The balance

The balance

In the Province of Siena, greenhouse gas emissions are now completely compensated by forest uptake of CO2, determining a condition of carbon neutrality. This goal is demonstrated by the annual greenhouse gas inventory, drawn up by the Ecodynamics Group (University of Siena), according to 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines, that include the energy, industrial, waste, agriculture, forest and other soil uses sectors.

The inventory was implemented on a geographic basis (except for imported electricity) and used a bottom-up approach, gathering data directly in the Siena area without using regional or national averages.

In 2006, the year of the first greenhouse gas inventory and the year of reference for monitoring, the gross emission reduction was 72%.

In 2011, the province reached carbon neutrality with a reduction of 102%, that continued to decrease in subsequent years. In 2016, the greenhouse gas balance (gross emissions – forest uptake = net emissions) showed a reduction of 108%.

The Province of Siena emitted more than 1,226,000 tons of CO2-eq in 2016:

  • 74% from fossil fuels
  • 15% from livestock (enteric fermentation and manure management) and agriculture (nitrogen and urea fertilizers, forest fires and forest felling)
  • 9% from waste and water treatment
  • 2% from industry.

In 2016, CO2 uptake by the forests of the province (> -1,324,000 tons CO2) removed all the greenhouse gases emitted by local human activity.



The Province of Siena is the first case in Europe of application of the ISO 14064-1 certification standard to a large administrative/regional system. The methods, data and results of the greenhouse gas inventories were verified and validated by the certification agency RINA Services S.p.A. The application of standard methods make it possible to reduce uncertainty to a minimum and to produce accurate, coherent, reproducible results. As required by ISO 14064-1 certification, the sensitivity of the greenhouse gas inventories was determined: the overall uncertainty of the balance was about 10%.