University of Pardubice Jan Perner Transport Faculty Transport and ...
University of Pardubice Jan Perner Transport Faculty Transport and ...
University of Pardubice Jan Perner Transport Faculty Transport and ...
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socioeconomic issues. In fact, social <strong>and</strong> cultural concerns may far outweigh all other factors as<br />
industry <strong>and</strong> government make critical decisions regarding environmental issues. 52<br />
3.3.1 Climate change<br />
Due to uncertainties about future emissions <strong>and</strong> concentrations <strong>of</strong> greenhouse gases, their net<br />
warming effect in the atmosphere, <strong>and</strong> the response <strong>of</strong> the climate system, estimates <strong>of</strong> future<br />
temperature change are uncertain. A greenhouse gas (GHG) is a gas in an atmosphere that<br />
absorbs <strong>and</strong> emits radiation within the thermal infrared range. This process is the fundamental<br />
cause <strong>of</strong> the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water<br />
vapour, carbon dioxide, methane, nitrous oxide, <strong>and</strong> ozone.<br />
With these caveats in mind, the IPCC made the following projections <strong>of</strong> future warming (IPCC,<br />
2007): The average surface temperature <strong>of</strong> the Earth is likely to increase by 1.1 to 6.4°C by the<br />
end <strong>of</strong> the 21st century, relative to 1980-1990, with a best estimate <strong>of</strong> 1.8 to 4.0°C. The average<br />
rate <strong>of</strong> warming over each inhabited continent is very likely to be at least twice as large as that<br />
experienced during the 20th century.<br />
Warming will not be evenly distributed around the globe. L<strong>and</strong> areas will warm more than oceans<br />
in part due to water's ability to store heat. High latitudes will warm more than low latitudes in<br />
part due to positive feedback effects from melting ice. Most <strong>of</strong> North America; all <strong>of</strong> Africa,<br />
Europe, northern <strong>and</strong> central Asia; <strong>and</strong> most <strong>of</strong> Central <strong>and</strong> South America are likely to warm<br />
more than the global average. Projections suggest that the warming will be close to the global<br />
average in south Asia, Australia <strong>and</strong> New Zeal<strong>and</strong>, <strong>and</strong> southern South America. The warming<br />
will differ by season, with winters warming more than summers in most areas. 53<br />
52 UNEP: Environmental problems [online]. 2010 [cit.2012.04.19]. Found from:<br />
http://www.unep.org/climatechange/<br />
53 Climate change [online]. 2012.04 [cit.2012.04.14]. Found from: http://epa.gov/climatechange/<br />
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