Internet-Draft E-Impact Workshop Report September 2023
Arkko, et al. Expires 23 March 2024 [Page]
Workgroup:
IAB
Internet-Draft:
draft-arkko-iab-ws-environmental-impacts-report-02
Published:
Intended Status:
Informational
Expires:
Authors:
J. Arkko
Ericsson
C. S. Perkins
University of Glasgow
S. Krishnan
Cisco

Report from the IAB Workshop on Environmental Impact of Internet Applications and Systems, 2022

Abstract

Internet communications and applications have both environmental costs and benefits. The IAB ran an online workshop in December 2022 on exploring and understanding these impacts.

The role of the workshop was to discuss the impacts, discuss the evolving needs from industry, and to identify areas for improvements and future work. A key goal of the workshop was to call further attention to the topic and to bring together a diverse stakeholder community to discuss these issues.

This report summarises the workshop inputs and discussions.

About This Document

This note is to be removed before publishing as an RFC.

Status information for this document may be found at https://datatracker.ietf.org/doc/draft-arkko-iab-ws-environmental-impacts-report/.

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This Internet-Draft will expire on 23 March 2024.

Table of Contents

1. Introduction

The IAB ran an online workshop in December 2022 on exploring and understanding the environmental impacts of the Internet.

The background for the workshop was that Internet communications and applications have both environmental costs and benefits. In the positive direction, they can reduce the environmental impact of our society, for instance, by allowing virtual interaction to replace physical travel. Of course, the Internet can equally well act as an enabler for increasing physical goods consumption, for instance, through easing commerce.

Beyond the effects associated with its use, Internet applications do not come for free either. The Internet runs on systems that require energy and raw materials to manufacture and operate. While the environmental benefits of the Internet may certainly outweigh this use of resources in many cases, it is incumbent on the Internet industry to ensure that this use of resources is minimized and optimized. In many cases, this is already an economic necessity due to operational costs. And because many consumers, businesses, and civil societies care deeply about the environmental impact of the services and technologies they use, there is also a clear demand for providing Internet services with minimal environmental impact.

The role of the workshop was to discuss the Internet's environmental impact, discuss the evolving needs from industry, and to identify areas for improvements and future work. A key goal of the workshop was to call further attention to the topic and to bring together a diverse stakeholder community to discuss these issues. This report summarises the workshop inputs and discussions.

The workshop drew many position paper submissions. Of these, 26 were accepted and published to stimulate discussion. There were active discussions both in the meeting and on the workshop mailing list with altogether 73 participants.

Perhaps the main overriding observation is how much there is interest and urgency on this topic, among engineers, researchers, and businesses.

The workshop discussions and conclusions are covered in Section 3. The position papers, and links to recordings of workshop sessions, can be found at https://www.iab.org/activities/workshops/e-impact/. Presentations held during the discussions can be found from the IETF Datatracker at https://datatracker.ietf.org/group/eimpactws/meetings/.

The discussion at the IETF will continue after the workshop, both around specific proposals as well as general discussion on a new mailing list, the e-impact list ([email protected]). You can subscribe to this list at https://www.ietf.org/mailman/listinfo/e-impact.

Some improvements addressing specific situations are being discussed at the IETF, such as the Time Variant Routing (TVR) proposal that can help optimize connectivity with systems that are periodically on or reachable (such as satellites). We expect more proposals in the future.

2. Scope

Environmental impact assessment and improvements are broad topics, ranging from technical questions to economics, business decisions, and policies.

The technical, standards, and research communities can help ensure that we have a sufficient understanding of the environmental impact of the Internet and its applications. They can also help to design the right tools to continue to build and improve all aspects of the Internet, such as addressing new functional needs, easing of operations, improving performance and/or efficiency, or reducing environmental impacts in other ways.

The workshop was expected to discuss:

We expected that the workshop discussions connect analysis of the issues (e.g., scale of energy consumption or carbon footprint) to industry needs (e.g., deployment opportunities) and solutions.

Business and societal policy questions were in scope only insofar as they informed the workshop participants about the context we are in, but what those policies should be was not for the workshop to decide or even extensively discuss. The scope excluded also how the technical community works and meets, such as the question of in-person or hybrid meetings (although it should be noted that the workshop itself was run as an on-line meeting).

