The Week in Green Software: New Research Horizons

Environment Variables

This Week in Green Software has Dr. Daniel Schien from the University of Bristol, UK, joining host Chris Adams to talk about old research, recent news, and future prospects all revolving around digital sustainability. This conversation touches on some of the work Daniel has done in the past (and plans to do in the future) as well as their thoughts and reckons on this and how it can be used to steer our efforts towards a sustainable future. Together, they cover topics such as streaming being the new flying, and some ways in which new research has changed their perspectives on some problems in green tech.

Learn more about our people:

• Chris Adams: LinkedIn | GitHub | Website
• Daniel Schien: LinkedIn

Find out more about the GSF:

• The Green Software Foundation Website
• Sign up to the Green Software Foundation Newsletter

Resources:

• The True Climate Impact of Streaming - About Netflix [04:06]
• The carbon impact of streaming: an update on BBC TV's energy footprint [05:07]
• Does not compute: Avoiding pitfalls assessing the Internet's energy and carbon impacts - ScienceDirect [21:10]
• Evaluating Sustainable Interaction Design of Digital Services | Proceedings of the 2019 CHI Conference on Human Factors in Computing Systems [40:50]
• A low carbon kubernetes scheduler — University of Bristol [41:47]

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TRANSCRIPT BELOW:
Daniel Schien: If we are saying streaming is bad and instead consumers jump into their car and go to the cinema, that would be the worst thing that people could do. And same if we are saying streaming is bad and consumers swap to terrestrial broadcast, makes hardly a difference in the short term to the energy consumption that is associated to the delivery of the service.

Chris Adams: Hello, and welcome to Environment Variables, brought to you by the Green Software Foundation. On our show, you can expect candid conversations with top experts in their field who have a passion for how to reduce the greenhouse gas emissions of software. I'm your host, Chris Adams. Welcome to another episode of The Week in Green Software, where we bring you the latest news and updates from the world of sustainable software development. I'm your host, Chris Adams. In this episode, we're joined by Dr. Daniel Schien, a member of the Green Software Foundation. Daniel teaches and researches sustainable software at the University of Bristol, England.

Hey, Dan.

Daniel Schien: Hi Chris.

Chris Adams: Dan, if any of our listeners lurk on the Green Software Foundation forums, or the kind of IETF E-Impact mailing list, they might be familiar with you. But for folks who are new, would you mind taking a second to introduce yourself to the pod for our listeners, please?

Daniel Schien: Sure. Thanks for having me. My name is Daniel Schien, and I, as you said, teach and research at the University of Bristol in the United Kingdom. I'm a computer scientist and work here in the Faculty of Engineering, researching questions of sustainability of ICT. And here in Bristol, I'm part of a small but dedicated group of researchers looking at the environmental impact of ICT.

Chris Adams: Okay. And I did a bit of research before this call and I realized the first paper I saw from you was back in 2011, researching the dynamic carbon footprint of digital services back in 2011. So it sounds like you've been doing this a while and you've worked with a number of organizations in the industry as well.

Is that correct?

Daniel Schien: Yes, that's true. Indeed, I joined the University of Bristol at the end of 2010, working on a project for the Guardian newspaper, actually. And at that time, they were interested in understanding the transformation of their business from a paper-based delivery to a digital delivery, reading the news online. And at that point there were no methods, no existing similar analyses of environmental impact from the distribution starting at data centers over networks to user devices. And in this void, we helped to come up with an assessment that can compare the quite well understood print side of delivering news with the digital version.

Chris Adams: Wow. Okay. And you've worked with a few other organizations as well. And I think we're going to touch on that a little bit later on. So wow. Thank you. The little story about the Guardian. I had no idea that the Grawn was doing that stuff so long ago already, actually. Okay. Um, cheers for that, Dan. If you're new to this podcast folks, as mentioned before, my name is Chris Adams.

