing high resolution climate change surfaces for high resolution regional climate change impact assessment studies. However, it tends to reduce variances (and thus alter uncertainties) and to cause a wrong perception of higher accuracy, while in point of fact it only provides a smoothed surface of future climates. For that reason, qualitative changes in potential production may well be estimated on the basis of the scenarios, but quantitative changes in the actual production, including the limitations caused by the changed variability of weather variables, such as daily and seasonal amplitudes of temperatures, seasonal patterns in precipitation, cloudiness, remain difficult to estimate.
Present knowledge does not allow a firm statement to be made concerning a future situation with respect to water-limited agricultural production. At a regional production level the available quantitative data from regionalised GCMs are generally inadequate to be used as direct inputs for crop growth models. At a global level the simultaneous changes in rainfall pattern, air humidity and possible shifts in vegetation zones add to uncertainty, as many and often non-linear feedbacks are expected to operate.
6. Vulnerability of Italy’s agriculture and forestry to climate change Chapter 17 (Assessment of adaptation practices, options, constraints and capacity, http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter17.pdf ) of the IPCC FAR defines vulnerability as the degree to which geophysical, biological and socio-economic systems are susceptible to, and unable to cope with, adverse impacts of climate change. Chapter 19 (Assessing key vulnerabilities and the risk from climate change, http://www.ipcc.ch/pdf/assessmentreport/ar4/wg2/ar4-wg2-chapter19.pdf) identifies seven criteria that may be used to identify ‗key‘ vulnerabilities. They are: magnitude of impacts, timing of impacts, persistence and reversibility of impacts, likelihood (estimates of uncertainty) of impacts and vulnerabilities, and confidence in those estimates, potential for adaptation, distributional aspects of impacts and vulnerabilities, importance of the system(s) at risk. According to the IPCC FAR, a region‘s vulnerability to climate change and variability is described by three elements: exposure, sensitivity, and adaptive capacity, as follows: Exposure can be interpreted as the direct danger (i.e., the stressor), and the nature and extent of changes to a region‘s climate variables (e.g., temperature, precipitation, extreme weather events). Sensitivity describes the human–environmental conditions that can worsen the hazard, ameliorate the hazard, or trigger an impact. Adaptive capacity represents the potential to implement adaptation measures that help avert potential impacts. The framework for vulnerability as described above is presented in Figure 1. Exposure and sensitivity are intrinsically linked and together affect potential impact. To assess farming vulnerability to climate change, we look at exposure to climate change, sensitivities to those changes, and societal coping and adaptive capabilities (which might integrate mitigation options). The vulnerability indicator approach is integrated, in the sense that the indicators identified should embody both the biophysical conditions of the farming regions and the socio-economic conditions of the farmers. Box 1 The concept of vulnerability, which has its origins in geography and natural hazards research, has gained increasing importance within the global change (including climate change) agenda. Vulnerability is conceptualized in different ways across different disciplines and has been equated to concepts such as resilience, risk, marginality, adaptability, and exposure. The climate change literature provides two main distinct epistemological approaches to conceptualizing vulnerability. One approach views vulnerability as the ―end point,‖ in terms of potential for negative consequences that are difficult to ameliorate through adaptive measures given the range of possible climate changes that might occur. In this approach, vulnerability is understood as a residual of climate change impacts minus adaptation; it is therefore the net impact of climate change. This approach emphasizes the physical dimensions of vulnerability. In this approach, assessment of vulnerability is the end point of an analytic
sequence that begins with projections of future emission trends, moves on to the development of climate scenarios, and then progresses through biophysical impact studies and the identification of adaptive options. Thus, the end point represents a strong scientific understanding of climate change and other environmental problems. An assumed knowledge of future climate is deeply embedded in end-point analyses in terms of both impacts and adaptations. The second approach considers vulnerability as the ―starting point,‖ i.e. as a state that exists within a system before it encounters a hazard event. Vulnerability is determined by the internal properties of a system, and is a variable condition generated by multiple environmental and social processes, including climate change. Vulnerability depends on the context; the factors that make a system vulnerable to a hazard will depend on the nature of the system and the type of hazard in question. Thus, the starting point approach diagnoses inherent social and economic processes of marginalization and inequalities as the causes of climate vulnerability, and seeks to identify ways to address these processes (O‘Brien et al. 2004a). As viewed through the starting point approach, the inability to cope with or adapt to climate variability and change may be termed ―social vulnerability,‖ since we are concerned about social systems. In an effort to find a compromise between these two approaches, some scholars have proposed the use of nested flow charts that show how social and environmental factors interact to create situations vulnerable to sudden changes.
