Sustainability is becoming an ever more important topic, and all fields of life have to figure out what they can do to contribute to reducing their own emissions footprint.

The situation is no different with advertising. Considering that an average internet user sees 5,000-10,000 digital ads daily, the numbers add up. Serving and displaying these ads to the end user all require energy. We have implemented a CO2 calculation feature in our platform, which helps you realise the savings you get using NEXD's creative and ad-serving tools.

To make it easier to find the information needed, this article has been broken down into parts:

  • How do we calculate CO2 emitted by advertising campaigns?

  • How does the weight of creatives influence the energy needed by ad-servers?

  • How are the CO2 savings in the Campaign Manager calculated?

  • How are Nexd creative solutions and ad-serving better for the environment?

  • How do data centres contribute to advertising emissions footprint?

  • Did you know you can use Nexd as an ad-serving tool only as well?

How do we calculate CO2 emitted by advertising campaigns?

The primary polluting services are servers that handle requests and send the visuals to the viewer. Nexd's services calculate the ad weight and multiply it by how many times we have had to serve the ad files. Based on the research by the International Energy Agency (IEA) and other agencies shown in the studies, we have calculated that on average 1 GB of network transfers requires 0.06 kWh of energy.

To calculate the energy requirements for each ad, we consider the energy usage in each market where the impressions will be shown. Based on that, we will calculate how much CO2 energy production creates in each country


For example, an ad campaign with a video of 100 million impressions running in the United Kingdom will generate around 4 tons of CO2 using normal ad-serving solutions.


How does the weight of creatives influence the energy needed by ad-servers?

We know that data servers can be quite polluting as they handle A LOT of data and serve it worldwide. Most of the time, the data bandwidth marks how much the data servers use energy – gigabytes (GB) served equals the energy used. We found that the most accepted number was 0.06 kWh per GB delivered. Therefore every ad should be as lightweight as possible and make as few requests as possible so that the server side doesn't have to initiate new deliveries too often. 0.06 is quite a small number if we look at it as one ad. But every ad request is the whole ad downloaded again and again. So a 1MB advertisement served 100 million times is 1000000 GB bandwidth.


An ad campaign with a video of 100 million impressions running in the United Kingdom using Nexd ad-serving solutions will generate around 1.5 tons of CO2.


Nexd shows in all of its analytics reports (available for full analytics access users) the CO2 emissions saved using Nexd ad serving. Nexd ad serving is based on 100% renewable energy, and in cooperation with our infrastructure partner on markets where renewable energy is not well attainable, we invest in carbon offsets or removals on markets.

How are the CO2 savings in the Campaign Manager calculated?

The calculation takes into account the following variables:

Size - the size of the creative's original files (e.g. original pack of HTML, or original assets of others) in kilobytes

Impressions - how many impressions the creative has served

TO_GB - modify the size to GB (size in gigabytes)

AVG_GB_TO_KWH = 0.06 - energy usage to transfer 1 GB (kWh - kilowatt hour)

KWH_TO_gCO2 - Regional energy production emissions (e.g. the UK 266g per kWh)

Formula: (SIZE x IMPRESSIONS) / TO_GB x AVG_GB_TO_KWH x KWH_TO_gCO2

  • The saving of serving an HTML5 banner (avg. weight 1300kb) 100,000 impressions vs serving a Nexd banner (avg. weight 200kb) is 6.5 times.

  • An HTML5 banner in this case will emit 2kg of CO2 and a Nexd banner will emit 319g of CO2 - that's a saving of 84%!*

*It is important to mark that the banner size may vary depending on

the assets added to it.

Depending on the assets used and markets where ads are served, our conservative evaluation is that you are able to save between 25-50% on the CO2 emissions of your ads.

How are Nexd creative solutions and ad-serving better for the environment?

The technical difference between Nexd's solutions and HTML5 comes from our processing source. Nexd's creative solutions use WebGL technology, which uses GPU for processing instead of CPU. CPU stands for Central Processing Unit, and everything that happens on a website uses that as a resource. Nexd solutions use GPU, which means Graphics Processing Unit, which helps show our ads without having to fight for other resources. This also reduces our ad load time. Additionally, this helps us to have a good user experience on all publisher sites, as the impact of performance is minimal.

Nexd's ad serving has been certified by Green Web Foundation to run fully on renewable energy. Our serving side ad server is Cloudflare. Cloudflare's market-based Scope 2 emissions are zero for 2020 as a result of the company's renewable energy purchases. Cloudflare purchased renewable energy attribute certificates (I-RECs, RECs, REGO, and others), through its partner 3Degrees, equivalent to Cloudflare's global facilities and network energy usage. All purchases were consistent with RE100 technical criteria. The ad server info can be found here.

How do data centres contribute to advertising emissions footprint?

Most of us don't actively think about what it takes to make "the internet happen". However, there are physical places with hundreds of data centres where data is stored, which deliver our emails and stream our films. The truth is that all these activities require a lot of energy and emit CO2. As described by Yale Environment 360, "the processors in the biggest data centres hum with as much energy as can be delivered by a large power station, 1,000 megawatts or more. And it can retake as much energy to keep the servers and surrounding buildings from overheating." Today there are efforts to make data centres greener and push them to use more renewable energy.

Data centres - home of the internet

Did you know you can use Nexd as an ad-serving tool only as well?

As Nexd is also an ad server, you don't have to build your ads with us; you can benefit from our tool still. Uploading and exporting creatives through our Campaign Manager, the creative size will be optimised thanks to our WebGL technology, and the emission savings will also apply to your external creatives.

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