I work as the chair of the policy working group at the Green Software Foundation. And I'm also the executive director of the Green Web Foundation, a Dutch nonprofit working towards an entirely fossil-free internet by 2030. I'm also going to share that whenever we mention a story or a project or a paper in this podcast, we'll do everything we can to find a link so you can actually research some of this yourselves and learn somewhat more if anything caught your interest.

And if there's something that you heard us talk about that you didn't see in the show notes, please do send us an email or get in touch and we'll do everything we can to capture that information and make sure it's available for everyone else. Okay, Dan, are you sitting comfortably?

Daniel Schien: Yes, I am. Thank you very much.

Chris Adams: All right, I think we should begin then.

So a few years back, one of the tropes that just would not die when people started talking about sustainability in the digital realm was this idea of streaming being the new flying. And, um, I saw your name linked to some work that was published in 2021, uh, working with Netflix that actually, in my view, helped shed some light into this and, uh, hopefully might put away some of the kind of poorly written part articles that you often see in the newspapers.

Could you talk, talk a little bit about some of this work that you did? Cause this was one of the first places I really came across your more mainstream work and it, I found it really interesting, actually.

Daniel Schien: Sure. So I mentioned earlier that my, my work here in Bristol on the sustainability of digital media started working with the Guardian and they wanted to understand the transition from print to digital. A couple of years later in 2015, we then worked with the BBC who also wanted to understand a similar transition. For them, it was the transition from terrestrial broadcast of BBC television to IP-based delivery. There is a broader context within which this transition happens. Terrestrial television, terrestrial broadcast uses up spectrum, and that spectrum is a scarce resource. And so there's a, there's an interest in potentially freeing the spectrum up for other purposes. So that's one of the drivers and the other is of course the affordance that IP-based delivery provides. You're moving from a broadcast mode to a unicast mode and, and enabling a lot of new ways of consuming. First of all, you can, you have video on demand as we know, and the other is more interactive forms of media. However, there was a concern about the environmental implications of it. And this concern was, was born just out of a lack of knowledge. At that time, the colleagues at the BBC, they, of course, had very good understanding of the energy consumption of the servers they were operating themselves, but what they did not have a firm grasp on was the energy consumption in networks that transport the data from data centers to the users and then the energy consumption of the devices in the homes. And this product system is, in its structure, relatively similar to the one that delivers the Guardian News Media. So we could leverage some of the methods that we developed in the work before to, to then come up with an estimate, an assessment model that then helped develop an estimate of the energy consumption for delivering BBC television, uh, over IP, but at the same time we delivered this, uh, we used this model to assess the impact from cable and from satellite as well, including terrestrial. And then we were able to also complement this with scenarios of how this might change in the future as the technology becomes more efficient, as the energy transforms, becomes more green, and as user behaviors change. So, so this was, this was a really, I think, yeah, a very successful collaboration. And there's a couple of things that we can dig into later on that are interesting here when it comes to the interpretation of those assessments. But one of the, one of the great things that came out of this was that at that time, that was one of the first studies that worked with an organization that provided the content and so had primary data of the impact in the infrastructure to some degree. And that was an important advantage compared to other work that is based purely on secondary data, on publicly available data, that it provides maybe a more robust.

Chris Adams: Yeah, you get to speak the people, surely. You're asked, you're asked like, "Hey, have I got this data right? Am I understanding it correctly?" And presumably, assuming they're being transparent and honest with you, you've got much greater access about what assumptions are going into that, rather than what you see elsewhere.

Yeah, that makes total sense, actually, Dan.

Daniel Schien: Yeah. So, and then a couple of years later, we, we had, um, a conversation with the uh, Responsible Media Forum, a small stakeholder representation run by Carnstone and, and they said, "can we somehow create a self-service assessment tool that lifts the, the methods that were developed in the work with the BBC, but makes them available for other organizations to also assess the environmental impact from the delivery of their

Chris Adams: Oh, wow.

Daniel Schien: services?" That was then the start of the DIMPACT project.

Chris Adams: Oh, I see. I hadn't really realized that there was a link going all the way back to public service broadcasting, essentially, in that model, actually. Wow. Okay. Huh.

