In the Province of Siena, GHG emissions are, at the moment, totally compensated by the CO2 uptake by local ecosystems, determining the condition of Carbon Neutrality as result of the REGES (Riduzione delle Emissioni di Gas a Effetto Serra) Project and of the provincial Energy Plan (2012).
This achievement is ascertained by the annual GHG inventory, performed by Ecodynamics Group (University of Siena) in compliance with the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines which include Energy, Industry, Waste, Agricultural, Forestry and Other Land Use (AFOLU) sectors. The inventory is implemented following a geographical criterion (except for electricity consumption when imported) and based on a bottom-up approach (data directly collected in the Siena area).


In 2006, for which the first GHG inventory was certified, the percentage abatement of gross emissions was 72%. This constitute the baseline of the monitoring. In 2011 the Province of Siena achieved the Carbon Neutrality with a percentage abatement of 102%, and a decreasing trend in subsequent years. In 2016 the GHG balance (Gross emissions – Forest uptake = Net emissions) shows 108% of the abatement.

The Province of Siena had total emissions of over 1,226,000 tons CO2-eq in 2016. These were made up of:


Fossil fuels
Waste and water


The Province of Siena is the first case in Europe, in which the ISO 14064-1 standard of certification is applied to a large governmental/territorial system. Methods, data and results of the GHG inventories have been revised and validated by the certification agency RINA Services S.p.A.
The applied standard methods allow minimizing uncertainty and producing accurate, coherent and reproducible results.
As requested by the ISO 14064-1 certification a sensitivity analysis is regularly performed on the GHG inventory.

The overall uncertainty of the balance results is around 10%.


1. The provincial area has a low population and industrial density, as well as extensive forested area (around 45% of the total surface is represented by forests) and is characterized by an agriculture-based economy. Also the exploitation of geothermal resource is a peculiarity of the area, contributing to the production of electricity from alternative source that is higher than the provincial energy demand.

2. At this stage, no standardized method for accounting CO2 emission due to the exploitation of geothermal fluid has been established at the international level. The 2006 IPCC Guidelines do not provide a methodology to estimate emission due to geothermal use. This emission can be seen as a part of the cycles that includes volcanoes and similar phenomena, that can happen in a random and sudden way or in a more continuous trend; anyhow they are part of the natural processes: CO2 emissions from geothermal power plants are balanced by a reduction in natural release of CO2 from geothermal fields. Following this line of thought, the European Community does not include Greenhouse gas emissions produced from geothermal power plants in the burden shares allocated to countries. Consequently, in Italy and the rest of Europe, GHG inventories do not take into account CO2 emissions from geothermal power plants. Therefore, that emission is omitted from GHG inventories of the Province of Siena. The fact remains that there cannot be a worse time in human history to release further CO2 into the atmosphere…

3. The forest uptake, accounted for the Province of Siena, follows a prudential approach. Esteems are lower by 14% (on average) compared to the forest uptake calculated by the CNR-Ibimet, and published on the Report on the State of the Environment of the Province of Siena (2010).