Climate Change

Abstract

Climate change is defined as the warming of the climate system due to human activities. Emission of greenhouse gases (GHGs), which cause an increase in radiative forcing, is the main contributor, and the only climate forcing agent currently considered in life cycle impact assessment (LCIA) methodologies. The direct consequence is an increase in the temperature of atmosphere and oceans, which leads to several types of higher-level impacts such as sea level rise, extreme meteorological events and perturbations in rainfalls, which in turn cause damages to human health and ecosystem quality. All the LCIA methodologies use GWPs (Global Warming Potentials), developed by the Intergovernmental Panel on Climate Change (IPCC), as midpoint characterisation factors since they are based on state-of-the art and peer-reviewed publications and have a relatively low associated uncertainty. Some LCIA methodologies also propose endpoint characterisation factors. However, these factors are considered highly uncertain because of the complexity of the impact pathway so that further research is still needed to improve robustness of the models. Recent new developments are addressing the accounting of biogenic CO2 emissions, the timing of GHG emissions, and the development of characterisation factors for terrestrial albedo changes induced by human activities.