Daniel Schien: That was the idea. And now many global media organizations are using this tool to report on the environmental impact of the distribution side. So I think this is a great success story. I always say that our role as academics is to create knowledge that we want to make the actual impact more transparent. And in this way, we have enabled the organizations providing those services to do exactly that.

Chris Adams: Wow. Cool. Thank you for that, Dan. All right. So there's a couple of things that I'd like to jump into there. And it sounds like... I thought I was just going to be asking you about Netflix, but it sounds like there's a whole set of different media that we might be thinking about and where there's changes and surprises along the way, basically.

I've got to ask you, were there any kind of counterintuitive findings that you had there? Because I immediately, for example, when you spoke about the idea of switching from analog to digital, I assume there's an energy impact in being able to switch off all the analog TV broadcast, for example, right? Is that something that people talk about?

Cause I hadn't really put those two together until you spoke about that, but surely that's actually going to be an impact, right?

Daniel Schien: Yes, absolutely. So, so this is maybe one of the nuances that, that we can spend a bit of time on. In the publication, in the academic publication, that, and I'm sure you will link to it in the show notes, there's a graph that compares the energy intensity of those four different modes of delivery of television from the BBC, so IP, cable, satellite, and terrestrial. And even though they, they differ, so between, if I remember correctly, between 60 watt-hours to 180 watt-hours, that's in 2016. There's a potential step in the interpretation of those results that consumers might take that needs more support. If you see this graph, you might think as a consumer, "if I change from streaming to watching something via terrestrial broadcast, I am going to save 100 watt-hours per viewer hour." However, that would not be a correct interpretation because all of those delivery modes, they are provided by an infrastructure that is inherently inelastic in its energy

Chris Adams: So you're talking about always being on. So if I've got like an analog television, even though I'm turning off the analog television, it's still broadcasting. So the same, so you've got a lot of the same analogs, sort of discussions we have now about "should I, is me using Netflix less, does that have an impact at the network level?" We have similar comparisons. It sounds

Daniel Schien: Exactly, exactly. So it's not that... your television, if you turn that off, you're saving energy right now. However, the modem in your home, that's going to stay on even if you're not streaming. The routers in the network, they hardly change. So in your ISP network, they're hardly changing the energy consumption. The terrestrial antenna network outside of your home in the country is not going to change its energy consumption. So on a very short term, your behavior as a consumer between swapping between those different modes of, of consuming television has hardly any difference outside of the home. If you are moving from a television to an iPad or to a phone, that will make a difference, but it won't make a difference outside of your home.

Chris Adams: Okay. I'm glad you said this because I ended up being, uh, on a podcast with, of all places, the Daily Mail, who really wanted to basically, wanted me to say that you're an absolute terrible person for watching Netflix. And if you watch twice as much Netflix, you are twice as bad a person. And, uh, I, I ended up basically not saying what they wanted me to say, which was that in context, not going, it's not going to be that much of a difference.

And yes, you probably going to have the impact at the device level rather than the other parts. I'm really glad that there's an actual doctor saying that as well now, because I feel slightly more validated in actually making the argument because yeah, it does seem somewhat counterintuitive, but it does seem like a kind of somewhat actionable thing for someone to be able to do.

Daniel Schien: Yeah, it's, it is unfortunate that the debate is now being tainted by a lot of, a lot of bias that comes in. You've got, it's been elevated on a very prominent level. There's a discourse that everyone now has, has an opinion on, and everyone has a right to have an opinion on this, but what you have, for example, in the media, you've got a bias to tell sensationalist stories, right?

Headlines that are emotional, that evoke emotions, they sell better. And there's sadly such an enormous amount of attention-grabbing exaggerations out there. It is, it's very sad, actually. And I've been subject to this. There was a Guardian interview that I spent several days in preparation, trying to provide enough data to have a really nuanced perspective on what is known about the carbon impact of streaming, but it's been completely contorted in the final article. That was very upsetting, actually. And I've been in touch frequently with newspapers when the reporting of work of Environmental Impact of not just streaming, but other forms of digital media and ICT services was just represented in a very wrong way, a headline grabbing sensationalist. So there's no, no silver bullet to preventing misinformation.

