This is the first case applying 2-haloethylamine to CO2 capture. The prospect of global warming and the urgent need to reduce atmospheric concentration of carbon dioxide has prompted actions at many levels. The conventional capture of carbon dioxide is predominantly based on chemical absorption using ethanolamine. Recent developments of carbon dioxide capture focus on new materials, such as ionic liquids, zeolites, membranes, carbonaceous absorbents, and metal–organic frameworks. However, no unique solution exists currently to solve the problem of carbon dioxide capture. In order to examine the efficiency of 2-chloroethylamine as an absorbent of CO2, we treated an aqueous solution of 2-chloroethylamine hydrochloride with CO2 in the presence of an alkali, e.g., NaOH, under ambient conditions. The absorption was complete within 30 min, seemingly following first-order reaction kinetics. Furthermore, we succeeded in capturing CO2 from ambient air using 2-chloroethanolamine. The efficiency of 2-chloroethylamine as an absorbent of CO2 could be attributed to the production of stable 2-oxazolidinone, therefore, this reaction is favored thermodynamically. Compared with previously reported absorbents, this novel system is capable of capturing CO2 with an extremely high efficiency of 1 mol per mol absorbent under ambient conditions, even from the atmosphere. This potential method could be used to capture CO2 particularly from small, mobile, or low-concentration emission sources.