In 2012, we engaged PricewaterhouseCoopers LLP (PwC) to provide limited assurance on our 2011 global Scope 1 and Scope 2 greenhouse gas data under the AICPA attestation standards. NVIDIA’s management assertion for US greenhouse gas data can be found below. PwC’s assurance report can be accessed here
NVIDIA Management Assertion
NVIDIA is responsible for the completeness, accuracy and validity of the Scope 1 (direct) and Scope 2 (indirect) greenhouse gas data contained in the Global Citizenship Report ("GCR") as of or for the periods indicated. The greenhouse gas data presented includes NVIDIA and its subsidiary operations. Data was collected for NVIDIA's global locations and activities including offices, laboratories, data centers, and sales offices.
With respect to the Scope 1 and Scope 2 greenhouse gas data identified within the NVIDIA GCR, management of NVIDIA asserts that the greenhouse gas data are presented in conformity with the assessment criteria set forth below.
NVIDIA's total global consolidated Scope 1 (direct) and Scope 2 (indirect) greenhouse gas (GHG) emissions ("Consolidated GHG Emissions"):
Year ended December 31, 2011 Scope 1 (direct): 2,167 metric tonnes of CO2 -equivalents (CO2-e)
Year ended December 31, 2011 Scope 2 (indirect): 43,893 metric tonnes of CO2 -equivalents (CO2-e)
Basis of presentation and assessment criteria
For the year ended December 31, 2011, NVIDIA's total consolidated Scope 1 (direct) and Scope 2 (indirect) GHG emissions associated with our global operations primarily include GHG emissions from purchased electricity (indirect) and natural gas combustion (direct). Other process-related emissions related to fugitive emissions from cooling devices have been excluded. NVIDIA is in the process of determining reliable monitoring procedures for this emissions source.
NVIDIA uses the US EPA Climate Leaders Protocol ("the Methodology") to calculate and report the Consolidated global GHG Emissions. The Methodology is supplemented by NVIDIA's own GHG emissions policies and procedures, where necessary. Application of the Methodology requires management to make certain judgments, estimates and assumptions. Critical methodology components include the following:
Base data utilized in the calculation of the Consolidated GHG Emissions is obtained from direct measurements, third-party invoices or estimates. NVIDIA estimates are used where direct or third-party measurement data is not readily available.
GHG emission factors
The metric tonnes of CO2-e associated with the activities noted above have been determined on the basis of measured or estimated electricity and fossil fuel use, multiplied by relevant carbon emission factors. Published emission factors were used to calculate emissions from operations.
Emission Source Type
Emission Factor Employed
Scope 1, US and
Natural gas and other fossil fuel use
GHG emissions from energy consumption are calculated using the US EPA Center for Corporate Climate Leadership's Emission Factors for Greenhouse Gas Inventories (2011).
Scope 2, US.
GHG emissions from electricity purchased in the US are calculated using US EPA eGRID 2012 v1.0 sub-regional emission factors.
Scope 2, Non-US.
GHG emissions from electricity purchased outside the US are calculated using the International Energy Agency's CO2 Emissions from Fuel Combustion (2009) for CO2, and the Energy Information Administration's Electricity Emission Factors (1999) for CH4 and N2O.
Emission factors for CH4 and N2O produced from electricity purchased in India from non-utility sources is estimated using the ratio of CH4 and N2O produced to CO2 produced in the combustion of diesel fuel. The ratio is calculated using diesel combustion factors derived from the EPA factors cited above for Scope 1.
Estimation methodology for electricity, natural gas and other fossil fuel use
If no primary energy use data is available, energy use is estimated based on an average energy use per square foot, using the US Department of Energy's Commercial Buildings Energy Consumption Survey (CBECS). CBECS provides an estimated average intensity based on the site's square footage, US climate zone and facility type. Climate zone equivalents for non-US sites are estimated by identifying similar climate zone ranges using data provided by NASA.
For other sites where data is partially available, energy use is estimated either based on a fixed monthly energy usage agreed to in our property leases, or based on an average of existing partial data.
If partial energy use or cost data is available, missing data is estimated based on the average of existing partial data. Approximately 10.1% of the Scope 1 and Scope 2 emissions are estimated for the year ended December 31, 2011.
In conformance with the Methodology, the Consolidated GHG Emissions represent 100% of the emissions from the facilities where NVIDIA has operational control globally.
GHG emissions calculation is subject to inherent uncertainty because of such things as emissions factors that are used in mathematical models to calculate emissions and the inability of those models, due to incomplete scientific knowledge and other factors, to precisely characterize under all circumstances the relationship between various inputs and the resultant emissions. Environmental and electricity use data used in GHG emissions calculations are subject to inherent limitations, given the nature and the methods used for determining such data. Finally, the selection of different but acceptable measurement techniques may result in materially different measurements.