Defining an area as vulnerable is, thus, not a prediction of negative consequences of climate change; it is an indication that across the range of possible climate changes, there are some climatic outcomes that would lead to relatively more serious consequences for the region than for other regions. Moderate climate change will likely increase yields of Northern Italy‘s rain fed agriculture. Some studies project likely climate-related yield increases of 5-20 percent over the first decades of this century, with the overall positive effects of climate persisting through much or all of the 21st century. Agriculture in Italy, and other industrialized countries, is expected to be less vulnerable to climate change than agriculture in developing nations, especially in the tropics, where farmers may have a limited ability to adapt. In addition, the effects of climate change on U.S. and world agriculture will depend not only on changing climate conditions, but will also depend on the agricultural sector's ability to adapt through future changes in technology, changes in demand for food, and environmental conditions, such as water availability and soil quality. Management practices, the opportunity to switch management and crop selection from season to season, and technology can help the agricultural sector cope with and adapt to climatic variability and change.
Figure 1. Vulnerability framework. Source: International Food Policy Research Institute
Particular attention is paid to the underlying socioeconomic and institutional factors that determine how farmers respond to and cope with climate hazards. Farmer or farm sector vulnerability may be measured in terms of impact on profitability or viability of the farming system. Farmers with limited financial resources and farming systems with few adaptive technological opportunities available to limit or reverse adverse climate change may suffer significant disruption and financial loss for relatively small changes in crop yields and productivity or these farms may be located in areas more likely to suffer yield losses. Farmers from semi-arid and cool temperate and cold agricultural areas as those that might be more clearly affected by climate change and climate variability. Regional economic vulnerability reflects the sensitivity of the regional or national economy to farm sector and climate change impacts. A regional economy that offers only limited employment alternatives for workers displaced by the changing profitability of farming and other climatically sensitive sectors may be relatively more vulnerable than those that are economically diverse. In Italy, the areas of the South that are more dependant on agriculture are more exposed, as increasing aridity is expected in this region under climate change and thus it was considered to be potentially more economically vulnerable than other regions in Italy. 14
Given the diverse currently existing conditions, the geographical variation likely to exist in any climate change scenario, and the wide uncertainty that must be associated with local prediction of future climates, some vulnerable agricultural areas and populations likely exist for nearly every region even if the expected value for the region is a net benefit. This makes vulnerability a relative concept - while there may be a few areas where even the most extreme climate change we can imagine would not generate losses, in general, the problem is to consider whether a particular region or population is relatively more vulnerable than others. Below here it is presented a selection of indicators. The selection is only temptative and needs to be assessed in relation to data availability. Potential indicators are: Utilised Agricultural Area (UAA) (%)* Cropland (% of UAA)* Irrigated (% of UUA)* Land area (ha) Climate (temperature, precipitation) GNP/pro capite** Annual growth** Annual Growth. (% of GDP)** *Agricultural land includes grazing and cropland, reported as a percentage of total land area. Cropland is reported as a percentage of agricultural land. Irrigated area is reported as a percentage of cropland. ** GNP is in Euro; annual growth, per cent per annum. Precipitation and temperature may used significantly in an assessment of vulnerability. Regions that are more likely to be limited by low temperatures and thus warming may prove beneficial - these areas may still suffer if precipitation changes are adverse. But, further warming is unlikely to benefit already warm regions. Thus, global warming appears somewhat stacked against the already warm areas, like the ones involved in the Life project. Coincidentally (or not), warmest regions in EU tend to also be among the EU poorest. 2.1 Exposure Exposure relates to the degree of climate stress upon a particular unit of analysis; it may be represented by either long-term changes in climate conditions or changes in climate variability, including the magnitude and frequency of extreme events. In this paper, exposure is represented by two elements: Frequency of climate extremes: In South Italy, one of the key restraint to agriculture is a high climate variability that has historically included numerous droughts and floods and climaterelated biotic and abiotic stresses (forest fire, etc.). In regions with a higher frequency of droughts or floods, crop production is more risky. Predicted change in temperature and rainfall by 2050: This metric gives the predicted level of climate change that regions will experience. The larger the changes, the more difficulty the regions are expected to have in adjusting to these changes. More importantly, if increased temperature and decreased rainfall are predicted we would expect to see negative impacts on farm production in already hot and water-scarce regions. In this regard, crops that are currently