2.1. Practical Arrangements

The IAB discussed a potential workshop in this area during its May 2022 retreat. A call for position papers went out in August 2022. Position papers were to be submitted by end of October, a deadline which was later extended by one week.

As noted, the workshop itself was run as an on-line meeting, with four half-day long sessions complemented by email discussions and the position papers submitted by the participants.

All in all, 73 people participated in at least one session in the workshop. Participation was by invitation only, based on the position paper submissions.

Every submission was read by at least three members of the program committee, and acceptance decisions were communicated back to the authors. Review comments were provided for authors for information, and some of the papers were revised before the workshop.

The program committee decided that due to interest and differing areas of expertise, all co-authors were to be invited, and most of them did attend. The program committee also invited a handful of additional participants, where they were seen as providing valuable input. Similarly, as is traditional in IAB workshops, the program committee members and members of the IAB and IESG were offered an opportunity to participate even in cases where they did not submit a position paper.

The IETF secretariat and communications staff provided practical support during the process, sending announcements, maintaining the workshop web page with position papers, setting up mailing lists, tracking submissions, helping with blog article submissions, and so on.

3. Workshop Topics and Discussion

The meeting part of the workshop was divided into four sessions:

3.1. The Big Picture

This session was about the big picture and how the Internet influences the rest of the society. We also spoke about the goals of the workshop.

The session began with a discussion about what is overall involved in this topic. We also looked at how the IETF has approached this topic in the past.

The discussions also expressed the urgency of action and the importance of continuous improvement: an incremental change every year is needed for larger savings at the end of the decade. We continued to talk about the need to recognize how climate changes impact different communities in the world, often unfairly. Finally, we focused on the need to be aware of carbon footprint rather than pure energy consumption - carbon intensity of energy sources varies.

The starting observation from this session was that the issue is much bigger than Internet technology alone. The issue influences all parts of society, and even matters such as (in)equality, externalized costs, and justice. Another key observation was that improvements come in many forms; there is no silver bullet. The opportunity to bring together people with different backgrounds helped us see how we approach the topic from different angles - none of them wrong, but also none of the sole angle to focus on either. Only the combined effects of complementary efforts can provide the required level of changes.

Some of the useful tools for approaching the issue included of course technical solutions, but also solidarity, aiming for sufficiency, and awareness. It is important to not stand still waiting for the perfect solution. Renewable energy and carbon awareness were seen as a part of the solution, but not, however, sufficient by themselves.

As an example demonstration of the diversity of angles and improvements relating to environmental issues, the figure below classifies the areas that workshop position papers fell on:

          +---- Actors & organizations
          |                                 +---- Avoidance
          +---- Benefits to other fields    |
          |                                 +---- User behaviour
          +---- Society, awareness, &       |
          |     justice                     +---- Implementation
          |                                 |
Workshop -+- Improvements ------------------+
          |                                 |
          |     Understanding &             |       +---- Dataplane
          +---- Measurements                |       |
                      |                 Protocols --+---- Routing
                      |                             |
                      +---- Energy                  +---- Edge cloud
                      |                             |
                      +---- Carbon                  +---- Mobile
                                                    |
                                                    +---- Metrics
                                                    |
                                                    +---- Other


      Figure 1: Position paper submission topics

Some of the goals for the IETF should include:

  • Connecting the IETF with others. Given that the issue is broad, it is difficult for one standards organisation alone to make a significant impact, or even have the full picture. Working in collaboration with others is necessary. And understanding the situation beyond technology will be needed.
  • Continuous improvement. It is important that the IETF (among others) sets itself on a continuous improvement cycle. No single improvement will change the overall situation sufficiently, but over a longer period of time, even smaller changes every year will result in larger improvements.
  • Finding the right targets for improvements in the Internet. These should perhaps not be solely defined by larger speeds or bigger capacity, but rather increased usefulness to society and declining emissions from the information and communications technology (ICT) sector.
  • Specifying what research needs to be done, i.e., where additional knowledge would allow us to find better improvements. For instance, not enough is known about environmental impacts beyond energy, such as natural resources used for manufacturing, or the use of water. Carbon-awareness and measurements across domains is also poorly understood today. And business model impacts -- such as the role of advertising on Internet's carbon footprint -- deserve more study.

