Abby L. Harvey
GHG Monitor
12/4/2015
Carbon capture and storage is likely to play a role in future efforts to decarbonize the global economy, but the technology presents many challenges beyond its hefty price tag, according to a new report released this week by the United Nations Environment Programme. “There is … a clear trade-off between climate change and other environmental impacts of coal and gas power. Technologies which reduce carbon emissions from coal and gas power plants appear to increase other environmental impacts,” according to the report, which also addresses various renewable forms of energy, such as wind, solar, and hydropower.
The report says while CCS will be important in carbon mitigation efforts, with the potential to reduce the greenhouse gas emissions of modern power plants with CCS between 22-26 per cent compared to existing coal power plants, the plants with CCS produce larger quantities of other pollutants. “[I]n terms of particulate matter and photochemical smog emissions, which constitute the most important threats to human health, the analysis for modern plants with CCS show lower emissions than current typical coal power plants, but higher emissions than modern plants without CCS,” the report says.
The increased health impacts of CCS plants can be traced back to the CO2 capture process, which, due to its energy intensiveness, leads to increased air pollution. Modern CCS plants also demonstrate higher freshwater ecotoxicity and eutrophication compared to current plants without CCS, according to the report.
That is not to disregard the necessity of the technology in efforts to reduce carbon emissions and limit global warming to 2 degrees Celsius, the report says. “CCS technologies are required in most 2°C scenarios and could reduce GHG emissions significantly, but increase other pollution problems by 20-80 per cent.”
The U.N. agency added that the “development of CCS technologies is currently not on track.” Only one full scale CCS coal plant is currently in operation and those currently underway have on the whole experienced setbacks throughout their development. “The technology’s greatest challenge lies in overcoming the combination of high investment costs and high operational costs.”
