In a time perspective, the rate and degree of carbonation is important as regards carbon dioxide capture. It is related to concrete quality, type of binder, local environment and microclimate. The data on outdoor concrete is good. This investigation has sampled and analyzed concrete from indoor environments and crushed concrete as road base etc. The data shows that there are many different kinds of environments and within those there are different types of hindrances that slow down carbonation. To understand this, one must look at the mechanism of carbonation and the effect of the local microclimate. This is the case with dry indoor concrete that has remaining uncarbonated cement grains and cores of portlandite in seemingly carbonated concrete.