3.2. Understanding the Impacts

The second session focused on what we know and do not know, and how we can measure environmental impacts.

The initial presentation focused on narrowing down the lower and upper limits of the energy use of the Internet and putting some common but erroneous claims into context. There was also discussion regarding the energy consumption of the ICT sector and how it compares to some other selected industries such as aviation.

Dwelling deeper into the energy consumption and the carbon footprint of the ICT sector there was discussion regarding how the impact was split amongst the networks, data centres and user devices (with the user devices appearing to contribute to the largest fraction of the impact). Also, while lot of the energy consumption related studies and discussions have been focused on data centers, some studies suggested that data center energy usage is still a small fraction of energy use as compared to residential and commercial buildings.

There were also further discussions both during the presentations and in the hallway chats regarding the press and media coverage of the potential environment technologies. The overall sense of the participants seemed to be that there was a lot of sensational headlines, but they were not really backed by measurements done by the industry and academia, and were fraught with errors. Some of these media reports were off by quite a bit, sometimes even by an order of magnitude (e.g., confusing MBps vs Mbps in calculations). The potential harm is having widely circulating misinformation was noted; it can hinder realistic efforts to reduce carbon emissions.

In the rest of the session we looked at both additional data collected from the operators as well as factors that - depending on circumstances - may drive energy consumption. These include for instance peak capacity and energy proportionality.

If energy consumption is little affected by offered load, the ratio of peak capacity to typical usage becomes a critical factor in energy consumption. On the other hand, systems with energy proportionality scale their resource and energy consumption more dynamically based on offered load. The lack of energy proportionality in many parts of the network infrastructure was noted, along with the potential gains if it can be improved.

There were also observations that showed that the energy consumption grew as a step function when the peak capacity was reached (even instantaneously) and additional capacity was built up by performing network upgrades to handle these new peaks. This resulted in a overall higher baseline energy consumption even when the average demand did not change that much. Thus, the ability to shift load to reduce peak demand was highlighted as a potential way to delay increases in consumption when energy proportionality is lacking.

3.3. Improvements

The third session was about potential improvements.

As noted earlier, there are many different types of improvements. In the discussion we focused mostly on protocol aspects, and looked at metrics, telemetry, routing, multicast, and data encoding formats.

The initial two presentations focused on metrics and telemetry with the premise that visibility is a very important first step (paraphrasing Peter Drucker's mantra of "You cannot improve what you don't measure"). There was a discussion of the scopes of emissions and it seemed that from a networking vendor perspective, while directly controlled emissions and emissions from purchased energy are easily measurable, emissions from across the entire value chain can be much larger. Thus it seemed important that the networking vendors had to put in effort into helping their customers measure and mitigate their environmental impact as well. The need for standardized metrics was very clear as it helps avoid proprietary, redundant and even contradictory metrics across vendors.

The initial and the near-term focus was related to metrics and techniques related to energy consumption of the networking devices themselves while the longer term focus can go into topics much further removed from the IETF such as packaging, circular design in order to form a more holistic picture. The overall feeling was that the topic of metrics, telemetry, and management are quite specific and could be targets to be worked on in the IETF in the near term.

The next part of the discussion highlighted the need to understand the trade-offs involved in changing forwarding decisions - such as increased jitter and stretch. Jitter is about delay fluctuation between packets in a stream [RFC4689]. Stretch is defined as the difference between the absolute shortest path traffic could take through the network and the path the traffic actually takes [RFC7980]. Impacts on jitter and stretch point to the need for careful design and analysis of improvements from a system perspective, to ensure that the intended effect is indeed reached across the entire system, and is not only a local optimum.

We also talked about the potentially significant impact, provided the network exhibits energy proportionality, of using efficient binary formats instead of textual representations when carrying data in protocols. This is something that can be relatively easily adopted in new protocols as they are developed. Indeed, some recently finished protocols such as HTTP/2 have already chosen to use this technique [RFC7540]. General-purpose binary formats such as Concise Binary Object Representation (CBOR) [RFC8949] are also available for use.