near the thresholds for both climate variables (e.g., wine grapes in Sicily or Salento) are likely to suffer decreases in yields, quality, or both. The production of an exposure map based on the two or more elements could be provided by public stakeholders (i.e. municipality, region, province, district) trough their planning and urbanisation instruments. 2.2 Sensitivity Sensitivity, in its general sense, is defined as the degree to which a system is modified or affected by an internal or external disturbance or set of disturbances. For the scope of this contribution, sensitivity is the degree to which a system is affected, either adversely or beneficially, by climate variability or change3. The effect may be direct (e.g., a change in crop yield in response to a change in the mean, range, or variability of temperature) or indirect (e.g., damages caused by an increase in the frequency of coastal flooding due to sea level rise) This measure, which herein reflects the responsiveness of a system to climatic influences, is shaped by both socio-economic and ecological conditions and determines the degree to which a group or community will be affected by environmental stress. It is impossible to directly predict crop yields and forest productivity under potential future climates on a decadal timescale. This may only be done through crop simulation models, which are complicated because they deal with the complex physiological relationships between crop, forest and climate. Moreover, crop models are ecology- and management-sensitive. Because each crop requires extensive experiments for successful modeling, such models have only been developed thus far for major crops. Also, due to the cost implications of the necessary experiments and the location specificity of the models, the developed models can only be applied to a few locations. For aggregate analyses, inferences must be made from relatively few sites and crops, and then applied to large areas and diverse production systems. In South Africa, only the CERES-maize model has been widely applied (Schulze et al. 1993; Du Toit et al. 2002). Five indicators of vulnerability may be used to embrace factors that may influence the sensitivity of agriculture and forestry in a region: Irrigation rate: If we compare two agricultural regions that grow the same crops and have similar climates, their exposure to climate variability might be similar, but their sensitivity could be very different. For example, an irrigated system would have low sensitivity to short-term precipitation variability, whereas a rainfed system would have greater sensitivity to the same exposure. Land degradation index: Land degradation reduces the productive capacity of land. Contributors to land degradation include natural disasters and human activities (e.g., agricultural misconduct, overgrazing, industry and urbanization). This indicator represents the â€•combined degradation index,â€– which considers soil degradation (erosion, salinisation and acidification) and vegetation degradation (loss of cover and changes in species composition, biotic exchange, alien plant invasions, and deforestation). Areas with higher land degradation indices will experience greater negative impacts of climate variability and change. 3
This concept of sensitivity is not to be confused with climate sensitivity (http://www.ipcc.ch/pdf/assessmentreport/ar4/syr/ar4_syr_appendix.pdf) .
Crop diversification index: Farmers themselves commonly identify diversification as an effective strategy for managing agriculture business risks, particularly climatic and climaterelated risks. An agricultural region with more diversified crops will be less sensitive to climatic variations. Percent small-scale: Small-scale farmers are more sensitive to climate change and variability because they have less capital-intensive technologies and management practices. Thus, a region with a large number of small-scale farmers will be more climate-sensitive than a region with fewer small-scale farmers. Rural population density: The ratio of the indicator is that a region with high population density is more sensitive to climate because more people are exposed and therefore the region will need greater assistance. 2.4 Adaptive capacity The adaptive capacity of a system or society reflects its ability to modify its characteristics or behavior in order to better cope with (existing or announced) external stresses and changes in external conditions. Adaptive capacity is a significant factor in characterizing vulnerability. In the climate change context, adaptive capacity is closely related to a series of other commonly used concepts such as adaptability, coping ability, management capacity, stability, robustness, flexibility, and resilience. The IPCC describes adaptive capacity as the whole of capabilities, resources and institutions of a country or region to implement effective adaptation measures. Biological systems have an inherent resilience4 or adaptive capacity to changes in environmental conditions, the ability of a species to become adapted (i.e., to be able to live and reproduce) to a certain range of environmental conditions as a result of genetic and phenotypic responses. However, given the rapid rate of projected climate change, inherent adaptive capacity of biological systems is likely to be exceeded. Furthermore, the ability of these systems to adapt to climate change is severely limited by the effects of urbanization and settlements, barriers to migration paths, and fragmentation of ecosystems, all of which have already critically stressed ecosystems independent of climate change itself. Analyzing vulnerability of agriculture and forestry involves identifying not only the threat, but also the â€•resilience,â€– which represents the ability of an ecological system to absorb disturbances while retaining the same basic structure and ways of functioning, the capacity for self-organisation, and the capacity to adapt to stress and change. Figure 2. The aggregation of the different indicators towards the overall vulnerability. Source: International Food Policy Research Institute
The ability of a ecological system to absorb disturbances while retaining the same basic structure and ways of functioning, the capacity for self-organisation, and the capacity to adapt to stress and change.
