Civil Engineering Reference
In-Depth Information
Introduction
Fernando Pacheco Torgal
Abstract This chapter starts with an overview on CO
2
emissions and climate
change addressing key investigations and important related events. The situation
of the European Union concerning energy efficiency is described. A short analysis
of the nearly zero-energy building (NZEB) concept is presented. A topic outline is
also presented.
1CO
2
Emissions and Climate Change
Four decades ago several investigators used a computer model based on the fixed-
stock paradigm to study the interactions between population, food production,
industrial production, pollution and the consumption of non-renewable resources.
As a result, they predicted that during the twenty-first century the Earth's capacity
would be exhausted resulting in the collapse of human civilization as we know it
(Meadows et al.
1972
).
Two decades after that an update of this study was published showing that some
limits had already been crossed (Meadows et al.
1992
).
Climate change is one of the most important environmental problems faced by
the Planet Earth (IPCC
2007
; Schellnhuber
2008
).
This is due to the increase of carbon dioxide (CO
2eq
) in the atmosphere for
which the built environment is a significant contributor. In the early eighteenth
century, the concentration level of atmospheric CO
2eq
was 280 parts per million
(ppm); at present, it is already 450 ppm (Fig.
1
).
Keeping the current level of emissions (which is unlikely given the high economic
growth of less developed countries with consequent increases in emission rates)
