CO₂ is acknowledged as a major contributor to climate change. In Ireland, ordinary Portland cement manufacture is the second largest industrial source of CO₂ and NO_X emissions, after the generation of electricity from fossil fuels. In addition, about one fifth of all dioxin emissions from industry in Ireland arise from cement production. However the production of GGBS from blastfurnace slag, an industrial by-product, generates very low CO₂ emissions, and zero emissions of other pollutants. The table below shows figures for CEM I cement and Ecocem GGBS per tonne of production:

Type of Emissions	Portland Cement	Ecocem GGBS
CO2	930 kg	0*
NOX	3.5 kg	< 0.071 kg**
SO2	2.0 kg	< 0.00013 kg**
CO	2.0 kg	< 0.00690 kg**
PM10	0.4 kg	< 0.0105 kg

*Ecocem’s GGBS has a carbon footprint of zero. Carbon credits from EmissionZero are used to offset the very small (less than 30kg/tonne) CO₂ emissions from the electricity, gas and diesel used in the grinding process. This certificate shows the carbon footprint of Ecocem GGBS prior to the use of carbon credits to offset the remaining CO₂ emissions.

**Emissions from gas used to dry material prior to grinding. Almost 80% of electricity used in the process is green, thereby contributing very little to emissions.

In Ireland, cement manufacture is the second largest industrial source of CO₂ and NO_X emissions, after the generation of electricity from fossil fuels. In addition, about one-fifth of all dioxin emissions from industry in Ireland arise from cement production. However the production of GGBS from blastfurnace slag, an industrial by-product, generates very low CO₂ emissions, and zero emissions of other pollutants.

SO₂ and NO_X lead to acidification of soils and surface waters and can cause nitrogen saturation in terrestrial ecosystems. Increased ground-level ozone formation is caused by NO_X and CO. All of these pollutants can have direct effects on human health.

Embodied CO₂ is the quantity of CO₂ emitted in the manufacture, supply and construction of a building or structure.

In Ireland, embodied CO₂ accounts for between 10–15% of our national emissions, which means that it accounts for between approximately 7,000,000 and 10,000,000 tonnes of CO₂. This significant figure is equivalent to the CO₂ emissions of 2,500,000 cars or C1 rated houses.

There are a number of reasons why more attention should be paid to embodied CO₂:

• Embodied CO₂ savings can be made on a cost neutral basis by specifying/using Ecocem on your construction projects.
• Embodied CO₂ savings are more significant than operational CO₂ savings because all the savings are made at the start of a structures life—it will be many years (up to 30 years) to make equivalent operational savings. The UN has stated that it is over the next 10 years we need to make significant savings or it may be too late.
• Whereas buildings can be retrofitted to improve the operational CO₂ savings, embodied CO₂ savings can only be made during construction—therefore it is very important to maximise the savings day one. Using Ecocem means you are using the most sustainable building material in the world.

A lot of focus to date has been to reduce the operational CO₂ of buildings or structures. This is being managed by increasing insulation, air-tightness, installing solar panels and/or biomass burners etc, and installing better glazing among other items. All of this can come at a significant cost which might get you from a C1 to an A2 rating and a corresponding saving of 3 tonnes of CO₂ per annum.

Those who wish to design sustainable developments must consider both the embodied CO₂ and the operational CO₂. Failure to do this will result in millions of tonnes of lost savings and further damage to our ever increasingly fragile planet.

Once a structure is built, the opportunity is lost to make embodied CO₂ savings: so whether you are the developer, architect, engineer, planner, contractor or other member of the project team, don’t wait for someone else to act. We all have a responsibility to leave the planet a better place then when we arrived.

Click here to find out how significant embodied CO₂ is in the Irish housing industry.

About 90% of the environmental impact of concrete provided at the construction site derives from cement. Using GGBS as a partial replacement for Portland cement yields significant improvements in the environmental performance of concrete. The reductions achieved in various pollutant effects by using 50% GGBS per tonne of concrete are illustrated in the table opposite:

Indicator	Reduction achieved using 50% GGBS
Global Heating Gas Emission	40%
Acidification	34%
Winter Smog	34%
Eutrophication	32%
Primary Energy Requirements	29%

Ireland is committed to reductions in emissions by 2010–2012 as follows:

• EU Directive 88/609/EEC obliges Ireland by 2010 to make reductions in emissions of SO₂ by 50% and of NO_X by 75%.
• The Kyoto Treaty imposes on Ireland a substantial reduction of CO₂ emissions by 2012 (limited to 13% above 1990 levels). In 2000 Ireland was 24% above the 1990 emission level. We are expected to be over 37% above the 1990 level by 2012 in the absence of corrective measures.

If Ireland fails to meet these targets, costly financial penalties will be incurred. However the use of GGBS will make an important contribution to achieving Ireland’s European and international obligations to reduce pollution. And it will do so without imposing any additional cost once the Irish Government recognises this reality.