1. Conclusion All climate-sensitive systems of society and the natural environment, including agriculture and forestry and natural ecosystems, will need to adapt to a changing climate or possibly face diminished capability to provide ecosystems services, including outdoor recreational activities, water quality, wildlife and carbon sequestration. Agriculture and forestry economic losses from climate variations and extremes events are substantial. These losses indicate that crop and forest systems are vulnerable and that adaptation has not been sufficient to offset damages associated with current variations in climatic conditions. Thus, for forest and agricultural systems adapting to or coping with climate change will become necessary, especially in certain regions of Italy where climate change scenarios demand adaptation to temperatures increases, changing amount of available water, increased frequency and intensity of extreme weather events and rises in sea level and saline intrusion in the coastal zones of the peninsula and islands. Farm level analyses have shown that large reductions in adverse impacts from climate change are possible when adaptation is fully implemented. Future crop and forest systems, including boulevards and parks, will have to be better adapted to abiotic (such as drought and salinity) and biotic (pests and deseases) stresses. Two main types of adaptation are autonomous and planned adaptation. Autonomous adaptation is the reaction of, for example, a farmer to changing precipitation patterns, in that s/he changes crops or uses different harvest and planting/sowing dates. Planned adaptation measures are conscious policy options or response strategies, often multisectoral in nature, aimed at altering the adaptive capacity of the agricultural system or facilitating specific adaptations. For example, deliberate crops 18
selection and distribution strategies across different agriclimatic zones, substitution of new crops for old ones and resource substitution induced by scarcity. Short-term adjustments are seen as autonomous in the sense that no other sectors (e.g. policy, research etc.) are needed in their development and implementation. Long-term adaptations are major structural changes to overcome adversity such as changes in land-use to maximize yield under new conditions; application of new technologies; new land management techniques; and water-use efficiency related techniques. However, adaptation is a risk-management strategy that has costs and is not fail-safe. The effectiveness of any specific adaptation requires consideration of the expected value of the avoided damages against the costs of implementing the adaptation strategy. In this regard, the future dimensions of climate change is relevant (as well as the interaction with other pressures). There are significant restrictions and barriers to biological systemsâ€˜ adaptation to climate change, such as environmental, economic, informational, social, and behavioural barriers, that are not fully understood. In addition, there are significant knowledge gaps for adaptation as well as impediments to flows of knowledge and information relevant to adaptation decisions. These limits are more evident when putting in practice local adaptation strategies. In this respect the role of research and extension institutes, indicating for example a new plant-growing list that focuses on plants that can thrive in altered climates or developing new methods of producing planting stock for forestry or amenity purposes that can tolerate the altered climate, is essential. Decision makers should take up adaptation measures that are able to incorporate biodiversity conservation and mitigation planning, to obtain â€—win-win-winâ€˜ strategies. Examples are: Changes to biological systems management that make more resilient ecosystems to climate change also increase carbon sequestration and water retention and reduce public expenditures. Inclusion of more green spaces in urban areas can play a role in urban adaptation by reducing heat stress and improving drainage during times of floods. Tree planting reduces summer air conditioning demand (while increase heating energy use by intercepting winter sunshine from tree shade is not a big problem in large part of Italy). Lowered air temperatures and wind speeds from increased tree cover can decrease both cooling and heating demand. Air conditioning and heating savings result in reduced GHG emissions from power plants. Assessment of vulnerability is key. In this respect, vulnerability has three components: exposure, sensitivity, and adaptive capacity. The environmental and socio-economic indicators to be identified have to reflect these three components of vulnerability. The approach to be followed should combine exposure with sensitivity to give the potential impact, which is then compared with the adaptive capacity to yield an overall measure of vulnerability. Principal component analysis has to be used to generate weights for the different indicators, and an overall vulnerability index has to be proposed.
Agriculture and (urban) forestry