Impacts, Adaptation, and Vulnerability to Climate Change:

2007 IPCC Working Group II Report

Working Group II of the Fourth IPCC (Intergovernmental Panel on Climate Change) Assessment Report states that climate change in the next few decades is inevitable. Even the strongest possible mitigation actions taken now could not prevent a temperature increase of at least 0.6 degreee Centigrade during that time frame. This makes adaptation measures essential. Mitigation efforts must also begin now, or climate change will eventually exceed our capacity to adapt in the long term.

The IPCC’s Report, released in November, contains three “working groups.” Working Group II focused on “Impacts, Adaptation, and Vulnerability” of natural and human systems to climate change.

Changes in Natural Systems Already Underway

Working Group II’s report states that several natural systems have already been altered. Plants and animals  have begun changing their locations and habits due to warming. Satellite observations have shown earlier greening of vegetation in the spring, many plant and animal species are moving poleward, and birds and fish are migrating earlier. The IPCC Working Group has high confidence that the changes being observed in ocean and freshwater biological systems are due to the warming of water temperatures. The ocean is also becoming more acidic because of higher carbon uptake, but the effects on marine ecosystems have not been determined, according to the report.

The impacts of rising temperatures, changes in precipitation, and rising sea levels on natural and human systems will vary in magnitude, timing, and region, states Group II, partly depending on each area’s ability to adapt.

Effects of Climate Change

Ecosystems around the world will have a hard time adapting to the combination of climate change and other disturbances during this century, according to the report. Floods, drought, wildfire, an increase in the number of insect outbreaks, land-use change and over-exploitation of resources are contributing factors affecting adaptation ability.

Net carbon uptake by land-based ecosystems is likely to peak by mid-century, then the rate of uptake is likely to start declining, the report states. If the temperature increase is limited to 1-3 degrees C over the next century, then crop production in countries closer to the poles is projected to increase slightly. If the rate of warming is greater than that, crop production in those regions could decrease. At lower latitudes, even small increases in temperatures will reduce crop productivity, the report adds.

The effect of climate change on water supplies will vary. More than one sixth of the world’s population relies on meltwater from glaciers and snow in the mountains. Those water supplies are predicted to decline in the course of the 21st century. Areas that are prone to drought in mid latitudes will likely increase in extent.

Not surprisingly, coastal areas are at special risk, primarily due to the rise in sea levels. As sea levels rise, coastal and mega-delta communities will experience more floods; millions of people could be affected as early as the 2080s, according to the report. Asian and Australian coasts are at an even higher risk because of increasing development in these areas. With sea level rise, small islands will eventually become inundated. If the Greenland ice sheet and the West Antarctic ice sheet were to melt completely, the sea level would rise up to 7 meters and 5 meters, respectively, states the Group II report. But this is estimated to occur over centuries or millennia.

While things heat up, health concerns arise. The report states that climate change may affect millions of people through malnutrition, diarrhea, and cardio-respiratory disease. More deaths and injury will occur as a result of heat waves, floods, and drought. And again, areas that struggle to adapt will suffer the most.

On a positive note, there will be fewer deaths due to cold temperatures, less energy needed for heating, and less snow on the road, making travel easier.

Regional Differences

The future costs and benefits of climate change will vary for different parts of the world, but overall, the bigger the change in climate, the more negative the effects will be. Poor, developing regions will be hit the hardest because of their dependence on climate-sensitive resources and low adaptive capacity. Studies project that Africa is one of the most vulnerable continents, , and the adaptations that are taking place now may not be enough for future changes.

In Polar Regions, the thickness and extent of glaciers and ice sheets are projected to be reduced. Traditional ways of life such as hunting and travel over ice and the nature of physical structures are being threatened. Glacial lakes are increasing in number and size, the ground is becoming unstable in permafrost and rock avalanche areas, and some ecosystems are changing. Communities will need to adapt or relocate.

Nearly all European regions are anticipated to be negatively affected by some future impacts of climate change, states the report. More frequent flash floods and coastal floods may occur, winter tourism will be affected by glacier retreat and reduced snow cover, and up to 60 percent of Europe’s species in some areas will be lost by 2080 if high greenhouse gas emissions continue.

Significant biodiversity loss is a large risk in tropical Latin America; predicted decreases in water supply would cause tropical forests to be replaced with savanna in eastern Amazonia.

The report shows high confidence that water resources in North America will be strained. In certain areas of North America, crops that depend on heavy water applications may suffer. But in the early years of this century, yields of rainfed crops may experience higher yields in some regions of North America because of the longer growing season, states the report.

Need for Adaptation Measures

Some of amount of additional warming in the future is unavoidable due to past emissions; therefore, adaptation measures will be necessary regardless of any actions taken now to reduce greenhouse gas emissions. Communities are trying to adapt at present, but more effort will be needed. Adaptation methods can be technological, behavioral, managerial, or policy-related, states Group II. Limits and costs are not yet known, and adaptation will need to be supported by mitigation, which is discussed in Working Group III’s report.

Source: http://www.ipcc.ch/ipccreports/ar4-wg2.htm

-- Katie Starzec, CASMGS Communications

kstarzec@ksu.edu

-- Steve Watson, CASMGS Communications

swatson@ksu.edu