Sunnier Skies Ahead? Cloud Giants Dial Down The 'Greenwash'

Computing's 2024 cloud sustainability research reveals positive changes in some of the environmental data provided by big three cloud vendors

Sunnier Skies Ahead? Cloud Giants Dial Down The 'Greenwash'

Hyperscale cloud service providers market their services on the basis that not only are they more cost-effective than the on-premise datacenters of old, but that this efficiency makes them greener by default.

To some extent this is true, but datacenters are sucking up ever greater quantities of electricity and water to power and cool these gigantic buildings – and that's after the carbon expended used to build them in the first place.

If you're one of the 84% who told our Tech Trends survey that sustainability matters to them and their businesses, how do you decide which cloud offers the best combination of cost efficiency and sustainability?

An obvious first step is ESG reports, but these often run to 100 pages. Unvarnished data has to be hunted down (usually in an appendix), and getting details involve navigating multiple footnotes and references to supporting documentation. It's not surprising that fewer than 10% of those in our survey said they read ESG reports in detail.

When we asked what CIOs wanted from vendors to help them make informed cloud decisions, we found that almost everyone wanted the same thing – good quality data that was easy to compare from one vendor to another. They wanted transparency, clarity, and metrics they could understand.

To this end, Computing compiled the first Sustainability Matrix in 2022, consisting of four separate quadrants. Each quadrant is made of up to eight criteria we score the cloud giants against.

The quadrants are:

The results have been reported as a series of vendor head-to-head comparisons, like this one from last year. This article is our first report from our 2024 findings, with more to come.

Every year we apply the knowledge we've gained from interviewing those in the datacenter industry, or experts in certain aspects of cloud sustainability and the tech community, to update the matrix with new or amended criteria, and remove metrics that no longer offer a meaningful comparison. You can find detail of this years' matrix here. There are 50 points available in total.

And the winner is..

For two years running, Microsoft Azure was judged the most sustainable cloud, but its margin of victory over second-place Google Cloud Platform (GCP) narrowed last year. This year, Google Cloud Platform is the winner, beating Azure into second place. AWS retains third place in our sustainability rankings.

The visualization below shows the maximum score available in each category, and the score each vendor obtained this year underneath it. The final set of bars sets out the overall scores.

In our third year of research, some of earlier Computing's calls - such as those for cloud services data to be disaggregated from the rest of the businesses, better data on waste and circular economy, and greater transparency more generally - have been partially heeded. This applies to all three companies to varying degrees, but to Google in particular.

Google has made considerable progress in data quality and transparency. It breaks datacenters out from the rest of its operation, breaks down data by individual datacenter, and is even trying to get to grips with the environmental impact of third-party datacenters.

Microsoft too breaks down data by region, and Amazon continues to innovate and enable renewable energy projects on an extraordinary scale.

There is notably more effort across the board to provide useful information.

Sunnier Skies Ahead? Cloud Giants Dial Down The 'Greenwash'

Computing's 2024 cloud sustainability research reveals positive changes in some of the environmental data provided by big three cloud vendors

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Standards and Policies

GCP and Azure scored almost identically here, taking 9 and 8 points respectively out of a maximum of 10. A differentiator in this quadrant is the Science Based Targets Initiative. Microsoft and AWS made commitments to SBTI several years ago, but have since had them removed, meaning that they pledged a target but then failed to provide the detail of how they intended to get there.

Both Amazon and Microsoft were invited to comment about this. Amazon referred us to a statement published last August and Microsoft to one published in March this year.

AWS scores badly across multiple metrics in this quadrant. The company provides next to no detail on how it aligns and furthers the UN Sustainable Development Goals (SDGs), and has a less developed toolset than its competitors for its customers to assess the impact their use of AWS has on their carbon footprint.

When Computing asked Amazon to comment, the company said it is currently assessing how indirect emissions can be incorporated into this tool.

Environmental reporting standards for Amazon suppliers are less stringent than those of Google and Microsoft, although Amazon has committed to ask suppliers to report on carbon emissions from next year.

Emissions and water

This the most heavily weighted aspect of our analysis, with 20 points available. Interestingly, all three hyperscalers score almost equally, with GCP and Azure scoring 10 points and AWS 9.

The biggest difference is in the criterion of GHG emissions reduction against targets, where Google picks up four of the available five points. The organization has cut its scope 3 carbon emissions, to less than they were in 2018, despite growing as a business. Crucially, the company managed to reduce its location-based scope 3 emissions. See here for a detailed explanation of the difference between location- and market-based emissions.

