What is the carbon budget that remains — the amount of carbon dioxide we can emit going forward if we are to limit temperature rise to 1.5°C?
In the coming 10 years, China will take up 3 per cent of the remaining carbon budget. Despite heavy reduction targets, the original seven emitters, along with China, will occupy 62 per cent. The remaining world, with 66 per cent of the population, will be left with 38 per cent.
In its Sixth Assessment Report (AR6), IPCC does not include the historical budget but states that the remaining budget is 400 Gigatonne of carbon dioxide (CO2) for the world to have a 66 per cent probability of staying below 1.5 degree Celsius.
Till 2019, the world had emitted 1,642 GtCO2. If the IPCC Fifth Assessment Report (AR5) budget is used, then this would mean that 73 per cent of the budget had been exhausted and 608.3 GtCO2 remains.
But now we know that only 400 GtCO2 remains to keep the world below 1.5°C rise, according to the revised estimate published in AR6. Then we need to know that this carbon budget includes emissions from land use, land-use change and forestry, roughly 3.3 per cent. If this is deducted, then the world has a remaining carbon budget for fossil fuel emissions of 387 Gt from 2020 to keep it below 1.5°C, as per AR6.
It should not be a surprise to learn that the world will exhaust the remaining carbon budget before 2030 — even assuming the complete implementation of nationally determined contributions (NDC) by countries. This itself is a huge question mark because big emitters, like the United States, have ambitious plans, but as yet these seem to be stuck and it is difficult to say if the scale of reduction will be achieved at all.
In the current decade — billed rightly as the last chance to avert catastrophic climate change — we see some change.
Of the historical emitters, the US, the European Union (EU-)27, the United Kingdom and Canada have put forward substantial reduction targets. If these are realised — and there are still questions about this — the contribution of this group of countries to the world’s emissions in the decade will reduce from 21.19 per cent to 19.47 per cent.
However, this is still not a “fair share” — not by a stretch — if you take the contribution of these countries to the stock of emissions already in the atmosphere, which is in fact the cause of the temperature rise. Between 1870 and 2030, these countries with minuscule global populations will still account for nearly half the CO2 emissions in the atmosphere even if their NDCs are achieved.
But what makes the last-chance decade even more inequitable is the enduring rise of the world’s next superpower, China. In this decade, China has not given any emission reduction targets — only a commitment to reduce its carbon dioxide emissions per unit of GDP by 65 per cent from the 2005 levels.
According to our estimate, China’s emissions in 2030 would be 12.65 Gt — up from 10.17 Gt in 2019. This is also what has been estimated by Climate Action Tracker.
The tracker says that “under China’s most binding peaking and non-fossil share NDC targets, the country’s emission levels would reach between 13.2 to 14.0 GtCO2e in 2030, an increase of 20 per cent to 28 per cent from 2010 levels.”
Based on our estimate, China will emit 126 Gt of CO2 in the coming 10 years. This means that its emissions will take up 33 per cent of the left over carbon budget, as per AR6.
As a result, the original 7+China will occupy 62 per cent of the budget, for this decade. Seen as a whole — from 1870 onwards to 2030, even if NDCs are achieved — these countries will be responsible for 71 per cent of the world's emissions.
In 2030 the per capita — carbon dioxide emissions by the population will remain inequitable.
How fair is this? In what world, language or situation can this be called okay?
The problem is not even a theoretical or moralistic idea. The fact is that roughly 30 per cent of the carbon budget is available for the vast numbers of people in the world, who still do not have access to energy and are way down on any human development indicator.
Now unless we can tell these billions to stop breathing, or stop development, or stop everything that we know today makes the world economy prosperous, they will emit. As a result, the world will breach the guardrail of 1.5°C temperature rise.
This is why equity is a pre-requisite to an ambitious and effective climate agreement. It is not something that can be diluted, discarded or erased.
Dissect, dice and slice the data any which way and the conclusion will be the same — few countries have appropriated the carbon budget and their accumulated emissions are the cause of the temperature increase, which is taking the world towards catastrophe.
There is the other inconvenient truth that if the rich (including China) polluted yesterday and today, then the remaining world (roughly 70 per cent of the world still needs right to development). This part of the world cannot be wished away, it cannot be shouted and screamed at and bullied, into a low-carbon pathway.
This transformation — growing, but with the emissions that will further jeopardise the world — will need huge funding and technology support. This is not about charity, but about fixing what has been broken, in the interest of all.
The story in numbersChina and the developed world will continue to have the lion's share of the planet's carbon budget in 2020-30, while the burden of reducing emissions will be borne unfairly by many developing countries
is the remaining carbon budget for the world, starting 2020, to have a 66 per cent probability of staying below 1.5°C
36.4Gt is the annual amount of anthropogenic CO2 (from fossil fuel and cement) the planet emits
At the current rate, we will run out of the planet's carbon budget in 2030, even if we achieve nationally determined contributionsBudget hoggers
33 per cent of the carbon budget for the 1.5oC trajectory will be consumed by China's emissions in 2020-30
29 per cent of the carbon budget for the 1.5oC trajectory will be consumed by the original 7 polluters (US, UK, EU-27, Russia, Japan, Australia, Canada) in 2020-30
38 per cent of the carbon budget will be available for the rest of the world in 2020-30
NDCS not ambitious…
37.71GtCO2 is what the world will emit in 2030 even if it achieves enhanced NDC
...And the burden is unfair
53 per cent is the reduction in per capita emissions by 2030, compared to 2019 levels, as per NDCs pledged by Micronesia
30 per cent is the reduction in per capita emissions by 2030, compared to 2019 levels, as per NDCs pledged by by Japan and Australia
16 per cent is the hike in per capita emissions by 2030, compared to 2019 levels, as per Russia's NDCs
This was first published in Down To Earth’s print edition (dated 1-15 November, 2021)
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