It is really a Sisyphus kind of work. These tropes, they come back again and again, and there's some, there's some work where the scientists that carry out the work apply methods that aren't robust, that are still under development, and that that happens. That is the nature of, of research and of knowledge evolving over time, our understanding improving, but then there's, once the work has been written down in academic articles, then there is the interpretation and the presentation of that work in the public sphere, or in a political sphere or elsewhere, that, that is, that potentially provides another layer where there's risk for misrepresentation.

Chris Adams: This is particularly relevant given the fact that we're seeing an explosion of laws being passed specifically around this stuff right now, both for and against a bunch of this stuff. We've seen the, actually just this week, I think even yesterday in Germany, where I live, we've seen what translates into English as the Energy Efficiency Law, specifically referring to data centers.

And you see the same thing at the European level as well. So you do see a real role for people's interpretation of this. And I actually wanted to ask you, because we spoke about some things which are like counterintuitive. I wonder how much of this you think might be related to the kind of mental models that people have, because a lot of the time, the mental model that you might have when thinking about digital sustainability, or like build it using a digital service, I can see why you would bias it towards the use that I see being the thing that infor that has the most impact, for example.

And I wonder, are there any papers or any reports or any guides that you've seen that help form a different men- mental model? Does it make sense of this, for example?

Daniel Schien: Yeah. So I want to maybe prefix this by saying that I don't want to be interpreted by saying that there's no environmental impact from our consumption of digital, of digital media or of ICT goods. There is uncertainty in the existing assessments. Um, but I think those that position the, the impact of the sector, the present impact of the sector in the order of 2 to 4%, um, they're probably reasonably robust to work with. And, and those 2 to 4%, they are high enough that the professionals working within the sector need to do something about it.

Chris Adams: Now this is two before, 2 to 4% of global if, of carbon emissions?

Daniel Schien: Exactly, exactly. Yeah, so of the 50 or so gigatons of anthropogenic greenhouse gas emissions per year, about 2 to 4% are allocated to the use of ICT services and the making of devices, and that is, and that's too much. We need to do something about it, especially as the rest of the economy hopefully decarbonizes and as our use of ICT increases.

So, so the dynamics that are at play here going forward, they're really, we need to pay attention to so that we can keep this in check. And at the same time, it is relatively small so that when we are trying to do what we can to reduce carbon emissions, then we need to prioritize our actions such that we have a firm grasp on, on the decarbonization of, of the sector. And so one, coming back to video streaming, if we demonize video streaming and the consumer who has to rely on guidance for action, that is straightforward to put into action if we are saying "streaming is bad" and instead consumers jump into their car and go to the cinema, that would be the worst thing that people could do. And same if we're saying streaming is bad and consumers swap to terrestrial broadcast, it makes hardly a difference in the short term to the energy consumption that is associated to the delivery of the service. I

Chris Adams: I'm glad you mentioned this one about terrestrial because I realized until you mentioned the BBC thing and the fact that people switch off a bunch of spectrum, I hadn't realized that there's actually a kind of net impact on that because you do see the same thing with, uh, cellular right now. We have 4G and 5G, and we are now seeing people switch off like old 3G transmitters, and there's like an energy saving from that. But in many ways, that's something that because it's seen as such a kind of industrial level, it's a kind of implementation detail. We're not really aware of a bunch of that stuff. And I feel like that's actually an interesting kind of angle that you presented on that.

So if I can move on a little bit further from this, so you did a bit of work with DIMPACT, I am pronouncing it correct. Is DIMPACT the way I should be pronouncing it? Is that okay?

Daniel Schien: DIMPACT is the pronunciation I use, yeah.

Chris Adams: Okay. Now, and DIMPACT, as I understand it, you mentioned there was a firm called Carnstone, they provide like services around this.

