Glossary

Acknowledgements

The Climate Equity Reference Calculator is a general equity reference tool, designed to allow the user to specify their own preferred interpretation of national responsibility and capacity for climate action, which in turn is used to determine each country’s fair share of the global climate effort.

The Calculator was developed by Tom Athanasiou & Paul Baer of EcoEquity and Sivan Kartha & Eric Kemp-Benedict of the Stockholm Environment Institute, who also developed a specific effort-sharing approach, the Greenhouse Development Rights framework (which has since been generalized into the Climate Equity Reference framework.  Most of the initial Calculator programming was also done by Eric, with the assistance of Douglas Wang. Tyler Kemp-Benedict did most of the user-interface design and implementation.  More recently, Christian Holz has joined the CERP team, and among much else, has become a key team programmer. The core funding for these effort has been provided by the Stockholm Environment Institute, the Rockefeller Brothers Fund and Christian Aid. 

The core of the Climate Equity Reference framework is still the dynamic Responsibility and Capacity Index approach.  Or, as we sometimes call it, the "Responsibility, Capacity, and Need approach."  However, the CERP approach has been substantively generalized, and much more generalization and extension is planned for the future.  

We would also like to thank Kirk Smith, who as far as we can tell invented the Responsibility and Capacity Index, or at least the approach that it embodies. (We thought that we had done so, but in fact Kirk beat us by over a decade!) See Kirk R. Smith, Joel Swisher, and Dilip R. Ahuja, "Who pays (to solve the problem and how much)?," in Peter Hayes and Kirk Smith (eds.), The global greenhouse regime: Who pays?, United Nations University Press/Earthscan, London, 1993.

Adaptation Need

In these calculations, a country or region’s share of the Global Mitigation Requirement is proportional to its Responsibility and Capacity Index.  The Responsibility and Capacity Index can also quite properly be used to estimate national fair shares in a global adaptation effort.  Not that it can help us to estimate the global adaptation need, or the adaptation need of any given country, but it does offer a way to think about national fair shares of any monetized, global, climate-related effort.  

(Global adaptation need is properly estimated as a function of projected temperature change and national vulnerability.  At the moment, in the Calculator, all we offer is a user-defined parameter that is specified as a percentage of projected Gross World Product.)

Business as Usual

Any effort-sharing framework (as opposed to resource-sharing frameworks that divides up a fixed emissions budget) requires baselines. This is because “effort” must be measured against a baseline, and – by definition – it should be a “no effort” or “no policies” baseline.  

The construction of such baselines is challenging, but plausible projections can be made. 

In this system, we have approached this problem in a straightforward manner.  Our baselines are derived from an existing set of standard sources: UN Population Division, IMF, US EPA, McKinsey and Company. We update and calibrate these to be consistent with the most current available annual emissions data, based on fossil fuel CO2 from numerous other sources.

For a much more detailed discussion, see Definition, sourcing, and updating of the emissions baselines.

Capacity

This calculator defines capacity in income terms. It allows the user use a progressive definition, in that it is possible to define a level of income (a development threshold) below which income does not count toward capacity, similar to the way typical income tax schedules do not tax income below a certain exemption level. In this calculator, national capacity is calculated as the sum of all individual incomes, excluding income below the development threshold.

Capacity is measured in market exchange rate (MER) terms, while the development threshold is expressed in Purchasing power parity (PPP) terms and then converted to country-specific values using the ratio of MER and PPP exchange rates appropriate to each country.

This capacity is combined with responsibility to calculate a Responsibility and Capacity Index, which is taken as a measure overall obligation to act.

Development Threshold

The development threshold defines an income threshold below which an individual's income, whatever country they may reside in, is taken to be exempt from the calculation of national fair shares.  Which is to say that income below the development threshold is not taken to contribute to national capacity, nor are emissions corresponding to consumption below this threshold taken to contribute to national responsibility

This threshold can be set between $0 and $20,000 per person per year (in Purchasing Power Parity terms). For reference, a development threshold of $7,500 PPP per person per year, which is a bit above a reasonably-defined global poverty line based on empirical observations, is the standard setting presented to the user.

