numbers, not adjectives — D. J. C. MacKay

Equitable Atmosphere Declaration

Carl Edward Rasmussen, June 30 2025

Effectively addressing climate change probably requires international cooperation. Cooperation necessitates a common foundation for what is considered “fair”. One possible framework for this is given by this declaration:

Equitable Atmosphere Declaration

We, the undersigned, believe that:
 1)  All people must share equal rights and responsibilities to Earth’s atmosphere.

 2)  Failure to explicitly value atmospheric resources leads to overexploitation through accumulation of greenhouse gases; this failure is one of the root causes of climate change.


Therefore, to limit climate change, greenhouse gas emissions should be priced. Reflecting equity, larger than average per capita emitters should pay for using more than their fair share, and lower than average per capita emitters should be paid for using less. Pricing emissions will create economic pressure on everyone to reduce emissions.

Note, that the declaration isn’t proposing national carbon fee and dividend because its scope is global. It doesn’t include details of implementation; one possible option is the Themis Mechanism. See also the commentary below.

Signatories

Click to sign this declaration via email or email seperately to cer54 at cam.ac.uk (your email address won’t be published).

47 signatories by July 7 2025
name role location
Paul Aston horticulturist, artist Cambridge Botanic Garden
Annouchka Bayley Associate Professor, Faculty of Education Cambridge University
Erik Bodin Research Associate Cambridge University
Lucas Bordeaux computer engineer Cambridge, UK
Nigel Bowles Graduate Tutor, Darwin College Cambridge
John Bronskill Research Associate University of Cambridge
Roger Crisp Director Uehiro Oxford Institute
Carl Henrik Ek professor Cambridge University
Ahmad Elabbar Assistant Professor Cambridge University
Hong Ge Senior Researcher University of Cambridge
Janet Gibson College admin University of Cambridge
Marc Girona-Mata father, student Cambridge University
Julia Gschwind Student Cambridge
Søren Hauberg professor Technical University of Denmark
Philipp Hennig father, professor University of Tübingen, Germany
Isobel Henry student University of Strathclyde, Glasgow
José Miguel Hernández Lobato father, professor Cambridge University
Agnes Heydtmann teacher Cambridge, UK
Ezra Heydtmann student University of Strathclyde, Glasgow
Miro Heydtmann student University of Copenhagen
Yongchao Huang lecturer University of Aberdeen
Shrinivasan Keshav Professor of Computer Science University of Cambridge
Tiffany Ki Research Fellow University of Cambridge
Martin Kleppmann Associate Professor University of Cambridge
Hedda Kraker mother, family and school doctor Cambridge, UK
Fredrik Lindsten father, professor Linköping University, Sweden
Campbell Middleton father, professor Cambridge University
Youssef Moawad Research Associate Glasgow
Roderick Murray-Smith professor University of Glasgow
James Nurdin Student University of Glasgow
Aristeidis Panos Research Associate University of Cambridge
Carl Edward Rasmussen father, professor Cambridge University
Harry Roscoe software engineer London
Jonas Scholz PhD student Cambridge
Shoaib Ahmed Siddiqui father, student University of Cambridge
Silja Sormunen PhD student Aalto University
Geoff Stead tech leader, father Cambridge, UK
Christian Steinruecken research associate Cambridge University
Lauritz Thamsen Academic and a dad Glasgow
Orlando Timmerman PhD Researcher Cambridge
Richard E Turner father, professor Cambridge University
Wim Vanderbauwhede professor Glasgow
Max Welling Prof. Mat Uni of Amsterdam, CTO & Co-Founder CuspAI Amsterdam, Netherlands
Mark van der Wilk professor Oxford University
Joseph Wilson PhD student University of Cambridge
Ave Wrigley father, retired CTO Cambridge, UK
Steve Young Emeritus Professor Cambridge, UK

Commentary

The declaration says that all people must have equal rights and responsibilities towards our shared atmosphere, and that these rights and responsibilities should have material consequences.

What does this mean in practice?

Neither the current per capita emissions of greenhouse gases or the historical emissions have been distributed equally, so pricing of emissions will entail payments. Since it will be impractical to administer a system directly dealing with 8000 million people, a good implementation would allow countries to implement interactions between nations (reflecting the cumulative emissions of all their citizens), and national systems to interact directly with citizens (and these national systems would likely differ between countries to reflect different cultures, etc).

Current and future payments would firstly require a mechanism for setting a price, say per ton of CO2e. Countries would then report their per capita emissions, say for a year. The reported value could reasonably be the total CO2e emissions, adjusted for territorial sinks or sources, such as Land Use and Land Use Change and Forestry (LULUCF), divided by the nation’s population. Payments between countries will reflect the average per capita emissions. Larger per capita emitters will pay, smaller per capita emitters will be paid. Individual nations can internally implement payments to and from citizens in any way they wish.

Historic payments would seem reasonable since the wealth of many developed nations have relied on widespread use of fossil fuels, options which are no-longer available to developing nations, if we are to curb greenhouse gas emissions.

Although the issues of future and historic emissions are related, it may be pragmatic to seek solutions separately. That’s because we urgently need to reduce emissions, and a forward looking agreement may be less difficult to establish, than a historical one. Of course, this should be with the understanding that joining a forward agreement doesn’t absolve big historical emitters from their responsibilities. It’s in all nation’s favour to reach a forward looking agreement, also the less developed. Insisting on coupling the two, may result in no deals at all. We shouldn’t let the perfect be the enemy of the good.

Alternatives: the CBDR-RC

A prominent example of an alternative to the Equitable Atmosphere Declaration (EAD) is the Common But Differentiated Responsibilities and Respective Capabilities (CBDR-RC), adopted by the United Nations Framework Convention on Climate Change (UNFCCC) in 1992 in article 3.1:

The Parties should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof.

Interestingly, the EAD and CBDR-RC are almost opposites: EAD says that rights and responsibilities are equal, whereas the CBDR-RC says they are different. Although the CBDR-RC may sound reasonable on a first reading, the problem is that it is very hard to operationalise, because you need to agree what exactly the different responsibilities and capabilities really mean; a negotiation fraught with difficulties and potentially intractable. On the contrary, the EAD is clear, that rights and responsibilities are equal.