]> CDT

mknodel@cdt.org

Green Web Foundation

chris@greenweb.org

Green Web Foundation

michelle@thegreenwebfoundation.org

Sustainability and the Internet (SUSTAIN) RG e-impact sustain The global internet is comprised of vast interconnected networks spanning nearly every surface of planet and sky that, together with user devices, consumes energy and emits greenhouse gases. The true scale and proposed mitigations of the carbon footprint of the internet are the subject of important research. The internet also requires the depletion of other natural resources beyond carbon, namely land, water, electromagnetic spectrum and minerals. Electronic waste contributes in particularly acute ways to environmental pollution. This document surveys the impacts of the internet on the environment and includes, but goes beyond, energy use and carbon footprint to look at the consumption of natural resources and environmental waste. About This Document Status information for this document may be found at . Discussion of this document takes place on the SUSTAIN Research Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at .

Introduction The internet is the biggest machine we've ever created, extending from the depths of the ocean all the way to low earth orbit. Much research has been invested in understanding environmental impacts. Research such as the ‘United Nations (UN) Digital Economy Report: Shaping an environmentally sustainable and inclusive digital future’ examines the true scale and proposed mitigations of the carbon footprint of the internet . Related research by the World Health Organisation primer on the health impacts of e-Waste details the harms incurred when the majority of e-waste is processed . Standardized methodologies also exist for conducting these assessments, such as Recommendation L.1410 from the International Telecommunication Union's Telecommunication Standardization Sector (ITU-T) for life cycle assessments of information and communication technology (ICT) goods, networks, and services . This document originated in discussions at the 2022 Internet Architecture Board (IAB) Workshop on Environmental Impact of Internet Applications and Systems [RFC9547]. This document aims to briefly categorize a complete survey of environmental impacts due to a global internet operating at scale. It is the expectation that these impacts are persistent and some will have few to no mitigations, even given a very long arc of innovation and scientific advancement. That is because each of these impacts are intimately tied to the physical limits of our planet, which are far more finite than our imaginations are capacious . It is, however, of utmost importance to confront and understand the planet's limitations and the ways in which internet growth pushes up against them. A 'climate justice' approach to building internet architecture not only reduces the internet’s own environmental impact but reduces overall environmental impacts of our society. Environmental, Social, and Governance (ESG) frameworks are a related but distinct lens through which the impacts of internet infrastructure are increasingly assessed. In practice, however, ESG analysis of the technology sector tends to reduce to a tension between mining, for the battery and mineral inputs of the energy transition, and energy, from nonrenewable sources -- a reductionist frame relative to the fuller set of impacts surveyed in this document . Nonetheless, addressing these impacts is also increasingly a business imperative: customers increasingly demand it, and regulation increasingly requires it, as with the EU's Corporate Sustainability Reporting Directive and Energy Efficiency Directive . This document summarizes the most promising mitigations in the context of internet networking. We further suggest a principled approach to guide understanding the problem space and taking measurable action. Our proposed approach aims for technical excellence, is informed by prior implementation and testing, documents clearly and concisely; and is open and fair in its assessments.

The Internet's Environmental Impacts This section is arranged in three sub-sections: 2.1. Carbon, 2.2. Natural Resources and 2.3. Waste. In the first section, of course carbon is a natural resource but in this document we rely on the vast research and documentation elsewhere to discuss the consumption of energy and its emissions in the form of greenhouse gas. Land, water, electromagnetic spectrum and minerals are all finite, non-renewable resources that are consumed by internet infrastructure and these impacts are explained in depth with citations. Lastly waste is discussed as its own very consequential impact on the pollution of the rest of the environment, living and nonliving.

Carbon Carbon footprint is a concept that takes into consideration emissions and global warming and the ozone layer. The projected impacts, and mitigations of global warming are extensively detailed in the Intergovernmental Panel on Climate Change’s sixth assessment . Progress on allowing the ozone layer to recover since the 1980s is at risk of being undone as a result of the deployment of low-earth orbit constellation satellites . A primary driver of the carbon emissions of internet infrastructure stems from the energy sources powering it. Not only is it often powered by non-renewable energy sources , but the amount of energy used is increasing faster than efficiency gains can offset . In addition, the chip and semiconductor sector has a significant environmental footprint , as do other emerging digital technologies, notably artificial intelligence (AI) . The packaging and global transport of network equipment and end user devices is a further, often overlooked, source of carbon emissions. Energy consumption is the unequal distribution of and limitations on use of carbon energy for various purposes. The share of global carbon emissions is unevenly distributed across countries, but also within countries across income levels .

