AWS's new carbon footprint tool criticised

AWS, by some margin the world's largest public cloud computing provider, has released a new carbon footprint tool that lets users view the carbon emissions they have generated through their AWS use by broad geographical location and by AWS services, including EC2 (compute) and S3 (storage). The tool's carbon footprint estimates for AWS include Scope 1 (emissions from direct operations) and Scope 2 (emissions from electricity production) data. The company said that the data reported was in line with Greenhouse Gas Protocol and ISO14064.

Both public and private sector customers had lamented the absence of such a tool and gone through some contortions to try and estimate their AWS carbon footprint. The new tool only shows emissions data by extremely high-level geographical groupings such as EMEA (Europe, Middle-East and Africa) and AMER (North, Central and South America) not by AWS Regions themselves; a lack of precision that may frustrate some users hoping to optimise emissions reductions by swapping workloads to the AWS region with lowest emissions.

See: Data centre sustainability: “Through a glass, darkly”?

The new AWS carbon footprint tool is available through the billing console.

The company said its estimates factor the grid mix of the AWS Regions where workloads run, following GHGP guidance -- and its carbon emission estimates (which it has not published a detailed breakdown of, to some frustration in the carbon accounting community) also factor in the AWS power usage effectiveness (PUE) in its data centers. AWS flags improvements versus on-premises workloads in the tool, saying it does this using data from S&P Global's 451 Research which "found that AWS can lower a workload's carbon footprint by 88% for the median surveyed US enterprise data centers, and compared to European data enterprise centers, up to 96% once AWS is powered with 100% renewable energy. This target is on path to meet by the year 2025..."

New AWS carbon accounting tool draws faint praise

Adam Turner, Head of Sustainable Digital and ICT for the UK Government and Public Sector at the Department for Environment, Food and Rural told The Stack: "It's an improvement. We first asked in 2018. So in four years we have now have a tool that government and public sector customers can easily access to understand their carbon footprint in AWS as AWS want to present it. We asked AWS to share the working, calculations, and models behind their figures and they stated they would share as much as they could. We also stated that the element on the dashboard that describes typical saving from moving from to the cloud was very 'salesy' and not based on facts i.e it was worst-case public sector data center, moving to best-case AWS. We really appreciate the work AWS have done on the architecting in the cloud tool set which is vendor agnostic (as far as we can tell but as yet untried)."

"The methodology used by AWS to allocate the emissions isn't detailed... Both Azure and GCP detail their methodology a lot more."Private sector AWS CUSTOMER

The unit of measurement for carbon emissions is metric tons of carbon dioxide-equivalent (MTCO2e), an industry-standard measure. This measurement considers multiple greenhouse gases, including carbon dioxide, methane, and nitrous oxide. All greenhouse gas emissions are converted to the amount of carbon dioxide that would result in equivalent warming. Carbon emissions data is available from January 2020 onwards. New data on carbon emissions from cloud use is available monthly, with a delay of three months as AWS gathers and processes the data. All values in the customer carbon footprint tool are rounded to the nearest one-tenth ton.

One major private sector user told The Stack, preferring not to be named: "This first version is quite limited, it only shows Scope 1 and 2 and Scope 2 [and] is reported as market-based so it will show 0 for all regions covered by renewable energy purchase (physically this doesn't change how carbonised your workload is since it's using the grid). This market-based approach is a kind of carbon accounting trick allowed by the GHGP methodology."

They added: "The methodology used by AWS to allocate the emissions to its customers isn't detailed as well. Most importantly, embodied emissions and other upstream emissions (their own scope 3) are not included. GCP does better on Scope 2, with location-based reporting and Azure includes Scope 3 (I haven't been able to test it because I don't use their services). Both GCP and Azure also detail their methodology a lot more.

"To summarise, in my view, today the AWS report is only a partial carbon reporting tool; it cannot be really used by a tech team to improve their usage (it's not granular, and not transparent)."

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