Continuous measurements of CO2
fluxes were conducted using the micrometeorological method at three locations in Sakai, Osaka, Japan, evaluating CO2
fluxes from five landscapes: a dense urban center, a moderately urban area, a suburb, an urban park, and a rural area. Irrespective of the land cover type, all urban landscapes acted as net annual CO2
sources, with emissions ranging from 0.5 to 4.9 kg C m−2
. The magnitude of the annual CO2
emissions was negatively correlated with green fraction.