Author

LARSSON, Nils

International Initiative for a Sustainable Built Environment, larsson@iisbe.org

Abstract

1 INTRODUCTION

A considerable number of papers produced by IPCC and others have outlined the science behind climate change predictions, probable impacts, mitigation measures and possible adaptation. In this short paper, we attempt to identify some of the key links between climate change and the building sector and then to suggest some possible responses for rapid reduction of greenhouse gases under emergency conditions.

2 GREENHOUSE GASES IN CLIMATE CHANGE

The anthropogenic driver of climate change is the increasing concentration of greenhouse gases (GHG) in the atmosphere, chiefly CO2, but also including Methane, Sox and Nox gases. The World Resources Institute (WRI) estimates that buildings are directly responsible for 15.3 percent of global GHG emissions. To this should be added a share of industrial emissions (for materials) and for road transport. A very conservative estimate of building-related GHG share would therefore be in the range of 20 percent to 25 percent, and this would be higher in developed countries. It is therefore clear that a strategy for the diminution of GHGs will have to include the building sector as main target for GHG reductions.

Trends in emissions and global temperature increases

The International Energy Agency1 has concluded that … although opinion is mixed on what might be considered a sustainable, long-term level of annual CO2 emissions for the energy sector, a consensus on the need to limit the global temperature rise to 2 ºC is emerging. To limit to 50% the probability of a global temperature increase in excess of 2 ºC, the concentration of greenhouse gases in the atmosphere would need to be stabilized to a level around 450 ppm CO2-eq. Is such a target likely to be achieved? Although the IEA is guardedly optimistic, trends inemissions seem to point in a different direction. In its 2008 Climate Science Issue Brief2, the World Resources Institute cites recent research in the field: Raupach et al. note that the growth rate of carbon dioxide emissions from fossil fuel consumption and industrial processes has grown from 1.1% per year over the 1990s to more than 3% per year from 2000 to 2004 … The authors find that declining trends in energy intensity of GDP and carbon intensity of energy are now being slowed and even reversed, and thus decarbonization trends are not as strong as previously.The WRI editors comment that… Scenarios of future climate-related damages (such as those of the IPCC), which to date have been based on more optimistic assumptions, may prove to be conservative descriptions of possible future damages.

Key words
Climate change, Greenhouse gases, Built environment