Carmen Bunzl - Universidad Pontificia Comillas

Chapter 1. Introduction 11
The IPCC (2007) forecasts accelerated warming under a variety of scenarios.
Even if atmospheric concentrations of greenhouse gases could be held constant
at the year 2000 levels through the twenty-first century, the global climate
would warm 0.6ºC (+/- 0.3ªC). Under a variety of long-term scenarios,
temperature increases could range from 1.1 to 6.4ºC by 2100.
The changing climate will result in numerous impacts. The sea level will rise,
on average globally, about 20 to 60 centimetres through 2100. Extreme weather
events may increase: hot extremes, heat waves, heavy precipitation, tropical
cyclone intensity. Agricultural, fishery, and forest productivity will change,
with adverse impacts more likely with higher levels of warming. Some aspects
of human health will be affected, such as heat-related mortality or changes in
infectious disease vectors like malaria. Some species of plants and animals,
especially those inhabiting unique ecosystems, may be at risk as the climate
changes, especially since the rate of change may exceed their capacity to
migrate or adapt.
Some impacts of anthropogenic warming could include potential
catastrophic events. Partial loss of ice sheets on polar land could result in rapid
and large increases of sea level rise – on the order of ten or more meters – and
imply major changes in coastlines and inundation of low-lying areas. A warmer
climate may induce strong, positive feedbacks, such as through the release of
large amounts of methane from melting of permafrost.
The capacity to adapt to such impacts varies substantially around the world,
as evident by different human capital and technology as well as effective
government institutions. Developing countries, where greater poverty and
vulnerability limit the capacity to act, would be the most serious harmed.
4 Climate change policy architecture
The impacts of global climate change pose serious, long-term risks. Global
climate change is the ultimate global-commons problem; damages are
Escuela Técnica Superior de Ingeniería ICAI Carmen Bunzl Boulet Junio 2008