Especially Affected Systems Sectors and Regions

Water Freedom System

Survive Global Water Shortages

Get Instant Access

For the first time the systems, sectors, and regions most likely to suffer adverse effects were identified in the latest IPCC report, providing important details ofrisks, impacts, and vulnerabilities at different levels offuture warming. The especially affected ecosystems identified were tundra, boreal forest and mountain regions, Mediterranean types, tropical rainforests where precipitation declines, coral reefs, mangroves and salt marshes, and systems dependent on sea ice. A sector identified as of special concern is the health of vulnerable populations who have a low capacity to adapt. As Hurricane Katrina and the European heat wave of 2003 showed, even in high-income countries the poor, the elderly, and young children can be particularly at risk from climatic extremes.10

For sea ice, the IPCC projected a decrease in both the Arctic and Antarctic under every unmitigated emissions scenario, with summer sea ice in the Arctic disappearing almost entirely toward the end of this century. This would have far-reaching adverse consequences for ice-dependent species and ecosystems as well as speeding up the warming far into the interior ofthe bordering continental regions of Russia, Canada, and Alaska.11

Large losses of sea ice threaten the continued existence ofpolar bears. Based on the projections available for the latest assessment,

A Safe Landing for the Climate the IPCC predicted that this risk would occur for a global warming of 2.5-3.0 degrees Celsius above the preindustrial level. But it seems clear that this threshold could be much lower, as the observed rapid loss of summer ice (about 9.1 percent a year for the 1979-2006 period) exceeds the projections in nearly all the latest IPCC models.12

In already dry regions in the mid-latitudes, in drier parts of the tropics (predominantly developing countries), and in regions that depend on melting snow and ice for river and stream flows, water resources will be adversely affected. Glaciers in regions such as central Asia and the Himalaya and Tibetan plateau are melting faster than expected. Large adverse effects on water supply availability are predicted, threatening billions of people with water insecurity. Developing countries are not the only ones at risk. Serious water supply impacts have been seen in Australia from the 2001-07 drought—the most extreme and hottest drought recorded for this continent. Water inflows into Australia's largest and most important river basin, the Murray-Darling, are expected to decline 15 percent for each 1 degree Celsius of warming, and dramatic and adverse impacts are forecast for the water supply for large cities in southeast Australia.13

Agriculture and food supply in low-latitude regions, which are predominantly poor developing countries, are projected to be adversely affected even at low levels of warming. Recent climate trends, some of which can be attributed to human activities, appear to have had a measurable negative impact on global production of several major crops. In India, for example, it is clear that agricultural production has suffered due to a combination of climate change and air pollution.14

Substantial to sometimes severe adverse effects on food production, water supply, and ecosystems are projected for sub-Saharan

Africa and small island developing states if the average temperature reaches 1.5 degrees Celsius above preindustrial level. Large river deltas, such as those of the Nile in Africa and of the Mekong and Ganges-Brahmaputra in Asia, are particularly at risk as they are home to large vulnerable populations and have a high exposure to sea level rise, storm surges, and river flooding.15

Was this article helpful?

0 0

Post a comment