Energy and climate change

Energía y cambio climático

Introduction

Human intervention in the carbon cycle has become a relevant concern in recent times. Global warming is a phenomenon due to the atmospheric concentration of greenhouse gases (GHGs): carbon dioxide, methane, nitrous oxide and chlorofluorcarbons, believed to be irreversible. CO2 is the most important GHG, its contribution to the radiative forcing of climate is estimated in about 70%. Changes in the global concentration of these gases depend on: the level of emissions as a by product of economic activities, the natural assimilative capacity of the global ecosystem, and the abatement activities. Notwithstanding the existing uncertainties about the evolution of global warming and its real consequences for human societies and the integrity of ecosystems, the identification of policies and measures to control adverse effects of climate change represents an important issue in national and international agendas. The global nature of this phenomenon points also to the need for an internationally co-ordinated effort to prevent and control the concentration of anthropogenic GHG in the atmosphere. Recently, on the basis of imperfect information but discernible evidence of human influence on climate change, a ‘precautionary approach’ has been adopted by the United Nations Framework Convention on Climate Change (UN FCCC), since the Rio Earth Summit in June 1992. The Kyoto Protocol to the UN FCCC agreed after a series of preparatory meetings, on December 1997, strengthened the Rio commitments by defining legally binding emission targets for industrialised countries and creating mechanisms to enrol developing countries in the GHG reduction effort.