Adapting to Climate Change: Series of Impacts
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ORGANIZATION OF AMERICAN STATES ORGANIZATION POLICY SERIES NUMBER 12 – December 2007 effects including drought, fires, and increased carbon releases into Third, the complex relationship among deforestation, changing the atmosphere because of forest die-back. (Wara et al. 2005) surface water temperatures, decreased (or increased) rainfall POLICY SERIES NUMBER 12 – December 2007 A relatively modest drop in average annual rainfall could bring patterns and other factors makes it necessary to apply general about changes in average forest moisture levels. Drier forests circulation models (GCMs) that estimate dynamic interactions will return less moisture to the atmosphere and less moisture will within wider freshwater basins. Although most climate models in turn lead to lower annual average rainfall, which will have a tend to be static, there have been remarkable advances in recent Adapting to Climate Change: series of impacts. years, and these advances will be integrated into the Amazon, 1 La Plata and other projects. One of the unique features of the Amazon region is that its forest Challenges to Freshwater Management ecosystem is responsible for roughly half of the region’s total Finally, detailed assessments of climate change impacts as the rainfall. Although the rates of deforestation appear to have slowed first step towards climate adaptation are technically complex and n recent years, the climate change debate has evolved. The Dialogue on Water and Climate, which was supported by the since a peak in 2005, deforestation remains a key driver of changing potentially expensive. Several assessments such as the recently Formerly the debate focused on verifying the scientific Government of the Netherlands and complemented ongoing precipitation. This decline in average rainfall is forecasted to completed vulnerability mapping of the wider harbor area of Ievidence regarding the causes and consequences of work of the Organization of American States Department for accelerate the mortality of forests and other vegetation by nearly Halifax, Canada (Runnalls, IISD, 2007) applied remote sensing climate change. Increasingly, the debate focuses on identifying Sustainable Development (OAS/DSD), the United Nations 600 percent compared to average background rates of change. and geographic information systems for elevation contours and credible options to mitigate greenhouse gas emissions, and Environment Programme (UNEP), the Global Environment Already, Amazon forest cover is drying out, and the 2005 drought hazard mapping to anticipate the impacts of sea level rise and advancing carbon sequestration projects to include considera- Facility (GEF) and the governments of Costa Rica and that affected parts of the Rio Negro in the Manaus region - the climate variability events. That single assessment took several tion of land-use change and avoided deforestation. At the Nicaragua, provides a useful example of ways to link climate worst drought on record in over a century - may presage more years, and its cost exceeded several hundred thousand dollars. same time, there is a growing urgency to anticipate and, where variability assessments with longer-term climate change assess- prolonged periods of drought.5 Based on current trends, the possible, adapt to the impacts of climate change. A critical ments and adaptation planning. Since the late 1990s, work in IPCC and other assessments warn that the larger Amazon forest LINKING ASSESSMENTS WITH challenge involves translating a growing scientific body of the wider San Juan basin - which comprises the largest freshwater ecosystem may “collapse” before the middle of the century. CLIMATE ADAPTATION detailed climate change assessments prepared at the global body in Central America - have identified the range of climate 2 Replicating the level of detail from the Halifax harbor or similar level into information that is useful at the local level. variability impacts. Specifically, work within the region has IMPROVING LOCAL ASSESSMENTS assessments is neither feasible nor necessary, since countries and focused on modeling extreme weather events such as hurricanes, These preliminary results of the La Plata and Amazon basin communities are already advancing from a foundation of work The findings of the Inter-Governmental Panel on Climate tropical storms and extreme seasonal drought. Vulnerability programs underscore the urgent need to sharpen climate already done. Experience in assessing climate variability and Change (IPCC) in 2007 establish the most authoritative assessments were done at a 1:10,000 scale which allowed assessments at the local level. However, several methodological planning for natural disasters and disaster risk mitigation are scientific assessment of climate change scenarios. The 2007 projected impacts to feed into identifying institutional and other challenges exist, which the newly-launched GEF proving directly relevant to the climate adaptation agenda. IPCC assessments conclude that climate change impacts are capacity-building needs in such areas as remote sensing and projects will help address. First, while work is advancing at highly localized. Determining a plausible range of impacts hazard mapping. Assessments also helped local planners in the national level in climate assessments, differences in model Several key lessons have emerged from existing projects. at the local level represents the first step towards preparing areas such as land-use planning and municipal zoning, to parameters often make it difficult to calibrate baselines and These include, among others: flood-plain mapping and building on-the-ground climate adaptation initiatives. dissuade families from building in especially vulnerable areas, data findings. Second, in order to be useful for local planners, floodways around densely populated areas; supporting integrated and to lend urgency to adopting building codes and standards climate change models must use scales of at least 1:10,000. watershed management, including protecting upper watersheds Remarkable advances are being made in bringing robust climate that withstand once-in-a-century Category Four winds. The Standard climate change models generate a range of scenarios, from deforestation; and supporting a range of critical infra- change assessments to a scale that is useful for local planners, central conclusion of the wider San Juan basin work is that including projected temperature increases comprising business- structure planning targets, including new locating sewage communities, the private sector, and others. At the same time, municipalities that undertake risk assessments, and prepare risk as-usual assumptions of projected greenhouse gas increases, treatment facilitates away from floodplains. local assessments remain expensive, technically complex and emission mitigation targets, and changing temperatures such present policy sequence challenges, since climate scenarios - as increases of 2 C, 4 C and 5 C. These broad scenarios are For more information on the work of the DSD, please see which are based on scenarios decades into the future -- extend FLOOD THREAT IN THE SAN JUAN transferred to the local level, using simple downscaling to include http://www.oas.org/dsd beyond the 3-4 year budget planning horizons of central RIVER BASIN (NICARAGUA) local weather variables by fixed monthly ratios (for precipitation) governments, municipal authorities and the private sector. and fixed monthly shifts (for temperature). However, to ensure robustness, scenarios need to be complemented with detailed In the face of these challenges, countries need not begin climate data sets generated from Electronic Distanciometers (EDM), adaptation work from scratch. Ongoing assessments of climate Total Stations or GPS triangulations. In addition, information variability - including the use of hazard mapping, establishing on soil and land-use, rates of land-use change and land early warning systems, increasing the resilience of vulnerable degradation6, are critical to generate maps at a scale of public buildings and critical infrastructure such as safeguarding 1:10,000 to 1:1000. These techniques are expensive, as municipal drinking water supplies from flooding and contami- well as labor and time-intensive. www.oas.org/dsd nation - provide practical lessons to countries preparing for longer-term climate adaptation work. Climate variability associated with the El Niño Southern Oscillation phenomena resembles the main impacts of projected longer-term climate 5. Field studies by Woods Hole Research Center suggest that Amazon forest ecosystems may not withstand more than two consecutive years of drought without starting to break down. Severe drought weakens forest trees and dries leaf litter leaving forests susceptible to land-clearing fires, which, in turn, produce smoke that hinders the formation of rain clouds. Logging change impacts. These include dry stationary cells, prolonged FIGURE ONE: GEF-UNEP-OAS Dialogue on Water and Climate and deforestation only worsen the effects, which can lead to a feedback cycle that further dries the forest. periods of severe drought, hurricanes, tropical disturbances, (2002), “Coping with Climate Variability in a Transboundary Basin 6. The transboundary diagnostic assessment prepared for first phase of the La Plata project identifies the strong correlation between land-use change and an increased flooding affecting cells with disproportionate humidity and heavy/tropical rainfall, areas previously immune from floods, particularly in urban area. For example,