This study examined the relationship among carbon dioxide emissions and linkage effects using Input–Output (IO) data of the information and communications technology (ICT) industry between South Korea and the USA. As we wanted to find out if the ICT industry, which the world is passionate about, is a sustainable industry. The linkage effects are analyzed to determine the impact of ICT industry on the national economy, and CO₂ emissions of the industry are analyzed to determine how much influence it has on air pollution. In addition, we classify ICT industry by ICT service and manufacturing industries as the key industries in Korea and the US. Data were collected from OECD ranging from 2006 to 2015 in order to quantitatively estimate backward linkage, forward linkage effect, and carbon dioxide emissions. The results indicated that ICT manufacturing industry in Korea has high backward and forward linkage effects. CO₂ emissions from ICT service is more than from ICT manufacturing in both Korea and the US. We wanted to find out if the ICT industry, which the world is passionate about, is a sustainable industry. As a contribution, ICT manufacturing and service industries in Korea and the United States are directly compared, and CO₂ emissions over 10 years are analyzed in a time series.