The need for geosequestration

Even with the strongest imaginable efforts to convert to alternative sources of energy, fossil fuels will continue to be the primary source of energy globally for decades to come.

The International Energy Agency projects that global energy demand will increase by more than 50 per cent between now and 2030 – an average annual rate of increase of 1.8 per cent. More than 70 per cent of the increase in demand is forecast to come from developing countries, with China alone accounting for almost one-third of the increase.

World primary energy demand in the reference scenario. From International Energy Agency – World Energy Outlook 2007.

The Agency projects that 84 per cent of the increased demand will be met from fossil fuels, fuels which when combusted for energy emit the greenhouse gas carbon dioxide. The largest increase in demand will be for coal, primarily to generate electricity in China and India. This is despite projected rapid increases in use of renewable energies, including wind, solar, and geothermal.

The Energy Agency projects a 57 per cent increase in carbon dioxide emissions from energy between 2005 and 2030. Even if governments around the world successfully introduced all the policies and measures they are currently considering to reduce emissions, carbon dioxide emissions would still grow by 27 per cent by 2030, according to the International Energy Agency projections. But the Agency warns that it would take considerable political will to push these policies through, with many bound to meet resistance from industry and consumers.

Scenario analysis by the Intergovernmental Panel on Climate Change indicates that carbon dioxide emissions would have to peak before 2015 and then, by 2050, be reduced to 50 per cent to 80 per cent below year 2000 levels if the increase in global average temperatures from climate change is to be limited to 2 to 2.4°C.

Geosequestration – capturing carbon dioxide that would otherwise be emitted to the atmosphere and injecting it to be stored in deep geological formations – is the only technology available to make deep cuts in greenhouse gas emissions while still using fossil fuels and much of today’s energy infrastructure. The International Energy Agency describes it as “one of the most promising options for mitigating emissions in the longer term”. In its Special Report on Carbon Dioxide Capture and Storage, the Intergovernmental Panel on Climate Change said that geosequestration “has the potential to reduce overall (greenhouse gas) mitigation costs and increase flexibility in achieving greenhouse gas emission reductions. In its Climate Change 2007: Mitigation of Climate Change, the IPCC concluded that geosequestration was among the technologies with the largest economic potential to reduce emissions from electricity generation, as well as in the cement, ammonia, and iron manufacturing industries. It also found that attempts to stabilise greenhouse gas concentrations in the atmosphere at lower levels increased the emphasis on technologies such as geosequestration.

Geosequestration is not a replacement for taking actions which increase energy efficiency or maximise the use of renewable or other less-carbon-intensive forms of energy. A portfolio approach, taking every opportunity to reduce emissions, will be required to meet the challenge of minimising global climate change. Global modelling by CO2CRC indicates that widespread deployment of carbon dioxide capture and storage would result in atmospheric concentrations of carbon dioxide being at least 100 parts per million lower than would otherwise be the case.