Amazon's carbon footprint spread 18% in 2021

How's that renewable energy transition going?

Amazon increased its total carbon footprint by 18 percent during 2021, despite promises to transition entirely to renewable energy for its operations before the end of the decade.

In its defense, the cloud services giant said it has been working to increase efficiency, and still aims to hit net-zero carbon emissions by 2040.

In Amazon’s 2021 Sustainability Report (available here), the megacorp details progress towards lessening its impact on the planet, but admits that its continual growth – especially in its Amazon Web Services (AWS) cloud division – is hampering efforts to decarbonize.

The company blamed COVID-19 on the shift, saying it had scaled its business at an unprecedented pace during the last two years to sell more stuff to customers during the pandemic. From early 2020 to the end of 2021, Amazon claims it doubled the size of its fulfilment network, and creating more than 750,000 full-time and part-time jobs worldwide.

The growing commercial scale means that Amazon was required to keep on building new facilities, both in the form of warehouses for its online consumer goods market and additional datacenter sites for AWS expansion.

In fact, AWS grew revenue 33 percent year-on-year to $19.73 billion during calendar Q2 of 2022, as disclosed in its recent financial figures for the quarter, with operating profit up more than 36 percent year-on-year to $5.7 billion.

Amazon’s reported carbon footprint data shows that it increased Scope 1 emissions from direct operations by 26 percent during 2021. However, its Scope 2 emissions from purchased electricity fell by 23 percent, likely due to its increased use of renewables.

The company’s Scope 3 emissions from indirect sources – such as the supply chain – rose 21 percent, of which 46 percent was accounted for by buildings construction, and purchased goods such as servers and other hardware.

However, Amazon said it remained focused on improving energy efficiency through various means, and despite all of the growth through 2021, its carbon intensity – the CO₂ emissions produced per kilowatt hour of electricity consumed – decreased by 1.9 percent, marking the third year in a row this has improved. This is a line that Amazon has been pushing for a while now, and it claims that over time, continued decreases in carbon intensity can lead to lower absolute emissions.

AWS has spent considerable resources on boosting efficiency, the company said, and listed its rollout of Arm-based Graviton EC2 instances that are claimed to use up to 60 percent less energy for the same performance as one such measure.

According to Amazon, AWS has worked with suppliers to optimize the cooling medium used in its datacenter cooling systems, leading to a new medium with twice the service life that allows air to pass through more easily, saving fan energy. This is claimed to have reduced the energy use of cooling equipment by 20 percent.

Another step that the AWS team has taken to improve efficiency is changing its datacenter architecture to do away with a monolithic, centralized uninterruptible power supply (UPS), and instead integrate smaller battery packs and custom power supplies into the equipment racks. These changes allow its datacenters to reduce losses from energy conversion by about 35 percent, it claims.

AWS is also seeking to minimize water use in datacenters, and said it uses a method whereby outside air is cooled through an evaporative process and pushed into server rooms to keep hardware at stable operating temperatures. This approach means that even its largest data centers capacity will use on average about the same water in one year as 25 US households.

The company claims that it managed to reach a figure of 85 percent renewable energy for its entire operations during 2021, and is now on target to achieve its goal of becoming 100 percent renewable powered by 2025, which would be five years ahead of the original target it set itself.

Amazon said that while some of its actions and investments deliver immediate carbon savings, others will take years to bear fruit, and that “the path to net-zero carbon has many obstacles.”

Some of these obstacles include developing more sustainable transport infrastructure in its e-commerce business, decarbonizing the supply chain, and developing more sustainable ways of constructing buildings such as warehouses and datacenters.

For the latter, Amazon said it has invested in CarbonCure Technologies, a company that enables concrete production with a lower carbon footprint, and Brimstone Energy, which aims to make cement carbon neutral by using calcium silicate rocks. Meanwhile, its design standards for new US datacenters now require concrete with a 20 percent reduction in embodied carbon versus standard concrete, and Amazon said it will expand this requirement to the rest of the world.

In transport, the company said it plans to make half of its shipments net-zero in CO₂ emissions by 2030 by creating a worldwide fleet of zero emission vehicles. It claims to have ordered at least 100,000 electric vehicles from manufacturers such as Rivian, but said it is being held back by a lack of charging infrastructure that does not yet exist at the scale needed by Amazon to serve customers.

Overall, Amazon believes it is making progress on sustainability, but as its VP for Worldwide Sustainability Kara Hurst writes in an introduction to the report, it recognizes it still has a great deal more to do.

“Our everyday actions to deliver progress are in service of achieving long-term, systemic change that improves the well-being of people, communities, and the planet,” she said. ®