CarbonMetrics

The Secretariat of UNFCCC published a carbon footprint of its activities in 2006, covering 2004 and 2005. That footprint contained multiple material errors and has been removed from the UNFCCC website.

The greenhouse gas emissions of UNFCCC were about 25,000 tCO2 per year. In the 2008 carbon footprint this has apparently been reduced to 1,687.2 tCO2.

How did they do it? I mean, even if you offset the emissions they still occurred. Did they ground all staff? Do they have their own fleet of biofuel-powered airplanes?

Note also the precision - in 0.1 tCO2. Emission factors of IPCC have only 3 significant digits, and therefore the calculated CO2 emissions cannot have more than 3 significant digits either.

CDP proposes that reporting companies report their greenhouse gas emissions on the basis of financial accounting rules. At the moment companies can choose between consolidation approaches [financial control, operational control, equity share] when applying ISO 14064-1 or the GHG Protocol. The consequence of this is that carbon footprints of companies are often not comparable.

The proposal of CDP is that companies report 100% of the emissions over the companies under financial control. This includes leased assets. Joint ventures and participations report greenhouse gas emissions according to the percentage interest or equity share.

The Carbon Disclosure Project requests information on greenhouse gas emissions and climate change strategies to 4700 of the planet's largest companies every year.
It does so on behalf of 534 institutional investors with a combined $64 trillion in assets under management.