Natural resources Natural resources such as land, water, minerals and electromagnetic spectrum are all impacted by increased digitalisation and the growth of the internet. The Earth-system-science framework defines nine "planetary boundaries": climate change, novel entities (such as chemical pollution and plastics), stratospheric ozone depletion, atmospheric aerosol loading, ocean acidification, biogeochemical flows of nitrogen and phosphorus, freshwater use, land-system change, and biosphere integrity. Six of these -- climate change, novel entities, biogeochemical flows, freshwater use, land-system change, and biosphere integrity -- have already been transgressed, suggesting that Earth is now well outside of the safe operating space for humanity . These resources raise two distinct kinds of scarcity. Some are finite in total quantity because they are non-renewable, raising the question of whether there is enough to go around at all. Others raise a related but orthogonal issue of capacity, which is space-time dependent: whether there is enough to go around at a specific place and time, a question of equitable distribution and usage rather than total abundance.

Land Internet infrastructure now occupies every physical domain: space, including deep space; the ground beneath our feet; and the sea, down to the sea bed. New work is beginning at the IETF to define an IP protocol stack for deep space communications, extending internet infrastructure beyond Earth orbit entirely [I-D.many-deepspace-ip-architecture]. On the ground, internet infrastructure is often strategically placed geographically and geopolitically. While the Earth's crust is finite in total (a background abundance constraint), the more immediate impact is one of capacity: a given site, once occupied by internet infrastructure, cannot simultaneously be used by other humans. Data centers themselves form a distinct land-use ecology, reshaping the geography, water tables, and energy grids of the regions that host them . Two broad approaches to data center governance have emerged. One is centered on market efficiency, intellectual property protection, and continued growth, often citing competitive advantages such as favorable climate or existing infrastructure. The other treats land, water, and energy as scarce resources rather than assuming their abundance, and argues for centring people and planet over profit and capital . Product-level standards, such as the European Union's (EU) ecodesign requirements for servers and data storage products, offer a standards-based lever that could help operationalize this latter approach in law, constraining resource use and waste regardless of ownership model . At sea, undersea internet cables and related infrastructure disrupt the sea bed. Furthermore untouched areas of the deep sea are being proposed for mining instead of reusing minerals already in circulation . In addition, undersea internet cables face growing risk from extreme weather and sea level rise affecting the coastal infrastructure they depend on .

Animals and other ecosystems This scarcity of land also affects animals and other ecosystems. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Global Assessment Report on Biodiversity and Ecosystem Services in 2019 provided a IPCC-like basis for policy and decision making, evaluating 15000 scientific publications, from 145 authors from 40 countries. It found 82% of wild mammal biomass had been lost in the last 50 years, and called for transformative changes to avoid further biodiversity loss. A "handprint" is a concept developed in contrast to footprint, to quantify the positive environmental impact of a technology, product, or organization. Footprint and handprint are calculated independently, with footprint minimized and handprint maximized; a positive handprint should not be treated as compensating for a negative footprint, as doing so risks greenwashing .

Water Water is used extensively throughout the digital technology sector, particularly within data centers for cooling, for mineral extraction and production, and for chip and semiconductor manufacturing . Water is renewable at a global scale, so the primary issue is one of capacity rather than abundance: whether enough is available in a specific place at a specific time. Water use continues to increase, driven primarily by more advanced AI and cloud computing needs, and often places strain on water resources in the communities surrounding data centers, an effect compounded where non-renewable groundwater aquifers -- themselves an abundance-constrained resource -- are drawn down faster than they can recharge. Many data centers, chip fabs, and other digital infrastructure are being built in already water-stressed areas such as Spain and the U.S. state of Arizona. Chip fabrication is particularly water-intensive: Taiwan's semiconductor fabs alone consume tens of thousands of cubic meters of water per day, competing directly with agricultural and municipal supply during droughts . This limits the availability of water for other human, animal, and ecosystem needs at that same place and time .

Electromagnetic spectrum Electromagnetic spectrum is not consumed or depleted by use, and the same frequencies can be reused in different places or at different times. Its scarcity is therefore a matter of capacity rather than abundance: access to specific frequencies at a specific place and time continues to be allocated disproportionately to large companies and wealthier countries, despite ITU commitments to more equitable allocation.

