Which statement best describes carbon capture and storage (CCS) and its primary challenges?

• A. CCS captures CO2 from emission sources and stores it underground, offering potential emissions reductions; challenges include cost, energy penalty, leakage risk, and long-term storage.
• B. CCS uses solar energy to power carbon removal from the atmosphere and has no cost or leakage concerns.
• C. CCS generates CO2 to be released into the atmosphere to balance emissions.
• D. CCS is a form of renewable energy with no environmental risk.

Answer: (A)

Carbon capture and storage is about preventing CO2 from entering the atmosphere by capturing it at the emission source and storing it deep underground. This can meaningfully reduce emissions from activities like fossil-fuel power generation or cement production, where large steady outputs of CO2 occur. The most accurate description emphasizes that it captures CO2 from sources and stores it underground, offering potential emissions reductions, while facing several real hurdles: the high upfront and operating costs of capture equipment, an energy penalty because running the capture and compression systems consumes energy and reduces overall plant efficiency, the risk that CO2 could leak from storage sites or along pipelines or wellbores, and the need for long-term monitoring, liability, and regulatory frameworks to ensure the CO2 stays put for centuries.

Other statements don’t fit because CCS isn’t powered by solar energy with zero cost or leakage concerns, it doesn’t create CO2 to release into the atmosphere, and it isn’t a renewable energy source with no environmental risk.