But the methodology is entirely open for other people to actually implement and use as well. And as I understand it, you are the advisory council with some of that, along with a number of other academics. So there was some guidance you were sharing for them as they were developing that. Is that correct?

Daniel Schien: Yeah, so indeed I chair the academic advisory board, and so the advisory board is, there's the methodology document and, and the exact constitution of the panel is there. There's sometimes the personnel changes, so it's best to see there who's there, but I think that the people that we work with are, uh, the absolute top academics, um, in this space, for example, Eric, Eric Masanet from the University of California in Santa Barbara is, is on the advisory board, um, or has been on the advisory board and he, together with Jon Koomey, have released an article in Jewel magazine a few years back, where they identified some of the principles that can lead to a misinterpretation of the academic impact of digital media, actually, that's really worth looking at.

Chris Adams: I think you're referring to, the paper is called Does Not Compute or something along those lines. Yeah?

All right. We'll share a link to that. Cause as, I found that really helpful as well for me to essentially make sense of this as someone who's not an academic. So actually on this subject of changing your mind and, uh, in face of the data, I should probably ask you, you've been researching this for a while, and, uh, we've already come up with a few kind of counterintuitive things.

Are there any areas where you've really changed your own view on something, where you thought something was the case and now there's more data available or the research has improved? You're actually thinking, "actually, that wasn't the lever for change I thought it would be. And there's somewhere else I should be looking instead."

Maybe you could talk a little bit about that, because this is one thing that. I think we're probably going to have to do more and more over the coming few years as the picture becomes clearer, both at the research and the industry level, as more things become more open.

Daniel Schien: So, less of a surprise moment is the gradual transformation of where I believe the emphasis of the attention should go, I started working on, on trying to, to, to understand the environmental impact of, of digital media now, 12 years ago, and with a keen focus on the use-phase energy consumption, because from a methodological perspective, it was one that, that was set in a, in sort of a gap, it's a distributed system where you've got data center networks and user devices, but the availability of data is poor.

No single party in this system has access to primary data. No single party can know what is the energy consumption in the data center because you can't get a power meter there or in the network or in the user devices. And so there's, methodologically, there was really quite a rich set of questions to explore. Um, now, the understanding of the environmental impact from streaming video has solidified. There's some variability around it and some uncertainty. However, the great new frontier is the impact from the making of the devices and, and in particular now with the electricity production in many countries becoming greener, there's a great success in the UK with decarbonizing electricity and hopefully we can continue along that trajectory. But as the electricity becomes greener, it becomes more and more important to understand and mitigate the carbon impact from the making of devices and, and we said, we spoke before about the interpretation for consumers. So when someone opens the newspaper and then they see something about streaming or about digital media, it is the metabolism of devices.

It is the frequent purchase of new devices that now is one of the key areas of environmental impact that consumers can actually do something about.

Chris Adams: When you say metabolism of devices in that way, you're talking about essentially built in refresh cycles or obsolescence, like a new iPhone each year or something along those lines, yeah?

Daniel Schien: Exactly so. I think that's, that is something where all consumers can have a meaningful impact by protecting the screen of their phones so they can last longer, and, and by, by not being swayed by the latest marketing stories to buy a new phone that is marginally faster, I think that that's something where, where, where the consumer can do something about it.

But the sector, the professionals within the organizations building the services, designing the services, of course it's their responsibility to do this as efficiently as they can. And, when I'm sitting here on my laptop and I hear the fan kicking in, then I'm often looking what are the threads that are currently ongoing.

What tasks are running there in the

Chris Adams: What things can I switch off on my computer to make it stop blowing away, right?

Daniel Schien: Yes, exactly. And sometimes you've got, you've got processes that are consuming CPU cycles where I'm pretty convinced there's waste going on. So what are some good examples? So I've got a mouse from a well-known manufacturer and it comes with a device driver, but the device driver consumes sometimes up to six gigabytes of memory. Because there must be a memory, there must be some sort of memory leak.

Chris Adams: This is for the mouse, right?

