The Carbon Space Implications of Net Negative Targets

Carbon space consumption if the three largest polluters reached net negative emissions in their current target years
 

The Government of India and many scholars have time and again emphasised the need for large developed economy polluters to become net negative by 2050 to free up additional carbon space for developing countries. If the three largest emitters — China, the US and the EU — sequestered additional carbon dioxide over and above the net-zero target, they would collectively sequester 202 GtCO2 between 2050 and 2100. This would free up significant carbon space for India and other Asian, African and Latin American nations to pursue their developmental agendas. This still implies that China’s post-2020 emissions would account for 23.8 per cent of the 1.5°C global carbon space. Ideally, the sequestration of carbon should begin much earlier to reduce the risks of breaching planetary tipping points.

It is evident that to stay below 1.5°C and distribute the global carbon space equitably, the world’s three largest emitters need to increase their emissions reduction efforts significantly. Their current net-zero targets simply do not meet the bar for climate ambition and explicitly violate the principle of climate justice. The analysis highlights that merely advancing the net-zero year will not be enough. These nations need to aim for negative emissions in the long term to support the growth of the developing world. The global net-zero agenda should shift to a net negative agenda for the developed world and China.

Source: Spring and Paraguassu (2021); Governo do Brazil (2021); Government of Canada (2021); Hughes (2021); European Union
(2020); BBC (2021); Climate Watch (2021a,b,c,d); Government of India (2018); McKinsey (2021); Takenaka, Takemoto and Obayashi
(2021); Carbon Brief (2020); Climate Action Tracker (2021); Cha (2020); The White House (2021); IISD (2021)

Historical data source

The analysis involved collecting historical emissions data, estimating future emission trajectories, and evaluating the share of carbon space consumed by the leading emitting nations. For this analysis, we have considered the following nations: China, the US, India, the EU, the Russian Federation, South Korea, Japan, Canada, Mexico, and Brazil. These countries were chosen based on their relatively high current share in total global emissions and the availability of explicit public information regarding their future vision and targets.

Methodology

Annexure

The emissions timeline considered in this analysis is 1850-2100. We considered total CO2 emissions excluding forestry/ Land Use, Land-Use Change and Forestry (LULUCF). Historical emissions trajectories follow from 1850-2019. Our primary source of historical emissions was WRI’s Climate Watch; however, to complete the entire series, we also considered the World Bank’s CO ₂ emissions5 trajectory. Notably, the consistency of the variable is maintained across sources. For the 1850-1899 period, we took emissions data from WRI Climate Watch’s PIK database. For the 1990-2011 period, we considered data from WRI Climate Watch’s CAIT database. For the 2012-2018 period, we considered data from the World Bank’s emissions data repository. Finally, we use the rate of change of emissions between 2019-2021 from the Climate Action Tracker’s database to estimate emissions for 2019, 2020 and 2021, based on 2018 World Bank data. For this analysis, we used the carbon budgets described in the IPCC’s AR 6 report for 1.5 (400 GtCO₂ ) and 2.0 °C (1150 GtCO₂ ) targets for the 67 ^th percentile (IPCC 2021).

Future emissions data source

For the future trajectory of emissions, we considered the countries’ proposed pledges up to 2030. These included commitments under NDCs or any other mitigation efforts (see the table below).

To incorporate the NDC pledges mentioned above, we considered a linear decline in emissions between the 2021 emission level and emission targets up to 2030. Further, we assumed a linear reduction in emissions from 2030 levels to the net-zero year. India recently announced 2070 net-zero, which is considered in this analysis. As described in Chaturvedi and Malyan (2021), for the 2070 net-zero scenario for India, 2040 is considered as a peak year. Mexico and the Russian Federation have not taken a position on net-zero targets. For the analysis, we assume 2060 as the net-zero year for these two countries. However, it should not be assumed Mexico, and the Russian Federation will actually adopt these timelines, or that we recommend that they do so.

To understand the implications of advancing the netzero years of the world’s three largest economies, we assume a 10-year advancement of the proposed net-zero years for the US, the EU, and China in our second scenario. We assume that the US and the EU target 2040 for achieving a net-zero economy while emissions decline starts immediately, and that China targets a 2050 net-zero year and advances its peaking year to 2025. However, other countries remain on the track considered in the current pledges scenario.

In the third scenario we considered, the US, the EU, and China countries not only advance their net-zero years but go on to achieve net-negative emissions. We assume that the US and the EU will sequester 1 GtCO₂ starting in 2050, and that China will sequester 2 GtCO₂ from 2060 onwards. We maintained the differentiation between the EU/the US and China is because of the massive size of the China’s energy economy. Between the net-zero year and the net-negative plateauing year, we considered the linear change in emissions.

Emissions reduction commitments and long-term carbon neutrality targets for selected nations