There were also some interesting discussions regarding the use of multicast and whether it would help or hurt on the energy efficiency of communications. There were some studies and simulations that showed the potential gains to be had but they were to be balanced against some of the well known barriers to deployment of multicast. We also heard from a leading Content Delivery Network (CDN) operator regarding their views on multicast and how it relates to media usage and consumption models. The hallway conversations also talked about the potential negative effects of multicast in wireless and constrained networks. Overall the conclusion was that the use of multicast can potentially provide some savings but only in some specific scenarios.

For all improvements, the importance of metrics was frequently highlighted to ensure changes lead to a meaningful reduction in overall system carbon footprint.

3.4. Next Steps

The final fourth session was about conclusions and next steps. This section highlights some of these conclusions.

3.4.1. Overall Strategy

While only a few things are easy, the road ahead for making improvements seems clear: we need to continue to improve our understanding of the environmental impact, and have a continuous cycle of improvements that lead not just to better energy efficiency but to reduced overall carbon emissions. The IETF can play an important part in this process, but of course there are other aspects beyond protocols.

On understanding our environmental impact the first step is better awareness of sustainability issues in general, which helps us understand better where our issues are. The second step is willigness to understand in detail what the causes and relationships are within our issues. What parts, components, or behaviours in the network cause what kinds of impacts? An overall drive in the society to report and improve environmental impacts can be helpful in creating a willingness to get to this information.

On establishing a continuous cycle of improvements, the ability to understand where we are, making improvements, and then seeing the impact of those improvements is of course central. But obviously a key question is what are the potential improvements, and how can we accelerate them? It should be noted that quick, large changes are not likely. But a continuous stream of smaller changes can create a large impact over a longer period of time.

One of the key realizations from this workshop was that the problem to be solved is very large, complex and that there is no single solution that fixes everything. There are some solutions that could help in the near term and others that would only show benefits over longer periods, but they are both necessary.

One further challenge is that due to the size and complexity of the problem, it was very likely that there might be varying opinions on what KPIs need to be measured and improved.

3.4.2. Improvements

In looking at potential improvements, it is essential that any associated tradeoffs can be understood (note that not all improvements do indeed entail a tradeoff).

Importantly, the role of the Internet in improving other areas of society must not be diminished. Understanding the costs and benefits requires taking a holistic view of energy consumption, focussing not just on the carbon footprint of the Internet but of the broader systems in which it is used. For instance, discussion in session three revealed how some changes might impact latency and jitter. Given that these characteristics are an important factor how virtual meetings are perceived by potential participants, it is important that the performance of networks satisfies these participants at a level where there's willingness to use them over other potentially more environmentally harmful methods, such as travel. Focussing solely on the carbon footprint of the Internet, or solely on the carbon footprint of travel, risks missing the bigger picture potential savings.

Note that while virtual meetings are a common example, it is important to consider different use cases, some of which may not be as obvious to us human users as meetings are. Improvements may bring different or even larger impacts in other situations, e.g., Internet connected electronics might benefit from different characteristics than human users, e.g., with regards to support for intermittent connectivity.

The relationships between different system components and the impact of various detailed design choices in networks is not always apparent. A local change in one node may have an impact in other nodes. When considering environmental sustainability, in most cases the overall system impact is what counts more than local impacts. Of course, other factors, such as device battery life and availability of power may result in other preferences, such as optimising for low power usage of end-user devices, even at the cost of increases elsewhere.

In terms of useful tools for building improvements, the following were highlighted in discussions:

  • Masures beyond protocol design, such as implementations or renewable energy use. Not everything is about protocols.
  • Metrics, measurements, and data are very beneficial. Carbon-aware metrics would in particular be very useful. All additional information makes us more aware of what the environmental impacts are, but also enables optimization, AI-based adjustments, or carbon-directed computing and networking tools, and so on.
  • It would be beneficial to be able to provide various systems a more dynamic ability to slow down and sleep. Awareness of energy availability and type would also allow us to employ time and place shifting for reducing carbon impacts.
  • When we design systems, paying attention to the used data formats may pay off significantly, as argued in [Moran].
  • Possibly there’s a new opportunity for deploying multicast as well [Navarre].
  • Designing systems for energy constrained situations may actually make the resulting systems work well in several environments.