Daniel Schien: It's...

It's this one here. It's a good mouse,

but it is just carelessness. There are too many examples that I come across where the software running on my machine is made in a careless way. And I think the work that the Green Software Foundation does there can really help in increasing and improving the efficiency of software that runs on a single device.

I think we need to think more holistically and consider the entire system, not just on, on one device, but the whole balance between servers, networks, and use devices, but there is, there's still a rich space to make things more efficient.

Chris Adams: Okay. So we've got one about, so there's steps you can take at the use phase there. There are things you, as you describe, there are steps you might take in the design of something to make it run more efficient in use. And then there's another set of interventions you describe, which are design interventions you might make to reduce the need to cycle hardware quite so often, for example.

And it sounds like the former, where you might just make your code run more efficient, that's really common and relatively well understood, and we have some incentives aligned there. But this next part, that's something of a kind of newer horizon because the approaches you might take to essentially design something so it doesn't need to be replaced so much, you've got different drivers from an economic point of view, and we haven't figured out all those yet.

Are there any examples that you would point to that give an idea of where some of this might go? Because we talked about things like the Fairphone before as one example, and I know there are some cases in other sectors now. The first thing I think of is maybe like the framework computer, for example, which is designed to be taken apart or designed to be modularly put together.

Do you reckon there's some legs and stuff like that? Or yeah, maybe, maybe you could like elaborate on some of that stuff there.

Daniel Schien: I have the feeling that a cloud-based distribution model or, or a model to run software has got an enormous potential to reduce the impact for, from the manufacturing of devices and also for also for the runtime energy consumption. Just the maintenance of applications that are distributed over a traditional model where you've got a sort of a fat client living somewhere on a customer device for an organization constructing software has enormous implications for the, for the, for the maintenance, yeah, for the, for the ongoing support.

Whereas if you have a, um, if the, if the software runs in the cloud, um, then just by the, by the interface um, that you have over the web, um, you, the, the, the, the cloud software provider has, has, has much higher control, um, over the anatomy, the architecture, and the implementation and the evolution of the software to get, to make it more efficient.

Chris Adams: So to make some of this more concrete, let's say that you wanted to do something at a hardware level. You're like, yeah, you could buy a really fast machine, for example, but there are tools where we work. We use Gitpod because one of the reasons is that basically shifts all the kind of development work into a machine in the cloud.

And there's things like GitHub Spaces, which do this idea of shifting the work to a more centralized place. That's what you're, it sounds like you're talking about, and that might be easier to green, for example, as well?

Daniel Schien: Yeah, uh, so. I think there's probably the devil in the detail. Not all applications, um, will, will suit this model of a, of a cloud-based, um, distributed system equally well, but if you can have a thin client to, to just access that cloud service for many applications, there, I believe this is the opportunity to then hold on to this thin client for longer.

Chris Adams: Okay. So there you have it then. All right. So that's one of the ideas that we might be looking at. And there's a bunch of other questions about, okay, which, whose cloud are you talking about here? And there's a sovereignty issue there. And if you're going to concentrate with it, how can you be sure that you're going to get the data out of it?

Or there's transparency issues and things related to that, which you've, I think you've alluded to elsewhere. Are there any areas in the research community right now where you see some, I don't know, opinions or ideas that are probably a few further along than where the rest of industry might actually be right now, that you think is probably something that people could spend more time looking at? Because I know that you read papers and you publish papers on a regular basis, but we also see that there is a gap between what being discussed at, say, HotCarbon or the E-Impact events, for example, and then what's more mainstream and like the industry at present. Thank you.