Emissions Intensity

Emissions Intensity is a measure of the efficiency of a country’s economic activity, in terms of greenhouse gas emitted per unit of economic output. It is defined as greenhouse-gas emissions divided by Gross Domestic Product, and can be calculated in CO2-only terms or it can include non-CO2 gases.

Equity Settings - what they are and how to use them

The Climate Equity Reference Calculator does not produce one, single, "correct" result.  Rather, it offers a set of controls, and when you click past this page you'll have the opportunity to change them at will.  This Equity Settings page, on the other hand, contains only the key equity parameters, the ones where you specify how ambitious a climate transition you'd like to model, and how you want to interpret the core parameters defining responsibility and capacity.

Choose your preferences. You can always change them later.  

Level of Global Ambition

First, chose a mitigation pathway. You have three options, which are carefully defined to represent three politically distinct storylines. You can read more about them here.

Common but Differentiated Responsibilities and Capacities

The core of the Equity Reference Calculator is the Responsibility and Capacity Index. The controls in the center of the Equity Settings page determine how national RCIs are calculated.

  • If you choose a box from the top row of the matrix (or the first bullet under "Responsibility vs. Capacity, relative weight") you instruct the calculator to consider only responsibility. Similarly, if you select a box from the bottom row, you instruct it to consider only capacity. If you choose a box in the middle row, responsibility and capacity are weighted equally -- a 50/50 weighting. Note that, once you've clicked past this Equity Settings page to the Calculator itself, you can choose any weighting of capacity and responsibility.
  • The columns relate a different aspect of effort-sharing problem -- progressivity
    • If you choose a box from the center column (or the first bullet under "Progressivity, between and within countries") you're selecting the "standard" development threshold. That is, you're instructing the system to exclude all income below $7,500 (PPP) from the calculation of capacity, and all emissions corresponding to consumption below that same threshold from the calculation of responsibility.
    • If you choose a box from the left column, you're instructing the system to use a much lower development threshold, one just a bit higher than the average per-capita income in the Least Developed Countries. That is, you're reducing the overall progressivity of the effort-sharing calculations.
    • If you select a box from the right column, you're choosing settings that are more progressive than those in the central column. The development threshold stays $7,500 (PPP), but you also activate a  luxury threshold that is defaulted to a per-capita income of $100,000 (MER dollars) per person per year, which is just about the point that defines the "global one percent."  In this case, as income rises above the development threshold, a linearly increasing percentage of that income (and the associated emissions) are counted towards national capacity (and responsibility), until, when the luxury threshold is reached, it is all counted toward national capacity. The effect is to shift obligation (if you will) up the global income scale. This is a simple analog to a progressive income tax, with a zero tax bracket up to the Development Threshold, and a maximum tax bracket starting at the Luxury Threshold. Again, note that the Calculator itself provides a wider set of controls.

Historical Responsibility Start Date

Since responsibility is defined as cumulative emissions (arising from consumption above the user-specified development threshold), it is necessary to specify an initial year for accounting for emissions. While the Equity Reference Calculator is not a budget-sharing system, if you select 100% Responsibility and a development threshold of $0, it becomes a effort-sharing system in which national fair shares are entirely proportional to national historical emissions. 

Fair Share

A nation's overall fair share of the global climate effort is calculated as a percentage of that global effort -- whether mitigation or adapation related -- and is based on the country's share of the global responsibility for causing climate change and capacity for addressing it. These are expressed in a Responsibility and Capacity Index, which is calculated based on user's own preferred interpretation of national responsibility and capacity. These preferences are set in the panel to the left labeled Calculator Settings, and a core subset of them are also accessible in the Equity Settings panel. 

Critically, a nation's fair share is not seen in domestic terms, though its mitigation potential of course is. The CERP views climate as a global commons problem that can only be solved within a high-cooperation international regime. Such a regime can only be established if each Party sees others to be doing their fair shares in the face of the common challenge.  In practice, of course, each country will decide, on the basis of its own specific considerations (e.g. it’s own view of costs, co-benefits and political-economic tradeoffs) what fraction of its fair share of the global effort it will attempt domestically, and what fraction it will make off shore” by supporting action in other countries.

