Efecto de la presión de compactación

South Africa’s emissions stand at 1.49% of total global CO2 emissions as shown in Figure

4.2 below (Urban Earth, 2012). China is the greatest contributor to CO2 emissions, while the

US is in the second position. (This estimate was CO2 emissions from energy consumption

only and did not include other GHGs). The graph below contrasts South African CO2

Figure 4.2: South Africa CO2 Emissions compared to top global emitters (Urban Earth, 2012)

4.3.1 CCS in South Africa

CCS is a set of technologies that can greatly reduce CO2 emissions from new and existing

coal- and gas-fired power plants and large industrial sources (EPA, 2013). CCS is a three- step process that includes capturing the CO2 from power plants or industrial processes,

transporting the captured and compressed CO2 (usually in pipelines) and underground

injection and geologic sequestration (also referred to as its storage) into deep underground rock formations. These formations are often a mile or more beneath the surface and consist

of porous rock that holds the CO2. Overlying these formations are impermeable, non-porous

layers of rock that trap the CO2 and prevent it from migrating upward. After the capture, it is

compressed and then transported to a site where it is injected underground for permanent storage also known as sequestration. However, it is commonly transported by pipeline, but it can also be transported by train, truck, or ship. According to CCSA (2014), CCS uses established technologies to capture, transport and store carbon dioxide emissions from large point sources, such as power stations and it also have an important role to play to ensure manufacturing industries, such as steel and cement, can continue to operate, without the associated emissions. Hence, it is a key tool in tackling climate change, providing energy security, creating jobs and economic prosperity. Similarly, the principal rationale behind any effort to sequester carbon is to mitigate the progression and further impact of climate change. Given its high mitigation potential, the technology is often regarded as particularly relevant

which along China are seen as critical actors in any global mitigation scenario. India and Brazil are already the world’s fifth- and seventh-largest emitters in absolute terms; while South Africa has one of the highest emissions rates per capita (Rom’an, 2011). In the country’s national climate change response, the South African government gave a commitment to invest on clean coal technologies and efficient technologies where coal is still used, backed by stringent thermal efficiency and emissions standards for coal-fired power stations. As part of the commitment, South Africa then recognizes the need to move towards a low-carbon society by December 2009, committed at Copenhagen to reduce 34% of GHG emissions by 2020 and 42% by 2025 on condition that it received the necessary finance, technology and support from the international community. In view of this, the development of CCS has been declared a national research priority and the government was instrumental in setting up the South African Centre for Carbon Capture & Storage (SACCCS) in March 2009. According to SACCCS (2014) more than ninety percent of South Africa’s power is generated from coal and other industries e.g. the synfuel industry also uses large quantities of coal, which is resulting in the release of over 400 million tonnes of CO2 annually. Therefore, the

government then committed SACCCS to reduce CO2 emissions and to investigate the

feasibility of CCS in South Africa or alternatively, improving energy efficiency and switching to non-fossil fuel based power generation as an essential if necessary in addressing the problem. However the existing energy infrastructure has a life expectancy of about fifty years and the impact of replacing this infrastructure prematurely would be damaging to the economy. The capture of CO2 at the point of release and the deep underground storage

(CCS) thereof will help to decrease CO2 emissions. CCS technology is a way of bridging the

gap from today until the existing energy infrastructure is replaced with non-fossil fuel based power generation. Therefore, IEA (2014) asserts that coal-fired power plants and heavy industries such as cement and iron/steel are responsible for the majority of GHG and particulate emissions worldwide. Combining these processes with CCS can significantly reduce GHG emissions. Despite the advantages, successful implementation of CCS is dependent on geographical, environmental, legal and cost considerations. Successful deployment of CCS is critically dependent on comprehensive policy support. A policy approach focusing on funding, costs and risks, subsidies/penalties, and technology support will move CCS from the pilot stage to widespread deployment. However, Norway - Mission to the UN (2009) believes that if the world is to achieve necessary climate goals, it is essential that developing countries make use of climate-friendly technology. Coal-fired power plants may account for nearly half of the world’s power production in 20 years from now. CCS technology can help to reduce emissions from these plants by as much as 85-95 percent. To make these possible, developing countries need to develop the necessary policies and legislation. According to Kharecha and Hansen (2013), human caused climate change and air pollution remain a major global scale problems and these are mostly attributed to fossil

fuel burning. Mitigation efforts for these problems should be undertaken concurrently in order to maximize effectiveness. Such efforts can be accomplished largely with currently available low-carbon and carbon-free alternative energy sources like nuclear power and renewable, as well as energy efficiency improvements. Likewise, without nuclear power, it will be even harder to mitigate human-caused climate change and air pollution. This is fundamentally because historical energy production data reveal that if nuclear power never existed, the energy would have almost certainly been supplied by fossil fuels which cause much higher air pollution related mortality and GHG emissions per unit. According to Kharecha and

Hansen (2013) using historical production data, we calculate that global nuclear power has

prevented an average of 1.84 million air pollution related deaths and 64 gigatonnes of CO2- equivalent (GtCO2-eq) GHG emissions that would have resulted from fossil fuel burning. On the basis of global projection data that take into account the effects of the Fukushima accident, we find that nuclear power could additionally prevent an average of 420 000 − 7.04 million deaths and 80 −240 GtCO2-eq emissions due to fossil fuels by midcentury, depending on which fuel it replaces. By contrast, we assess that large scale expansion of unconstrained natural gas use would not mitigate the climate problem and would cause far more deaths than expansion of nuclear power. Also, Markandya and Wilkinson (2007) noted that nuclear power has one of the lowest levels of GHG emissions per unit power production and one of the smallest levels of direct health effects, yet there are understandable fears about nuclear accidents, weapons uses of fissionable material and storage of waste. Nonetheless, it would add a substantial further barrier to the achievement of urgent reductions in GHG if the current 17 percent of world electricity generation from nuclear power were allowed to decline.