In the United States most of our electricity from the grid comes from power plants that run off of natural gas or coal. The power plants generate 35 percent of all carbon dioxide emissions in the United States. Emission free technologies such as wind, solar and nuclear won’t be able to address the problem of global emissions fast enough to start reducing it by 4 percent a year. Climate scientists predict that global emissions should be reduced to zero before the end of the century.
Some may say this is hard to believe.
The United States has seen an increase to the production of low – cost natural gas. Many electrical utilities are adopting natural gases as a cleaner alternative to coal. Natural gas is primarily methane. When methane is burned, it releases about half as much carbon dioxide as a coal. One disadvantage of natural gases is the leakage of incombustible methane. The incombustible methane is much more potent than carbon dioxide.
Aside from switching from coal to natural gases, studies show that capturing carbon dioxide and storing it underground is another way to reduce emissions from fossil fuels. The stored carbon dioxide could possibly be used for making renewable plastic. Capturing the carbon dioxide and storing it underground is said to be one of the most viable options for lessening the effects of global warming. More research has to be done to see how the stored gas interacts with the structures around it.
A professor of energy resources engineering, Hamdi Tchelepi, is using supercomputers to study interactions between injecting CO2 gas and the complex rock fluid system in the ground.
Some may question what will happen if the carbon dioxide leaks from the ground. Researchers have developed a model called “Storage Security Calculator”. This is a study of what would happen if 12 billion tons of CO2 were injected underground and were left there for 10,000 years.
The results of the study show that minimal leakage would occur providing a suitable storage space is chosen. There are two main ways that leakage can occur. Leakage can happen from injection wells and abandoned wells that were once used for oil and gas production. There are three ways that CO2 can be trapped underground. Residual trapping can permanently trap it; this is when CO2 gets trapped in small gaps between the rocks underground. Solubility trapping occurs when CO2 dissolves into water. The final way is mineral trapping. This is the conversion of CO2 into a solid mineral. These methods can take hundreds of years to trap CO2 because they care controlled by natural physical processes.
Researches have created a future forecast by looking into how much leakage can occur in three specific scenarios. The scenarios include: where CO2 is stored in an offshore site, a “well- regulated” onshore site and a “poorly – regulated” onshore site. All three scenarios assume that CO2 storage begins in 2020 and ends by 2050. Although the model runs 10,000 years into the future this timeline is used in the research study. The provided charts show the expected leakage from each baseline scenario in model simulations.
The black lines on the chart represent the total CO2 injected. The grey lines represent when the injection ceases, and the red lines show the proportion of CO2 that is leaked. The blue lines show the proportion of CO2 that is permanently trapped and the green dashed lines show the total proportion that is retained underground.
The conclusion came out to be that the poorly regulated scenario represents the “highly unlikely” event of CO2 being stored in regions with poorly regulated oil and gar industries. The findings of the study show that CO2 storage is safe. The technology is available, the process is known and safety is assured, therefore it should be a go ahead. Some researches are less confident because of additional studies that show that CO2 storage over 100,000 years found the technology could lead to delayed warming of the atmosphere as well as oxygen depletion and elevated CO2 concentrations in the ocean.
The new study shows that 1% of leakage or less per thousand years from an underground stored reservoir would be required to maintain conditions close to those of a low-emission projection. Professor Martin Blunt, chair in petroleum engineering at Imperial College London, says “CO2 storage is not like nuclear waste, which will corrode and eventually leak out of anything it’s stored in. Unlike nuclear waste, CO2 becomes safer and more secure the longer it stays in the ground due to a range of physical processes, such as mineralization.”
The International Energy Agency, IEA, reported that global CO2 emissions from energy-related activities have not risen since 2013. Even as the global economy grew, CO2 emissions stayed at 32.1 billion tons. The two largest emission countries are China and the United States. They both registered declines in emissions of about 1.5 percent.
There has been a dramatic growth of renewable energy; this has been the biggest cause of decoupling. Last year alone, more than twice as much money was put into new capacity for renewables such as wind and solar power than into new power stations for burning fossil fuels, according to an analysis by Frankfurt School of Finance and Management.
Renewable energy still only delivers about 10 percent of the total electricity generated worldwide. Ulf Moslener, a coauthor of Frankfurt, stated that recent investment in green energy has cut annual CO2 emissions from all energy sources. The growth of renewables is causing a sharp decline in coal burning in both China and the U.S. It is noted that a quarter of European Union countries no longer burn any coal for power generation.