As happens when there are multiple stresses, different stresses may be prevalent in different situations. Warming of the atmosphere also may result in some benefits, such as the enhancement of high-latitude agriculture and reductions in the effects of wintertime diseases. Politicians and decisionmakers need to be aware of the vulnerability and adaptability of ecosystems and activities in their countries and their region, as well as elsewhere around the world, to design and implement sustainable development initiatives that take advantage of beneficial climate changes and to build strategies for international commercial exchanges in light of differential climate change impacts around the world. In some cases, however, appropriate downscaling and other techniques are available, making possible the use of GCM outputs, and regional models suitable for impact and vulnerability analysis are now being developed for this region. The largest impacts of climate change are likely to affect natural ecosystems and sectors related to primary production, such as agriculture, livestock raising, and fisheries.
Water resources are at risk in many areas.
Human health and human settlements, especially in coastal lowlands and environmentally and socioeconomically marginal areas, also are vulnerable. Impacts are expected to be less severe for industry, transportation, and infrastructure outside of flood-prone areas, although increased frequency or severity of extreme events may affect these sectors. Austral forests are located on the southernmost tip of the subcontinent and on Tierra del Fuego Island. Grasslands, shrublands, and deserts the most extensive ecosystems in the region are found on the Mexican Pacific and Venezuelan Caribbean coasts, in northeastern Brazil, and in inland areas between Brazil and Bolivia. The Gran Chaco ecosystem is located across parts of Bolivia, Paraguay, and Argentina.