Global Mitigation Pathways / Level of Global Ambition

A mitigation pathway is a global emissions trajectory that is designed to, over time, keep the climate system within a given carbon budget, or to keep temperature increases below a certain limit. The more stringent the budgetary or temperature limit, the higher the level of global ambition.

The Climate Equity Reference Calculator supports three mitigation pathways. They range from the Strong 2ºC pathway, which is an emergency mitigation pathway by any definition, to the G8 pathway, which is based on the (politically influential) targets specified in the G8’s 2009 Declaration in the Italian town of L’Aquila.

    • The Strong 2ºC pathway is defined to conform to an extremely challenging carbon budget - the most challenging we could defend as being techno-economically achievable. While we cannot give a quantified estimate of its likelihood of staying below 1.5ºC, we can say that, by comparison with the emission budgets given in the IPCC's Fifth Assessment Report, it has a greater than 66% likelihood of keeping total warming below 2ºC.  In this pathway, global emissions peak in 2014 and annual fossil CO2 reductions reach a maximum rate of 6% annually. Non-CO2 emissions have a “floor” of 5 GtCO2 annually, to account for the potentially irreducible requirements of agriculture.  Importantly, we do not assume net-negative emissions in either the fossil-fuel or land-use sectors.
    • The Weak 2°C pathway is deliberately similar to well-known emissions pathways that have generally been considered to have a “likely” (roughly 67%, in the IPCC’s terminology) chance of maintaining less than 2ºC of warming.  However, such pathways now carry an important caveat – the IPCC's Fifth Assessment Report suggests that these pathways and their associated CO2 budgets carry substantially higher risks of exceeding 2ºC than was previously estimated. In any case, this pathway, like our Strong 2ºC pathway, peaks immediately (2014); its rate of decline then increases gradually, reaching a maximum of 4.4% in 2050.  Like the Climate Action Tracker's 2ºC pathway, its emissions in 2020 are 44 GtCO2equivalent.
    • The G8 pathway, for its part, is not calibrated to a specific temperature threshold, but is based on the politically influential targets specified in the G8’s 2009 Declaration in the Italian town of L’Aquila.  The L’Aquila text specifies only that the peak must be “as soon as possible” and omits the reference year against which goal the 50% global reductions by 2050 is to be calculated. In our rendering, its peak year is 2020, and the maximum annual rate of post-peak emissions decline is 6.0%. (The late peak requires very rapid reductions in order to reach its 50% in 2050 specification, and this despite its relatively larger budget.)  The pathway's 2012 to 2100 CO2 budget is ~1600 GtCO2, which is well above the largest of the IPCC's budgets, the one that is given a 33% chance of staying below 2ºC.  One can safely say that it is “very likely” to exceed 2ºC by 2100. 

For much more information on all of this, including a comparison of these pathways to the IPCC's emissions budgets, see the Mitigation Pathway Overview.

Global Mitigation Requirement

The global mitigation requirement is the “mitigation gap” between emissions under a global Business-as-Usual pathway and emissions under the specified global mitigation pathway. In any given year, for any given BAU and mitigation pathway pair, this gap can be expressed as a number of Gigatonnes of CO2 or CO2equivalent. This is the number of tons to be mitigated in that year. This global mitigation requirement can be allocated to individual countries, in proportion to their Responsibility and Capacity Index, to determine their fair share of the global mitigation effort.

Greenhouse Development Rights (GDRs)

Greenhouse Development Rights was a ground-breaking equity reference framework based upon national responsibility and capacity for climate action, and national (development and adaptation) need.  It has been generalized into and superceded by the Climate Equity Reference framework.  The core of the Climate Equity Reference framework is still the dynamic Responsibility and Capacity Index approach.  However, the CERP approach has been substantively generalized, and much more generalization and extension is planned for the future.  

Historical Responsibility Start Date

Here the user specifies the initial year in the calculation of cumulative emissions for the purposes of assessing a country's Responsibility, which is defined as cumulative emissions (arising from consumption above the user-specified development threshold).

