This week, the World Economic Forum (WEF) highlighted the EPFL 'Low Carbon Cement - Harmonizing environmental goals and housing needs' report, which focusses on how low-carbon cement can help to address global housing needs while at the same time meet climate targets.
It is expected that that 600m housing units, or nearly 40m annually, will need to be built between 2015-30 to ensure affordable housing for all by 2030, as listed in the UN's Sustainable Development Goals (SDG 11.1). The task ahead is particularly challenging in the Global South, where 80 per cent of this new housing is required and resources are limited. In addition, cement producers will need to meet this challenge while supporting the <1.5°C climate target of the Paris Agreement. To achieve these dual goals of housing targets and the drive for net-zero by 2050, low-carbon cements, including LC3, play a key role.
Urban growth and housing demand
In addition to global population growth particularly centred on the Global South and rising per capita GDP, the growing need for housing is also the result of increasing urbanisation. The projected annual growth rate of the urban population between 2021-50 is 0.32 per cent in Europe, two per cent in Asia and 3.6 per cent in Africa, according to the UN Department of Economic and Social Affairs. In Africa urbanisation is expected to occur at 10 times faster than it did in Europe, over the next 30 years. The evidence is that governments struggle to keep pace with increases in housing demand and this leads to the emergence of slums, currently the home of more than 1bn people, according to UN Habitat. In 2018 Asia was home to two out of three slum dwellers, followed by sub-Sahara at 23 per cent, Latin America at 11 per cent and the Global North at four per cent.
The demographic need for housing is defined by the EPFL report as the difference between the housing stock in 2015 and 2030, or the need for housing due to population growth and changes in household structure. The demographic need is largest in Asia at 168.8m units, followed by Africa with 74m units and Latin America with 26.7m units. Housing stock renewal is estimated at approximately 1.48bn housing units by 2030, or an increase of 309.2m units between 2015-30.
Cement consumption
Long-term cement demand is complex, develops at different rates in different regions and therefore, difficult to predict. In the Global North, approximately every citizen has consumed some 16t of cement per capita in the 30 years between 1961-90 and again from 1991-2020. Meanwhile, every African has consumed 700kg and 2.5t in the same respective periods, while China consumed over 20t per capita in the past 30 years.
Cement production
While the cumulative global cement production was around 75bnt in the last 30 years (1991-2020), cement production is expected to grow to 127bnt over the next 30 years (2021-50), or a 70 per cent increase, according to EPFL. Such an increase could result in CO2 emissions of around 95bnt, or 24 per cent of the remaining global carbon budget, which the IPCC has estimated at around 400bnt in 2021. Approximately 90 per cent of this demand would be generated in the Global South to build houses and infrastructure.
In terms of building housing in the Global South, taking into account the relatively moderate requirement to build basic housing units, the report states that only three per cent of global cement production would be required.
In addition, there has been a shift in terms of the location of cement capacity with the Global South taking centre-stage. In 1960 approximately 12 per cent of all cement was made in the Global South, now it has a 94 per cent share of production. China is expected to reduce its cement production from 2.5bnt to slightly more than 1bnt, while Africa and the rest of Asia will more than compensate for this reduction by increasing their production from 1.3bnt to around 3bnt, according to the report.
Therefore, new decarbonisation technologies such as carbon capture, utilisation and storage (CCUS) will be needed to be installed in the Global South's cement plants. However, currently pilot plants are mainly located in the Global North. The high cost of CCUS may well be unfeasible in Africa, claims EPFL, given the high cost of producing cement on the continent.
LC3 Low-carbon cement solution is a good fit for Africa
As a result, the need to transition to low-carbon cement is a necessity. LC3 or limestone calcined clay cement is seen as the ideal solution by EPFL for the Global South to meet cement production needs, while reducing clinker by 50 per cent and lowering CO2 emissions. As clay reserves are widely available in Africa, where limestone is scarce, cement production can be moved closer to the centres of consumption. Capital investments for LC3 production are also much lower than for clinker plants and the need for cement imports could be reduced.
"If cement production in Africa will grow from 200Mt in 2020 to 900Mt in 2050, it would require additional capital investments of some US$21bn, but for Portland cement plants the necessary investments would be at least five times higher," reports teh EPFL.
Download the full 'Low Carbon Cement - Harmonizing environmental goals and housing needs' report.