CCS stands for carbon dioxide capture and storage. Humankind has extracted the fossil fuels that lay deep in the earth’s crust for tens of millions of years and used them to build a world replete with comforts and conveniences. Using fossil fuels means burning them, which generates carbon dioxide. As a result, CO2 has increased in the atmosphere, contributing to global warming. CCS seeks to capture the CO2 generated by factories and power plants, transport it to sites suitable for geological sequestration, and store it underground. With its potential to lower CO2 emissions quickly and dramatically, CCS holds great promise as a key weapon in the battle against global warming.
Global Warming—Humankind's Most Serious Challenge
By now most of us have experienced global warming firsthand. In February 2009, summer-like temperatures were recorded in locales around Japan, and the following April Hiroshima and Oita were hit by midsummer heat. Globally, the effects of climate change have been observed in such phenomena as the warming and shrinking of Alaska's permafrost and rising sea levels. Each day brings further corroboration of the predictions laid out in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), issued in 2007—a report written by more than 800 contributing and 450 lead authors on the basis of 29,000 data sets from 75 studies, reviewed by more than 2,500 scientific experts, and approved unanimously by the representatives of 130 governments. According to AR4, greenhouse gas emissions increased by 70% between 1970 and 2004, and emissions of CO2, the most abundant greenhouse gas, increased by 80%. The report predicts that by the year 2100, average global temperatures will have risen between 1.8ºC and 4ºC. And scientists believe that the warming trend is accelerating.
Although this may seem a trivial increase, the effect, depending on the locale, is expected to include searing temperatures, devastating heat waves, torrential rains, storm surges, bigger hurricanes and typhoons, and droughts. These changes will destroy ecosystems, lead to poor harvests and famine, and increase the danger from such health threats as heat stroke and the spread of infectious disease. As a result, poverty and hardship will spread, catalyzing new conflicts around the world.
(1) CCS as a key weapon in the fight against global warming
It is important to understand that we have fallen so far behind in the battle against climate change and that we are fast reaching the point where it will no longer be possible to halt global warming or restore the earth to its original state; all we will be able to do is mitigate the warming trend and adapt to the impact. This is why prompt and sweeping action is needed. The single most important measure we can take to achieve prompt and sweeping reductions in CO2 emissions and stem global warming is CCS—and capturing the CO2 from power plants and factories before it is released into the atmosphere and storing it underground. This is why CCS has been given a prominent place in the IPCC's scenarios and response options. But if CCS is to have a real impact on global warming, it must be introduced around the globe. This will require speedy implementation of demonstration projects and accelerated deployment.
In terms of technology, CCS is broadly divided into three stages—capture, transport, and injection and storage. Each of these phases can be accomplished with existing technology, but further technical advances are needed to meet the challenges of large-scale application, improved efficiency—particularly in terms of energy use—and total system optimization.
To the top on the page.An illustrative example of ｔhe global potential contribution of CCS
According to the Research Institute of Innovative Technology for the Earth (RITE), Japan's combined onshore and offshore (sub-seabed) storage capacity is 150 billion tons, the majority of it offshore. Offshore storage offers the more practical option for Japan, taking into account issues of landowner rights and environmental regulation. In 2006, an amendment to the 1996 Protocol to the London Convention opened the way for sub-seabed storage of CO2 under international law. In Japan, an amended Marine Pollution Prevention Law came into force in 2007, but there are continuing concerns regarding the law's applicability in practice.
(2) The Role of CCS in Japanese Policy
In March 2008, the Japanese government released its “Cool Earth—Innovative Energy Technology Program.” The plan called for an international goal of halving global greenhouse gas emissions by 2050, embraced the national target of a 60%–80% reduction, and emphasized the need for development of CCS technology to achieve such goals. In the joint declaration adopted by the G8 Hokkaido Toyako Summit the following July, the Group of Eight Leaders stated, "We strongly support the launching of 20 large-scale CCS demonstration projects globally by 2010." Immediately following the summit, the Japanese cabinet adopted an Action Plan for Achieving a Low-carbon Society, which called for a large-scale CCS demonstration project beginning in fiscal 2009, establishment of a platform technology for geological CO2 storage by 2015, and full-fledged CCS deployment in private industry from 2020. To achieve the last goal, the plan set targets for reducing the capture cost from 4,200 yen/ton to less than 3,000 yen/ton by 2015 and less than 2,000 yen/ton by 2020. Japan's CCS program picked up further momentum the following December, when the Council for Science and Technology Policy gave the green light for a 100,000 ton/year CCS demonstration project.
To the top on the page.