Intro to Climate Equity Pledge Scorecard

The Climate Equity Pledge Scorecard is is intended as an easy-to-use tool to compare countries’ “pledges” – their promises of mitigation action – to their fair share of the global effort. The Scorecard is a general equity reference tool designed to allow users to specify their own preferred interpretation of national responsibility and capacity for climate action, which in turn is used to determine each country’s fair share of the global climate effort.

In principle, the Scorecard views national fair shares as the sum of domestic mitigation and financial support for international mitigation. Unfortunately, explicit pledges tend to be announced only for domestic mitigation alone, and not for financial support for international mitigation. Some wealthy (high capacity) countries do provide some support for international action of various kinds, but generally not in a manner that is explicitly reported and accounted in a coherent manner.

Because of this lack of explicit and credible information, the Scorecard does not include the financial support for international mitigation in the assessment of a country's pledge. If accountable financial pledges are ultimately made, these will be included, and many scores will improve.

Note that pledges score better when evaluated against the G8 marker pathway than they do when scored against the Stong 2°C pathway. Unfortunately, the G8 marker pathway provides only a poor chance of keeping warming below 2°C. (See the Mitigation Pathway Overview for details).

Kyoto Obligation

The Kyoto Protocol is an agreement under which the world’s industrialized countries commited to limits on greenhouse gas emissions. Some countries complied with the Kyoto protocol emission limits, but some did not ratify, and some withdrew from the agreement. Views differ on how this should affect fair shares going forward, and thus, the Equity Reference Calculator allows the user to select whether "Kyoto obligations" are to be included or excluded when calculating national fair shares and evaluating national pledges.

If they are included,  then countries like Canada which not met their Kyoto target must reduce their emissions from their actual level in 2012 to their Kyoto target before any further reductions are counted towards their global (Responsibility and Capacity Index-based) fair shares. The effect is that Kyoto non-compliers have fair shares going forward that are larger by an amount equal to the amount by which they exceeded their targets. All other countries have somewhat smaller fair shares, because the shared global climate-related need (which is divided among countries on the basis of responsibility and capacity) becomes smaller by an amount equal to the aggregate amount by which Kyoto non-compliers exceed their Kyoto targets. 

There are three different ways in which Kyoto obligations can be treated.

  • They can be included for all countries. Thus, the US and Canada are treated as if they were still parties to the Kyoto protocol.  This allows the calculator to take account of the moral, if not legal, obligations that were implied by the original signature (the US) or ratification (Canada) of the Kyoto Protocol. More generally, it highlights the significance of non-compliance as a form a “free riding” – an issue that goes far beyond Kyoto. 
  • They can be excluded for all countries, which means that Kyoto non-compliance is ignored.  The Kyoto Protocol thus has no bearing on future fair share.  This option, importantly, is the default. 
  • They can be included for all countries except the US and Canada, which are not or are no longer parties to the Kyoto protocol, regardless of their previous intent to comply.  

Mitigation cost as % of GWP

Estimates of the cost of a mitigation vary widely, and depend on a wide range of assumptions. The Equity Reference Calculator does not assume a particular cost, but rather permits the user to specify an estimate of the cost.  The cost specified by the user is an annual cost, as a % of GWP, that is assumed for simplicity to be constant over the entire time period. The specified cost also determines a global average (not marginal) per-ton carbon-dioxide mitigation cost.

This hypothetical cost estimate -- added to the adaptation cost estimate -- is used (in the Country Report and the "Fair share" table view) to estimate fair shares (national and per capita) of total costs.  (The specified cost is not used in calculating fair shares of the mitigation effort, which are expressed in terms of tons.)

 

Mitigation Fair Share

A country's mitigation fair share is its fair share of the global mitigation requirement.  It is proportional to both the stringency of the mitigation pathway and the country's Responsibility and Capacity Index

A developed country, with relatively large fractions of total global responsibility and capacity, typically has a mitigation fair share that is larger than it’s domestic mitigation potential.  That is, a mitigation fair share that is larger than any that it can efficiently discharge within its own borders. 

A developing country, with relatively small fractions of total global responsibility and capacity, typically has a mitigation fair share that is smaller than its domestic mitigation potential.  That is, it contains mitigation potential that must be used in order to realize a high-ambition global transition.  In practice, this means that it must be "matched" with support provided by developed countries that need it in order to discharge their mitigation fair shares. 

