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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 2
Evaluation of partial clinker replacement by sugar cane bagasse ash: CO
2
emission reductions
and potential for carbon credits
1. Introduction
Until the early 70’s, most development projects such as dams,
roads, buildings and industrial installations which require large
quantities of raw materials, such as steel, cement, among oth-
ers accounted only the economic benefit / cost rate. As a re-
sult of this development model it has emerged an increas-
ing environmental degradation caused by impacts from human
activities. The production of cement, for example, is an activity
that emits large amounts of gas which are capable of enhanc-
ing the greenhouse effect, as carbon dioxide (CO
2
). The result
of these various negative interferences aroused public opinion
and led several intearnational organizations to consider an es-
sential paradigm changing, where it should be pursued more en-
vironmentally friendly means of development. One can refer to
the reports generated by the Club of Rome regarding the various
forms of world development, conferences such as the Stockholm
Convention in 1972, the creation of UNEP (United Nations En-
vironment Programme) in 1980, the Brundtland Commission, in
1987, where one has coined the concept of sustainable develop-
ment. The summits of Rio 92 and its subsequent edition in 2002,
Rio +10, held in Johannesburg, South Africa, sought to formal-
ize the commitment of countries to put into practice sustainable
development.
1.1 Climate change
Some of the main themes discussed in Rio 92 and Rio +10 are the cli-
mate change and ways to prevent dangerous anthropogenic interfer-
ence with the climate system. The main scientific evidences of these
phenomena had already been addressed in reports drawn up by the
IPCC (Intergovernmental Panel on Climate Change), created in 1988.
Linked to UNEP and WMO (World Meteorological Organization),
the IPCC consists of a network of scientists from over 130 coun-
tries that aims to transform the scientific knowledge of the interna-
tional community on recommendations for government policies. In
its first report, the IPCC suggested the establishment of a political
negotiation instance, the UNFCCC (United Nations Framework
Convention on Climate Change), which was then created in 1990.
In its second report, in 1995, the IPCC has shown that there is an
intensification of global warming (Figure 1) due to excessive emis-
sion of greenhouse gases from human activities, such as methane
(CH
4
), nitrous oxide (N
2
O), fluorine gases (HFCs, PFCs, SF
6
) and
especially carbon dioxide (CO
2
).
Figure 1 – Global warming: naturally existing greenhouse gases trap the part of the solar radiation
that is reflected by the Earth in the form of heat. Released by man, additional greenhouse
gases amplify heat retained, intensifying the warming. (Adapted from UNFCCC)