Sustainable Computing Systems
  A Cheat Sheet

Areas

• 📚 Physics
• 🍃 Sustainability
• 🖥️ Computer System Architecture
• 📈 Live Dashboards
• 📋 Modelling
• 📐 Measurement
• ➰ Adapt Systems
• 🧑‍🤝‍🧑 Community

📚 Physics

Common Quantities

• Time
• Energy
• (Electric) Power

Emission Quantities

• Greenhouse Emissions (e.g. Carbon)
  • ppm (Density)
  • $gCO_2\text{-}eq$: Grams of CO₂-equivalents
    e.g. Methane is 25-fold, i.e. 1g has a higher globabl warming potential
• Various Carbon Intensities $\left[\frac{gCO_2\text{-}eq}{kWh}\right]$:
  • Energy Forms Median (Source):
    • 🌊 Hydro Storage: 7.4
    • ☢️ Nuclear: 13^{*
      *}note the carbon-unrelated issues of nuclear power
    • 💨 Wind: 14
    • ☀️ Solar: 43
    • ⛽ Gas: 486
    • 🛢️ Oil: 840
    • 🪨 Coal: 980
  • Country Grid's Yearly Averages (approx. 2024):
    • Europe:
      • 🇩🇪 DE: 300
      • 🇫🇷 FR: 20
      • 🇵🇱 PO: 750
      • 🇬🇧 UK: 220
    • Africa:
      • 🇳🇬 NG: 360
      • 🇿🇦 ZA: 709
    • America:
      • 🇧🇷 BR North-East: 45
      • 🇺🇸 US Pacificorp East: 650
    • Asia:
      • 🇮🇳 IN East: 787
      • 🇱🇰 LK: 335
    • Oceania:
      • 🇲🇾 MY: 650
      • 🇳🇿 NZ: 48
• CO2 Converter: $1tCO_2\text{-}eq \approx$
  • 🌲 Tree CO2 Absorption: $1.1m^3$
  • 💶 Euros in European Emission Trading System: $70.7€$
  • 🚗 Driving in Car: $7148km$
  • ✈️ Round-Trip European Flights to Munich: $1.7$
  • ⛽ Gasoline: $495l$
  • 🥛 Milk: $714l$
  • 🐄 Beef Steaks: $456 \cdot 150g$

🍃 Sustainability

• "There is no Planet B" (Evidence)

Terms & Definitions

• Sustainability
• Global Warming Potential (GWP)
• Greenhouse Gas (GHG)

Challenges

• Climate Change (#ShowYourStripes): CO₂-focussed
  • Global per capita budget per year: $2tCO_2\text{-}eq$
    for achieving the Paris Agreement 2 Degree Target
  • According to various studies (as of 2024) ICT is said to account for:
    4% of global emissions
  • Hence, everyone spends 80kg on ICT per year.
  • Statista gives the estimated current CO2 emissions per capity and country.
  • In a world on fire, stop burning things.
• Resource Scarcity / Overspending (Earth Overshoot Day: #MoveTheDate)
  • by Country
• Biodiversity
  • Computing does not directly threaten biodiversity.
  • However, computing as decision-making can indeed cause (deliberate) harm.

Political / Historical Events

• 2015: Paris Agreement
• 1972: Club of Rome Report "The Limits to Growth"

Science

• 1980-2020: Chlorofluorocarbon (CFC) as a preliminary success story
  but 60years CFC in atmosphere vs. 1000years for CO2
• 1865: Jevons' Paradox
• 1824: Greenhouse Effect discovered by Fourier^{*
  *} yes, the series/analysis/transform guy

Computing as a Threat to the Environment

• Hardware
  • Dirty production energy
  • Pollution
• Software
  • Planned Obsolescence
• Users
  • Hoarders

Solutions

• The Seven R's (7Rs)
  • Rethink what you use. Are products/services essential? Can they be replaced?
  • Refuse what you do not need. Are there offerings you can simply not take? Are there services/products you receive unsolicitedly?
  • Reduce your usage of products and services.
  • Reuse a product for a different purpose, if you no longer need it or it can not longer fulfill its original purpose. How can you give a 2nd life to a product?
  • Repair what is broken.
  • Recycle to regain materials for manufacturing a new product.
  • Rot products, and thereby give them back to nature.
  • Burn or put into landfill if none of these work.

🖥️ Computer System Architecture

• Hardware
  • Power Supply (Sec. II.A)
  • Batteries (Sec. II.B)
• Software
  • Operating Systems (e.g. Linux, MacOS, Windows, Android)
  • Application Runtimes (e.g. none (aka native), Java Virtual Machine (JVM), ...)
  • Compilers
  • Programming Languages (C, C++, Rust, Java, Python, ...)
    • Pereira et. al (2021): "Ranking programming languages by energy efficiency"

📈 Live Dashboards

• Global
  • Electricity Maps
• National
  • Energie Deutschland (ZEIT)

📋 Modelling

General Carbon & Energy

• SCI
  • $SCI = \frac{O+M}{R}$
• PUE

Low-Earth Orbit

• Low-Earth Orbit Satellites' Carbon Footprint

📐 Measurement

• HW: Power Meters
• SW: hyperfine, carbonperf

➰ Adapt Systems

Hardware

• TODO

Software

• Delivery
• Web

Delivery

Docker Container Frugality

• Python Containers:
  • approx. 650m downloads / year
    measured July 2024
  • overall size of smallest container (alpine): $20MB$
• General Download Emissions
  • approx. $0.06\frac{kWh}{GB}$ (Source)
  • with German average intensity:
    $300 \frac{gCO2eq}{kWh} \cdot 0.06 \frac{kWh}{GB} = 18 \frac{gCO2eq}{GB}$
• Container Footprint:
  • if we were to reduce the container size by 1MB:
    • per 1MB download save: 18 mgCO2eq
    • all yearly downloads: $650m \cdot 18 mgCO2eq = 11.7tCO2eq$
      almost 6 yearly 2 Degree emission budgets

🧑‍🤝‍🧑 Community

Academia

Conferences & Workshops

• ACM SIGENERGY
  • e-Energy: Conference on Future and Sustainable Energy Systems
  • HotCarbon: Sustainable Computer Systems Workshop
• FORC: Foundations of Responsible Computing
• GreenCom: Conference on Green Computing and Communications
• GREENS Workshop: International Workshop on Green and Sustainable Software
• ICT4S: ICT for Sustainability
• IGSC: International Conference on Green and Sustainable Computing
• LIMITS: Workshop on Computing within Limits
• LOCO: International Workshop on Low Carbon Computing
• SUITS: Symposium on Sustainable IT Systems
• WCST: World Congress on Sustainable Technologies

Education

lectures, seminars, projects as part of higher education

• Aspects of Sustainable Compter Systems (Saarland University)
• Sustainable Software Engineering (TU Delft)

Groups

• Green Algorithms

Journals

• ACM Journal on Computing and Sustainable Societies

Industry

• Green Software Foundation

Conferences and Workshops

• GreenIO: For Responsible Technologists
• Ecocompute
• Linux Conferences Sustainability Tracks

NGOs

• Scientists4Future