Minerals Minerals are the clearest case of an abundance-constrained resource in this document: once a deposit is extracted and consumed, it cannot be replenished on any human timescale. Mineral extraction depletes finite resources. Extraction requires significant water use. It scars and degrades the Earth's crust. It destroys habitats. Extraction processes are toxic at the point of extraction. This limits the availability of land for other uses. Manufacturing network equipment and end user devices from these minerals carries its own environmental footprint, separate from the impacts of extraction itself. Global mineral extraction, processing, and refining also carries significant human rights impacts, including the use of forced labor for minerals sourced from conflict zones . Despite minerals being finite resources, demand for them continues to grow rapidly as new digital and energy technologies depend on them .

Waste In the air -- pollution from fossil fuels, burning e-waste. On earth -- sanitation, landfills, polluting soil, limiting use of space, ecosystem disruption, as documented at e-waste processing sites such as Agbogbloshie, Ghana . This waste also poisons water: toxic leachate from landfills and informal e-waste processing sites contaminates groundwater and waterways relied on by surrounding communities. In the sea -- undersea cables, mineral extraction byproducts, e-waste shipping, pollution. In space -- debris, crowding the sky scape, congestion, limit of use. Only a small fraction of e-waste is formally collected and recycled: 22.3% globally in 2022, with e-waste generation growing nearly five times faster than documented recycling. Recycling rates also vary sharply by region, from 42.8% in Europe to less than 1% in African countries .

Guiding Principles As the practice of digital sustainability is still in development, we suggest the following principles to guide IETF’s approach to the topic, building on prior proposals for a sustainability stack for Internet architecture . These principles are designed to be more enduring concepts that can inform solutions even as the technical specifics of those solutions evolve with the field.

• Open and fair: Claims about environmental impacts must be publicly verifiable, such as linking to publicly available evidence and allowing third party auditing. Publicly verifiable evidence contributes to higher confidence in the measurements and facilitates independent monitoring and assessment as well as ensures fairer participation and competition, as in mandatory public reporting regimes such as the EU's data center sustainability indicators .
• Timely: Where possible, move towards real-time information about impacts over an annual cadence or slower cadence. More timely data enables more responsiveness and a higher resolution of understanding, as called for in ongoing work on green networking metrics and management [I-D.cx-opsawg-green-metrics] [RFC9845].
• Within planetary boundaries: Treat the carrying capacity of the planet, as determined by the best available science, as a constraint to work within. There is a safe operating capacity of the planet, that when breached represents a critical risk to people and ecosystems we are part of, causing avoidable harm.
• Demand and supply can both be levers: Reducing demand for resources is also a valid and important approach in addition to providing supply more efficiently, including by applying Internet architecture principles to energy systems directly .
• Backwards compatibility: The maintenance of existing protocols and backwards compatibility in protocol design, as opposed to new protocol stacks such as "Green IP", reduces the need to manufacture new networking hardware and end user devices.
• Full-stack integration: Sustainability should be integrated throughout the stack, from software design and refurbished hardware procurement to grid-aware computing and the choice of hosting providers powered by renewable energy.
• Sustainable procurement: Sustainable and rights-respecting procurement practices should be prioritized and embedded throughout an organization.
• Sustainability by design: Sustainability should be embedded from the start of a project or protocol's design, not added as an afterthought.
• Data sharing: Sharing data about resource consumption improves reporting and transparency and helps create measurable benchmarks.

Conclusions Key mitigations include reducing extraction, improving architectural efficiency to reduce cooling needs, and distributing resources more equitably. Data localisation choices also affect environmental impact. Backwards compatibility and protocol maintenance can serve as antidotes to premature hardware obsolescence, sometimes termed "Green IP". The rapid growth of computationally-intensive applications, such as large language models, is a significant new driver of this resource demand .

Security Considerations There are no security considerations for this document.

IANA Considerations This document has no IANA actions.

Informative References United Nations World Health Organization n.d. IPBES Oxfam ITU-T Study Group 5 ITU-T Study Group 5 International Energy Agency Stand.earth Green European Foundation World Bank European Union International Telecommunication Union United Nations Institute for Training and Research European Commission European Union

Acknowledgments The authors would like to thank Michael Oghia and Emile Stephan for their detailed reviews and suggested additions to this document.