Daniel Schien: So, so my own concern, has moved from trying to understand what the current impact is and in the past, relying on accounting style methods to a concern of how can we robustly enable all the stakeholders to take action that can result in the reduction of that environmental impact. And that includes the consumers. What can I, what concrete decision support, what guidance can I give to consumers when they decide between different options to consume digital media? What can I say to the designers, to the engineers building those services to do this in the least environmentally impactful manner? And infrastructure operators, is there something that they can do so that we are moving towards decarbonizing the system? And what I said before, the concern that there is a high base power consumption of devices and the lack of energy elasticity. There is the overhead from the manufacturing of devices that, that lock you in, um, to amortize this impact over the lifetime, um, of the, of the device that has in, in my mind eroded the confidence in the set of existing accounting-style methods to really provide that decision support in a robust way. I think one of the key questions that we still have to solve is that of electricity consumption and carbon intensity of electricity. There have been some examples how, again, a lack of awareness about the nuances and complexities in, of the electricity system have resulted in guidance and advice that is potentially not correct.

So there's a, for example, there's a difference between the carbon intensity of electricity, uh, that is, the average carbon intensity over the course of the day as it changes with the change of the mix of electricity and the marginal electricity intensity in the sense of, if I bring additional load onto the network or if I take load off, then the effect of the generation of electricity

Chris Adams: Is it going to be particularly dirty? Okay, I think you're referring to the fact that you have different companies who have different ways of talking about this. Watttime is one example, they have a marginal intensity and there's maybe other ways which use average intensity. And as far as I understand it, these end up with different incentives.

If you're going to follow the marginal approach, and it's a lunchtime, where there's loads of solar coming in, for example, you might have a very high marginal intensity, thinking that there's lots of power on the grid, so therefore me doing that, the marginal unit of generation might be gas, which is very bad, but that gives you the idea that you shouldn't charge your car when the sun is in the sky, you should wait till it's in the evening instead, when there isn't so much demand on the grid.

It gives you different conflicting signals. This is what you're talking about here,

Daniel Schien: That's exactly what I'm, that's the knowledge of when is it better for me to consume? Or rather, how can I use a carbon intensity for electricity to actually make decisions that are really resulting in fewer carbon emissions being released into the atmosphere? That is the question. And, and the, and, and ultimately we use the term marginal to refer to the, the, the, the relative, uh, change of the intensity as a result of my action.

That's how we want to use the term marginal, but the metrics that are behind some of the released marginal factors, they don't actually represent exactly this goal. Yeah. And so, so this is, that needs to be better understood. We can't use the average variable and interpret this as the marginal, but I'm, this is, for example, one of the, one of the questions on my, in my mind that that needs to be better understood.

And there's a lot of, there's a lot of people from a variety of disciplines that are now looking into this. And it is related to, to this question of causally, how can we, what's going on in the wider system? How do my actions now translate into a change of the system in the future?

Chris Adams: I see. So you're talking, this is one about the time scale that you might have. So on a very short term, this might make sense, but in a longer term, it may be that, let's say we had this example of don't use being in center with a number telling you not to do something when there's loads of sun in the sky.

It may be that in the long run, it makes more sense to actually have a signal for demand so that people just build loads, loads more solar there. But that's not going to be something that's going to be captured inside your kind of short term marginal thing. That's a longer term signal that you'd need to be thinking about, that you'd need to somehow capture in, in a number or an index or something like that.

Right?

Daniel Schien: Exactly. And we've got similar effects for other parts of this networked system that we're working with that provides those services. So the electricity, the electric grid is a network, but our.

Chris Adams: network is a network! Yeah.

Daniel Schien: is a network. And, and so you've got, you've got similar, um, similar problems. Um, maybe the answers will, will look slightly different, um, in each case, but they all need to be looked at, um, collectively, uh, in order to, to, to make decisions.

Chris Adams: Okay, so this idea of the timescale where you might see an impact, as I understand it, this is some of your future research that I think you mentioned to me that you might be looking to do going forward. Is there a chance maybe you might touch on a little bit about that? Because as we just round off the hour, I feel like it might be worth asking you, like, where you feel some of the more kind of promising and really interesting areas of research are. Based on what you've said so far, it sounds like there's probably, I've got a good idea, but maybe you might just talk a little bit about where you expect some of this research to go, because, oh yeah, congratulations.

I saw a chunky grant landed for this kind of research, and I'm very excited to see where it goes now.

