numbers, not adjectives — D. J. C. MacKay
5 Equitable emissions
Equitable means fair and impartial. Interpreting what equitable means in the context of greenhouse gas emissions is an ethical and moral question. However, few would seriously contend with interpreting fair as in equal to all humans. Thus, a reasonable way to quantify emissions is using units of tons of CO2 equivalents per capita, tCO2e per person.
5.1 The past
It is well known, that in the historical perspective, per capita emissions have been very unevenly distributed; large disparities existed both between and within countries. Although unequal past emissions are indeed a concern, here I will look forward to how emissions may be distributed in the future, and in what sense we can approach equitability.
5.2 The future
Most countries have submitted Nationally Determined Contributions (NDCs) has part of their commitments under the Paris Agreements. In particular, NDC 2.0 represent the commitment to emissions for the year 2030. Below is a table with a subset of nations or regions and the NDCs (available from unfccc.int/NDCREG).
| Region | Population (millions) | NDC 2.0 (tCO2e/cap) | paraphrased NDC text (estimates from outside NDC) |
|---|---|---|---|
| Iran | 90.6 | not party to the Paris Agreement | |
| Iraq | 45.1 | no clear CO2e target | |
| Egypt | 114.5 | no clear CO2e target | |
| China | 1422.6 | 18.1 | reduce emissions intensity of GDP by 65 percent by 2030, from 2005 (2005 GDP $2.286tn, CO2e 7211 Mt; est 2030 GDP: $17.758tn in 2023 + 4% pa growth) |
| UAE | 10.6 | 17.2 | 19% reduction, base 2019: 2030 target CO2e 182 Mt |
| Australia | 21.8 | 16.2 | 43% below 2005: net CO2e 621.1 Mt |
| Russia | 145.4 | 15.0 | reduction to 70% of 1990: CO2e 3100 Mt |
| Saudi Arabia | 32.3 | 13.7 | 278 MtCO2e reduction from 2019 (2019 CO2e 721 Mt) |
| Canada | 39.3 | 11.1 | CO2e 438 Mt |
| US | 343.5 | 9.6 | 50% below 2005 (2005 net CO2e 6587 Mt) |
| South Korea | 51.7 | 8.4 | 40% reduction from 2018, CO2e 728 Mt |
| Turkey | 87.3 | 8.0 | CO2e 695 Mt |
| Vietnam | 100.4 | 7.8 | unconditional 15.8% reduction from BAU CO2e 927.9 Mt |
| Argentina | 45.5 | 7.7 | CO2e 349 Mt |
| South Africa | 63.2 | 6.6 | upper limit CO2e 420 Mt |
| Japan | 124.4 | 6.1 | CO2e 760 Mt |
| EU | 447.6 | 5.7 | 55% below 1990 (1990 CO2e 5650.4 Mt) |
| Pakistan | 247.5 | 5.5 | 15% unconditional reduction from BAU CO2e 1603 Mt |
| Brazil | 221.1 | 5.4 | CO2e 1200 Mt |
| Thailand | 71.7 | 5.4 | 30% below BAU CO2e 555 Mt |
| Mexico | 129.7 | 5.0 | 35% reduction from 991 MtCO2e baseline |
| Azerbaijan | 10.3 | 5.0 | 35% reduction base 1990 CO2e 79 Mt |
| India | 1438.1 | 4.4 | reduce emissions intensity of GDP by 45 percent by 2030, from 2005 (2005 GDP $820bn, CO2e 1585.5 Mt; est 2030 GDP $7.3tn) |
| Indonesia | 281.2 | 4.4 | CO2e 1240 Mt |
| UK | 68.7 | 3.8 | 68% below 1990 (1990 CO2e 812 Mt) |
| Malaysia | 35.1 | 2.9 | 45% reduction of GDP intensity by 2030 from 2005 (2005 GDP $143.5bn, CO2e 44.2 Mt; est 2030 GDP $492.9bn in 2025 + 4% pa growth) |
| Ethiopia | 128.7 | 2.7 | unconditional 14% reduction of BAU CO2e 403.5 Mt |
| Bangladesh | 171.5 | 2.2 | CO2e 27.56 Mt reduction from BAU CO2e 409.41 Mt |
| Nigeria | 227.9 | 1.6 | unconditional 20% reduction of BAU CO2e 453 Mt |
The regions are given with their populations, needed to work out the per capita commitment. Of course, population changes with time, but in most regions population isn’t changing rapidly, so this is only a small concern. We shouldn’t interpret these numbers for more than they are: promises of future emissions. Some countries may dishonour their promises and some may outperform theirs.
Nevertheless, it is striking how large the range of per capita emissions promises are. Addressing climate change will require absolute reductions in emissions, and managing this in a equitable way will require convergence of the range of per capita emissions. A really fundamental question is by what mechanism this can be achieved. In the Paris Agreement, the primary mechanism has been hope, that nations submit more ambitious commitments. But as the NDC 2.0 numbers in the table above suggests, with only modest success. It may be appropriate to examine more effective mechanisms.