EarthTalk: Questions and Answers About Our Environment

Dear EarthTalk: Are carbon capture technologies pie in the sky or really feasible as a global warming mitigation technique?                   ~ Paul C., Scranton, PA

The short answer is … we’ll see. To understand how to remove carbon dioxide (CO2) from our atmosphere, it is important to first look at how it gets there and why it’s a problem in the first place.

Human activities are the dominant contributor to CO2 emissions through fossil fuel burning, electricity consumption and transportation. According to NASA, humans have caused increased CO2 concentrations by half since the 18th century, resulting in a 1.8°F temperature increase. This may seem insignificant, but the consequences are becoming more and more apparent, so scientists are going all out to figure out ways to limit potentially irreversible effects moving forward. Various emission reduction strategies are being put in play to help stave off the worst effects of global warming.

Carbon capture & storage was once viewed as a game changer in efforts to stave off climate change, but is it too little too late now? Credit: Alberta Newsroom, Quest Carbon Capture (CCS) Canada, FlickrCC.

One of the most promising is so-called “carbon capture and storage” (CCS). Technologies that prevent carbon from entering the atmosphere by storing it have been around since the mid-1970s, but only recently have they scaled up to meet the demands of larger industrial settings. There are three steps to CCS: capturing, transporting and storing. First, CO2 is separated from other gasses that are released during industrial processes. Next, the CO2 is transferred through pipelines where it is then stored and often repurposed. Currently, there are 80 facilities in the process of implementing CCS, and 16 that have already done so. Its removal efficiency is targeted at 90 percent, with some able to reach 95-99 percent.

CCS is definitely a feasible method for removing CO2 from the atmosphere. Most carbon emissions come directly from a facility; the biggest advantage of CCS is its ability to prevent CO2 from escaping right from the source. The International Energy Agency estimates that CCS is capable of removing up to 20 percent of CO2 from industrial facilities. Also, other greenhouse gasses like nitric oxide and sulfur dioxide can also be sequestered. The CO2 that is captured can also be utilized for the creation of other commercial products like concrete and polymers. Geologically stored CO2 can be repurposed to collect geothermal heat, meaning geothermal energy can be extracted sustainably.

While this does sound like a perfect solution to our problems, there are some potential pitfalls. Although CCS does have high efficiency, the 90 percent of CO2 being removed isn’t enough, considering where we are with emissions now. With the race to develop maximum removal CCS projects, the costs increase greatly as well. According to the Global CCS Institute, the 26 plants created as of 2021 have only removed 0.1 percent of emissions, meaning that for this technology to be suitable, it would have to be applied in every industrial facility, globally—right now. So we have a situation where the costs outweigh the benefits, and due to its unpromising results“ …there’s no way it can actually improve to be better than replacing coal or gas with wind or solar directly,” says Stanford’s Mark Jacobson. “The latter will always be better, no matter what, in terms of the social cost.”

Most environmental advocates agree that focusing on renewables is the best course of action to reduce our greenhouse gas emissions. But CCS nevertheless remains a viable weapon in the arsenal of climate change fighters. With the various technologies advancing, it will play an especially important role as a bridge to a sustainable future for the planet.

CONTACTS: Global CCS Institute,; Mark Z. Jacobson,

Dear EarthTalk: I know that upgrading the energy efficiency of my home will make it less expensive to heat or cool, but will it also raise its market value significantly?      ~ J.B.M., St. Louis, MO

That depends on your definition of “significant!” According to a study published in the Journal of Urban Economics, with every 10 per cent increase in energy efficiency, a home’s market value increases by approximately 2.2 per cent. In another set of studies, the government-backed energy efficiency experts at Energy Star found that their certified homes in Maryland sold between 2012 to 2015 had a two to five per cent sales price increase, simply because they were deemed energy efficient.

This pattern has been observed across the U.S. A six percent increase was seen in the final price tags of Energy Star certified homes in Austin-Round Rock, Texas (sold 2009 to 2016), and an eight percent increase was found in select housing markets across Oregon, Idaho and Washington (2015).

Why is this happening? To put it simply, the average home buyer has become savvier in the world of sustainability. In a report by the National Association of Realtors (NAR), it was found that 51 percent of agents interacted with clients that were very interested, or at least somewhat interested, in sustainability. In a related report by Energy Star, the stats showed that 83 percent of home buyers desired more efficient windows, 81 percent wanted more efficient appliances, and 80 percent wanted more efficient lighting.

Undoubtedly, homeowners have come to understand that energy-efficient upgrades translate into lower energy costs. According to the U.S. Department of Energy, the average family spends approximately $2,200 annually on energy bills. Thirty percent of that cost can be removed just like that through energy-efficient home modifications.

That being said, the increase in demand for sustainable homes and home upgrades may also be driven by a sense of personal responsibility. A sweeping study by Simon-Kucher & Partners covering 17 countries and 10,000 participants revealed that a significant paradigm shift in purchasing habits was occurring. Eighty-five percent of respondents reported that they had changed their spending habits over the past five years to accommodate a greener lifestyle. In addition, one-third of the population is willing to spend more for sustainable products or services—as much as 25 percent!

If you’re feeling the same inclination, there are many ways to upgrade your home’s energy efficiency. Insulating walls is usually where people begin, but sealing air leaks (even the small ones!) with caulking, spray foam and weather stripping can save anywhere from five to 30 percent on energy. Ducts specifically are known to have leaks that can cause losses of as much as 60 percent of the heated air traveling through them. Energy efficient light fixtures, windows, doors, skylights, appliances and hot-water heaters are all available for purchase these days, and when used in congruence with a programmable thermostats and smart-device timers, you can save a surprising amount of money in energy savings by the end of the year.

CONTACTS: Simon-Kutcher study,;  NAR Report, Energy Star,;

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