Daniel Schien: Yeah, thank you very much. Indeed, I've been, um, very pleased to have been awarded a research grant, um, to investigate the, um, a change-based perspective to the environmental impact assessment for digital services. So everything that we said before around the, the complexities in the system that prevent us from, from making easy conclusions, drawing easy conclusions with the existing methods. We want to now work together. We've got a, uh, a really fantastic set of partners that have that primary data to allow us to to understand robustly what is the current impact, and then also evaluate what is the future impact. And together with the engineers working in those organizations, we want to have conversations that, that help us understand what is, what's going on when digital services are being designed and their interaction with the network.

It's the, it's the relationship between the service and the infrastructure and the consumption that we want to untangle. It's this dynamic system and how it changes over time. And that's uncertain to some degree. What is in the future will always be subject to some uncertainty. But unless we, we dare to ask those questions and understand the basic principles, we are leaving this entirely to chance. And that really is a risk to our ambitions to decarbonize um, all parts of this society. Uh, yeah. So very happy, um, that, that, that I've been trusted with, with this piece of work. And here's a call out, um, to, to listeners. Um, if you're interested to work in this space, um, we are, we are looking for researchers to join us.

Um, there will be ads for a job for a senior research associate coming out into the future and Chris might be able to include

Chris Adams: Yeah, we'll be very happy to share links to this, especially if we get to use some of this research ourselves going forward. Because as you say, we've been struggling as a practitioner when I work in this field. It's very hard to figure out, okay, what am I going to do in the short term? And then what are the things I need to do that work on the longer or medium term?

Because I work in an organization which has a 2030 deadline for an entirely fossil free internet, but also we also have like science-based targets, like the science is informed, basically the industry is saying that we need to halve emissions globally by 50%, particularly in the tech sector by 2030. And there are some papers and things being published to give some indication of this.

But as you've described, Daniel, there's a lot more to it than that. And the more we can actually have to influence policy, the better in this way, in this way. Okay, Dan. I've enjoyed diving into the weeds with you like this. I just want to ask, as we round up, if people have found any of this interesting or would like to continue some of this research, where should they go online to find out more about either your work or some of the papers and things that you're describing?

So we'll add the show notes, but is there a particular place you would direct people to?

Daniel Schien: So, maybe a good starting point is our 2019 CHI paper on YouTube, where we carried out an evaluation of a design change to YouTube that can reduce carbon emissions. Now, this is, this has been done purely with publicly available data. YouTube was not part of this. And so this is, there are assumptions in there and some uncertainty, but methodologically it describes quite well the general approach.

It's also important to note that In this, in this model, we are using an allocation-based approach to estimating the energy consumption of the network and the changes. We are, we're transparent around this and the shortcomings of it. So, so it needs to be seen in perspective, but broadly, I think that's a good text to start with.

Chris Adams: Great, okay, thank you for that. All right, Daniel, I just realized that you are also the author of the Low Carbon Kubernetes Scheduler, a piece of work that has influenced a bunch of nerds inside the GSF. We'll have to talk about that another day, about going from Kubernetes to Low Carbonetes. But Daniel, thank you so much for spending the time on this.

I've really enjoyed nerding out with you on this, and I'm pretty sure we're going to have a bunch of really interesting links and papers for anyone who fancies doing some more research from here. So once again, thank you, Daniel. Alright.

Daniel Schien: Thank you so much, Chris.

Chris Adams: Lovely seeing you again, and take care of yourself, have a lovely weekend.

Daniel Schien: Likewise. Thanks a lot. Bye bye.

Chris Adams: Hey everyone, thanks for listening. Just a reminder to follow Environment Variables on Apple Podcasts, Spotify, Google Podcasts, or wherever you get your podcasts.

And please, do leave a rating and review if you like what we're doing, it helps other people discover the show, and of course, we'd love to have more listeners. To find out more about the Green Software Foundation, please visit greensoftware.foundation. That's greensoftware.foundation in any browser.

Thanks again, and see you in the next episode!