3.4.3. Actions

The workshop discussed a number of possible actions. These actions are not about how to take specific technical solutions forward, but rather about how to discuss the topic going forward or what technical areas to focus on:

  • We need to continue the discussion – not all questions are answered. Additional discussion within the IETF will be needed. Continuing to connect the IETF with others in society and other SDOs around this topic is also useful.
  • It is useful to find a role and a scope for IETF work in this area. The IETF will not develop alternative energy sources, work on social issues or have detailed discussions about implementation strategies or electronics design. However, the IETF has a role in measurement mechanisms, protocol design and standards -- but of course activities in this role need to be aware of other aspects, such as implementation strategies.
  • Increase our understanding of the environmental impacts of Internet technologies. One discussion topic during the workshop was also whether each new RFC should dedicate a section to discuss the these impacts. No conclusion was drawn about the way to document these in RFCs, but it is clear that the IETF community will need to understand the environmental issues better. (Perhaps in addition to learning about the actual issues, guidelines for analysing protocols with regards to their impacts could be useful.)
  • IETF activities on specific technologies are already ongoing or starting, such as metrics discussed, for instance, at the NMRG research group [NMRG] or the OPSAWG working group [OPSAWG], or the new Time Variant Routing (TVR) working group [TVR]. It may be also useful to start from picking the low-hanging fruits, such as:

    • Focusing on improving energy proportionality and the consequent use of efficient data formats.
    • Avoiding crypto assets - such as Non-Fungible Tokens (NFTs) and cryptocurrencies.
    • Being able to carry information that needs to be shared for the purposes of enabling load and time shifting.
  • Help initiate research activities that address some of the issues, such as broader gathering and sharing of measurement data, analysis of this data and looking at business related issues such as the impact of peering or advertising impacts sustainability. In addition, there may be a need to look at research for specific areas of improvements that are promising but not ready for standards discussion.

In summary, the goals that the IETF should have include:

  • Full understanding of the Internet’s environmental impact.
  • Continuous improvement of our technology.
  • Launching research relevant activities.

4. Feedback

The organizers received generally positive feedback about the workshop.

One practical issue from the organizer's point of view was that due to the extension of the deadline, the final submissions and paper reviews collided in part with the IETF-115 meeting. This led to it being very difficult for the program committee and practical organization staff to find time for the activity. We recommend avoiding such collisions in the future.

5. Security Considerations

The workshop itself did not address specific security topics. Of course, individual changes in Internet technology or operations that influence environmental impacts may also influence security aspects. These need to be looked at for every proposed change.

Such influence on security may come in different forms. For instance:

6. IANA Considerations

This document has no IANA actions.

7. Position Papers

The following position papers were submitted to the workshop:

8. Program Committee

The program committee members were:

9. Workshop Participants

The participants who attended at least one of the four sessions were:

10. Informative References

[Adams]
Adams, C., Salsano, S., and H. ElBakoury, "Extending IPv6 to support Carbon Aware Networking", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Anderson]
Anderson, P., Krishnan, S., Lindblad, J., Mitrovic, S., Palmero, M., Roure, E., and G. Salgueiro, "Sustainability Telemetry", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Arkko]
Arkko, J., Lövehagen, N., and P. Bergmark, "Environmental Impacts of the Internet: Scope, Improvements, and Challenges", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Bolla]
Bolla, R., Bruschi, R., Davoli, F., Lombardo, C., and Beatrice Siccardi, "6Green: Green Technologies for 5/6G Service- Based Architectures", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[ClemmA]
Clemm, A., Dong, L., Mirsky, G., Ciavaglia, L., Tantsura, J., and M. Odini, "Green Networking Metrics", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[ClemmB]
Clemm, A., Westphal, C., Tantsura, J., Ciavaglia, L., Odini, M., and M. Welzl, "Challenges and Opportunities in Green Networking", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Eckert]
Eckert, T., Boucadair, M., Thubert, P., and J. Tantsura, "IETF and Energy – An Overview", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[GOS]
Greening of Streaming, "Tune In. Turn On. Cut Back. Finding the optimal streaming 'default' mode to increase energy efficiency, shift consumer expectations, and safeguard choice", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Jacob]
Jacob, R., "Towards a power-proportional Internet", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Jansen]
Jansen, F. and M. Richman, "Environment, internet infrastructure, and digital rights", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[King]
King, M., Krishnan, S., Pignataro, C., Thubert, P., and E. Voit, "On Principles for a Sustainability Stack", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Kostentinos]
Tesfatsion, S., Cai, X., and A. Ahmed, "End-to-end Energy Efficiency at Service-level in Edge Cloud", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Krishnan]
Krishnan, S. and C. Pignataro, "Sustainability considerations for networking equipment", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Manner]
Manner, J., "Sustainability Considerations", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Manojlovic]
Manojlovic, V., "Internet Infrastructure and Climate Justice", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Mattera]
Mattera, M., "Understanding the Full Emissions Impact from Internet Traffic", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Mattsson]
Mattsson, J. P., "Environmental Impact of Crypto-Assets", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[McDaniel]
McDaniel, P., "Sustainability is a Security Problem", ACM Conference on Computer and Communications Security (CCS) , .
[Moran]
Moran, B., Birkholz, H., and C. Bormann, "CBOR is Greener than JSON", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
Navarre, L., Michel, F., and O. Bonaventure, "It is time to reconsider multicast", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[NMRG]
IRTF, "Network Management Research Group (NMRG)", IRTF Research Group, see https://irtf.org/nmrg , .
[Nordman]
Nordman, B., "Applying Internet Architecture to Energy Systems", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[OPSAWG]
IETF, "Operations and Management Area Working Group (OPSAWG)", IETF Working Group, see https://datatracker.ietf.org/wg/opsawg/about/ , .
[Retana]
Retana, A., White, R., and M. Paul, "A Framework and Requirements for Energy Aware Control Planes", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[RFC4689]
Poretsky, S., Perser, J., Erramilli, S., and S. Khurana, "Terminology for Benchmarking Network-layer Traffic Control Mechanisms", RFC 4689, DOI 10.17487/RFC4689, , <https://www.rfc-editor.org/rfc/rfc4689>.
[RFC7540]
Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext Transfer Protocol Version 2 (HTTP/2)", RFC 7540, DOI 10.17487/RFC7540, , <https://www.rfc-editor.org/rfc/rfc7540>.
[RFC7980]
Behringer, M., Retana, A., White, R., and G. Huston, "A Framework for Defining Network Complexity", RFC 7980, DOI 10.17487/RFC7980, , <https://www.rfc-editor.org/rfc/rfc7980>.
[RFC8949]
Bormann, C. and P. Hoffman, "Concise Binary Object Representation (CBOR)", STD 94, RFC 8949, DOI 10.17487/RFC8949, , <https://www.rfc-editor.org/rfc/rfc8949>.
[Robinson]
Robinson, S., Hellstern, R., and M. Diaz, "Sea Change: Prioritizing the Environment in Internet Architecture", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Schien]
Schien, D., Shabajee, P., and C. Preist, "Rethinking Allocation in High-Baseload Systems: A Demand-Proportional Network Electricity Intensity Metric", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Schooler]
Schooler, E. M., Taylor, R., Zilberman, N., Soulé, R., Nafus, D., Manohar, R., and U. Cummings, "A Perspective on Carbon-aware Networking", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Thubert]
Thubert, P., "Digital Twin and Automation", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[TVR]
IESG, "Time-Variant Routing (TVR)", IETF Working Group, see https://datatracker.ietf.org/group/tvr/about/ , .
[Vanderbauwhede]
Vanderbauwhede, W., "Frugal Computing", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .
[Welzl]
Welzl, M., Alay, O., Teymoori, P., and S. Islam, "Reducing Green House Gas Emissions With Congestion Control", Position paper in the IAB Workshop on Environmental Impacts of Internet Applications and Systems , .

Appendix A. IAB Members at the Time of Approval

Appendix B. Acknowledgments

Naturally, most of the credit goes to the workshop participants.

The organizers wish to thank Cindy Morgan and Greg Wood for their work on the practical arrangements and communications relating to he workshop. This report was greatly enhanced by the feedback provided on it, thanks to Michael Welzl in particular for his detailed review.

Authors' Addresses

Jari Arkko
Ericsson
Colin Perkins
University of Glasgow
Suresh Krishnan
Cisco