Urban CO2 Budget: Spatial and Seasonal Variability of CO2 Emissions in Krakow, Poland

Krakow, with an area of 327 km2 and over 750,000 inhabitants, is one of the largest cities in Poland. Within the administrative city borders several anthropogenic CO2 source types are located, including car traffic, household coal and natural gas burning, and industrial emissions. Additionally, the biosphere produces its own, seasonally variable, input to the local atmospheric carbon budget. In order to quantify each of CO2 budget contributions to the local atmosphere, a number of analytical and numerical techniques have been implemented. The seasonal variability of CO2 emission from soils around the city has been directly measured using the chamber method; CO2 net flux from an area containing several source types has been measured with a relaxed eddy accumulation—a variation of the eddy covariance method. Global emissions inventory, as well as local statistical data have been utilized to assess anthropogenic component of the budget. As other cities where CO2 budget was quantified, Krakow proved to be a net source of this greenhouse gas, and the calculated annual mean net flux of CO2 to the atmosphere equal 6.1 kg C m−2 is consistent with previous estimations.