This report is the first part of Beyond Zero Emissions’ Zero Carbon Industry Plan. It focuses on cement production, which is the single biggest industrial producer of emissions. Cement production causes 8% of global emissions – more than the global car fleet. The report outlines how Australia can move to a zero carbon cement industry in 10 years.
Cement is the key ingredient of concrete, the material we make more of than anything else. Around the world in 2015, we made 4 billion tonnes of cement. Concrete is everywhere – so commonplace as to be all but invisible – and is used to make large buildings, bridges, dams, tunnels and stadiums. Despite its mundane reputation, concrete has been a vital part of celebrated structures for millennia, from the Egyptian pyramids and the Roman Colosseum to the Panama Canal and the Sydney Opera House, and people will continue to use cement in huge quantities in the decades ahead. But to enable rapid action on climate change, we must quickly change the way we make it.
Since the 19th century, the industry standard cement type has been Portland cement, for which the raw material is limestone. The first stage of cement making is to transform limestone (calcium carbonate - CaCO3 ) into lime (CaO), thus releasing carbon dioxide (CO2 ) as a waste product. This single process accounts for about half of the carbon emissions associated with cement making, and therefore around 4% of the world’s total emissions. The rest comes from the heat required to drive the production processes and the energy to grind and transport material. When cement emissions are mentioned at all in public debate, it is typically to note that little can be done about them. However, this is true only if we continue to assume cement is limestone derived Portland cement. In fact, there are existing alternatives with far lower carbon emissions, at similar cost, and with no loss of performance. We can't continue to use limestone to make cement any more than we can keep burning coal.
This report describes a pathway for tackling cement emissions, involving five strategies. Strategies 1 to 3 deliver a zero carbon Australian cement industry in just 10 years by changing the way cement is made. Strategies 4 and 5 would enable us in the longer term, to go beyond zero emissions, by changing the way we build and turning our built environment into a carbon sink.
Governments and industry can support a rapid shift to a zero carbon cement industry. One powerful stimulus to all the technologies presented in this report would be a national policy which puts a price on cement carbon emissions, including imported cement. The Australian Government could back up such a policy with a national target to reduce the carbon intensity of cement, which becomes progressively more stringent. This target could be supported by public investment into research and deployment of low-carbon cements, similar to the support for renewable energy provided by the Clean Energy Finance Corporation and the Australian Renewable Energy Agency. We suggest that the Australian cement industry should be lobbying for policies of this type with the aim of becoming world leaders in this field. Governments and the construction sector could provide a huge boost by prioritising the procurement of low carbon cement, and mandating their use for non-structural purposes. Such changes to procurement would be facilitated by increasing the incentives to use low-carbon cements in sustainability rating tools such as Green Star and IS (Infrastructure Sustainability) Rating Scheme. Finally governments should introduce new regulations or incentives to encourage the use in cement production of stockpiled fly ash and other waste materials such as waste glass, red mud and bagasse ash.