Google was less successful at reducing its scope 1 (which doubled due to the company including a source of emission that hadn't previously been included) and scope 2 emissions, which are primarily made up of emissions related to electricity consumption.

Microsoft only picked up three points here because all emissions categories grew, but by less than expected relative to company growth. The growth in scope 3 emissions was also partially explained by more reporting accuracy. This picks up emissions that have previously been unreported, so whether it represents genuine emissions growth is a moot point. The company purchased sufficient offsets to present this a small reduction in emission - more on this later.

In common with Microsoft, Amazon's reporting presents a narrative of slightly reduced overall footprint despite much higher company growth. Like its closest cloud competitor, Amazon's emissions have grown; the impression of a reduction has been enabled by means of offsetting, mainly of scope 2 emissions. Crucially, Amazon doesn't provide a reason for increased emissions, which is why it only scores 1 point out of the available 5.

AWS picks up points on built emissions and innovation. AWS has pioneered the use of recycled steel and lower carbon concrete in its datacenter construction, and this will scale. Given the fact that these foundational industries account for around 20% of global CO2 emissions, a company of Amazon's size and scale de-risking the use of more sustainable building materials could prove to be a genuine driver of global emissions reduction. Amazon's Graviton-3 chip could also be a game changer by enabling much more efficient computing.

AWS also picks up a point against its competition in the water metrics, although only by providing a Water Usage Efficiency (WUE) rating, which neither Microsoft nor Google provide. However, Amazon does not reveal overall water consumption.

Google chooses to provide this data in gallons rather than liters. Google datacenters consumed 5.2 billion gallons of water in FY22. Microsoft's water consumption over that year is given at 6,399 megaliters. When you convert Google's gallons into megaliters (one megaliter = one million liters), you arrive at 19,759 megaliters.

Google's vast water use is likely to relate to datacenter cooling, an area where Google provides less information than either Microsoft or Amazon. In terms of our research, it's Google's biggest weakness. The decision to publish in gallons rather than liters looks cynical.

We reached out to Google for comment on the topic of water use and a spokesperson responded:

"We constantly look for more efficient ways to use water, using data through our water risk framework (released December 2023) to understand local hydrology and engaging with local experts to find the best solution for each community.

"We also invest heavily in our datacenter systems and operations, which we're continually reviewing and improving, to maximize efficiency with the water that we do use. And wherever we use water, we are committed to doing so responsibly. This includes using alternatives to freshwater whenever possible, like wastewater, industrial water, or even seawater. We utilize reclaimed or non-potable water at more than 25% of our data center campuses."

Circular economy

Google wins this quadrant hands down. The company earns points by providing data on the proportion of their datacenter equipment, which consists of refurbished stock (21%), and on having a high landfill diversion rate. Google provides more evidence of circularity within its operation than its competitors, and both Microsoft and Amazon provide limited data on waste, particularly electronic waste. There is narrative from both companies about efforts to recycle components, but insufficient data to make a judgement.

Both Microsoft and Amazon were asked for comment. Microsoft did not offer any additional comment, and Amazon provided an absolute number of 379,635 components used in datacenters coming from refurbished stock in 2023. This is good, but as we are unable to judge the proportion of overall components this constitutes (given AWS's size it is likely a vanishingly small proportion of the total) it has not changed Amazon's score in this metric.

Transparency

Here, Microsoft and Google both take 7 points out of an available 10, while Amazon takes 4.

Amazon's data is harder to access than its competitors'. Finding data on location-based carbon emission involves finding assurance letters in the main report appendix, and then finding the appendix of those letters where the calculations are shown. None of this is signposted from the main data tables in the report – the reader must seek them out.

Microsoft also loses points on carbon accounting, because the company admits to having used unbundled renewable energy certificates (RECs) to offset their increased emissions. This is carbon accounting at its most cynical. Unbundled RECs are contractual instruments, but separated from the unit of renewable energy that once accompanied them. They are disconnected from the supply of renewable energy, so cannot credibly be used to offset demand.

Microsoft says within its report text that it plans to phase out the purchase of unbundled RECs, presumably because the company is aware of this credibility gap. What is disappointing is that it's using them at all. Power Purchasing Agreements (PPAs) are a much more credible offset because they drive additionality.

All three of the big cloud providers show a gap between their stated ambitions to be carbon neutral (or negative) and water positive in their operations by 2030 (2040 in Amazon's case) and the reality of their environmental impact. Microsoft has even pledged to have neutralized all historical carbon emissions by 2050. The sustainability gap varies in size from cloud to cloud, but this year, Google has unquestionably made the biggest leap forward in terms of progress towards target.

This article originally appeared on our sister site Computing.