PROBLEM TO BE SOLVED: To provide a carbon dioxide generation system that creates an environment suitable for the photosynthesis of crops in a greenhouse for protected horticulture.SOLUTION: A carbon dioxide generation system 1 installed in a greenhouse for protected horticulture has a carbon dioxide generating device 10 that generates carbon dioxide A11, and humidification means (humidification device 20) that humidifies and cools the carbon dioxide A11 and A12 generated by the carbon dioxide generating device 10.【課題】炭酸ガス発生システムにおいて、施設園芸用温室における作物の光合成に適した環境を作る。【解決手段】施設園芸用温室に配置される炭酸ガス発生システム１において、炭酸ガスＡ１１を発生させる炭酸ガス発生装置１０と、この炭酸ガス発生装置１０が発生させた炭酸ガスＡ１１，Ａ１２を加湿及び冷却する加湿手段（加湿装置２０）と、を備える。【選択図】図１