More Detailed Calculations

This link takes you to the Climate Equity Reference Calculator, where you can see and experiment with an analysis that is much more detailed than the one available in the Climate Equity Pledge Scorecard system.

Pledged Effort

The Equity Reference Calculator assesses the national pledges that countries have submitted to UNFCCC Secretariat. (The official Annex 1 submissions and non-Annex 1 submissions are available on the UNFCCC website, and helpful compilations are available from the Climate Action Tracker and Climate Interactive websites. We rely upon these roll-ups and do not attempt to collect additional information about pledges. In a few cases, we adjust our pledge database to take account of important, but not yet widely reported, changes in national pledges.

To this point, almost all mitigation pledges are given for the year 2020. Some countries have submitted both an “unconditional” pledge, which they intend to meet unilaterally, and a more ambitious “conditional” pledge, which is contingent on other countries raising their own mitigation ambition and/or providing financial and technological support.

While this Equity Reference Calculator views national fair shares as the sum of domestic mitigation and financial support for international mitigation, only the mitigation pledges can currently be assessed.  This is because explicit pledges tend to be announced only for domestic mitigation alone, and not for financial support for international mitigation (not to mention adaptation). Some wealthy (high capacity) countries do provide some support for international action of various kinds, but they do not generally do so in a manner that is explicitly reported and accounted in a coherent manner.  Because of this lack of explicit and credible information, it is not possible to consider financial support for international mitigation in the assessment of a country's pledge. 

Responsibility

In the calculations here, responsibility – contribution to the climate problem – is defined as the sum of all emissions corresponding to consumption above the user-specified development threshold (as is the case with capacity).  Emissions corresponding to consumption below that threshold are not included in the calculation of responsibility, as they are exempted on the grounds of, say, being associated with basic or survival consumption.

Responsibility is measured cumulatively since some user-specified start date. (To the extent that emissions before the start date contributed to current capacity, they are accounted for implicitly in the capacity measure.) In calculating national fair shares, responsibility and capacity (a simple average, in the default case, though the weighting can be changed) are combined to compute a Responsibility and Capacity Index.

Responsibility and Capacity Index (RCI)

The Responsibility and Capacity Index (RCI) combines measures of responsibility and capacity (using a user-specified weighting) into a combined indicator of national obligation.

The RCI is then used to straightforwardly calculate each country's fair share of the global climate effort --  a country's fair share of the global effort (say, in total tons of mitigation required) is proportional to its RCI.

A country's RCI is affected by its income distribution, because both responsibility and capacity are calculated in terms of a user-specified development threshold. For any non-zero development threshold, the resulting effort-sharing allocation, if interpreted as a climate tax, is mildly progressive. in other words, a dollar of income that is just above the development threshold is “taxed” at the same rate as a dollar earned by a billionaire.

Score

Scores reflect the amount by which a country's pledged reductions fall short of (or, in rare cases, surpass) their fair share of the global mitigation requirement.

On the scorebar, a country’s fair share of 2020 global emissions reductions is shown as the distance from its 2020 business-as-usual (BAU) emissions to the zero point. Its pledge is shown as the distance from its BAU to its score.  

Most country's pledges fall far short of their fair share of the effort.  This leaves a red gap to the left of the zero point, and yields a negative score.

A few country's pledges surpass their fair share of the effort, by an amount shown as a green bar to the right of the zero point, and yields a positive score. 

 

Type of Pledge

Many countries have expressed their national emissions mitigation pledges in the form of an unconditional pledge and a conditional pledge. The unconditional pledge is weaker (lower in ambition), but will be met unilaterally. The conditional pledge is stronger (higher in ambition) but becomes active only if other countries satisfy certain requirements relating to increasing their own ambition with respect to mitigation pledges and/or the provision of finance and technology.

Note that some countries have offered only a single pledge, and sometimes an ambiguous definition of it as well.  In rare cases -- to illustrate the implications of high- and low-ambition interpretations of such pledges -- we have denoted the weaker interpretation to be 'unconditional' and the stronger interpretation to be 'conditional'.