Zeke Hausfather at Carbon Brief summarises the UNEP 2021 Emissions Gap report, released last week. It explores the impact of the net-zero emissions pledges of nations, and the “gap” between them and the Paris targets. As COP26 gets started, 136 countries either have some form of commitment to a net-zero target or are considering it. Of those, 49 plus the EU have a firm net-zero commitment. But only 11 countries have targets enshrined in law. Hausfather draws attention to the major issues, including the near absence of any “green” Covid recovery so far, the (very slow) closing of the emissions gap, existing fossil-fuel production plans, and the temperature projections for “current policies”, “stated policies” and yet-to-be-honoured “pledges”. Limiting warming to below 1.5°C (without the use of carbon capture) would require a roughly 14% cut each year from now through to 2040. Yet emissions are on the rise again. COP26 clearly has a great deal of work to do.
Despite stronger climate policy and higher ambition in the latest national pledges, there is still a large gap between near-term commitments under the Paris Agreement and what would be needed to limit warming to well-below 2C and aim for below 1.5C.
That is the conclusion of the UNEP 2021 Emissions Gap report, which explores the impact of new pledges and the “gap” to the Paris targets. (Carbon Brief’s archives include detailed coverage of the annual UNEP reports in 2014, 2015, 2016, 2017, 2018, 2019 and 2020).
The new report finds that, while 121 countries have submitted updated Nationally Determined Contributions (NDCs) under the terms of the Paris Agreement in the lead-up to the COP26 summit in Glasgow, the effect of these is relatively limited.
Emission-cut Gap: a quarter of what’s needed for 2°C
Compared with the previous NDCs, the new pledges are expected to cut global greenhouse gas (GHG) emissions in 2030 by about 2.9bn tonnes of CO2 equivalent (GtCO2e).
To put the world on track for below 2C warming by 2100, countries must commit to reduce emissions by an additional 11-13GtCO2e by 2030, it says, and by 25-28GtCO2e for 1.5C.
No “green” recovery
Last year, UNEP had highlighted hopes of a “green recovery” from Covid-19, but this has largely failed to materialise, the report finds. While global emissions will likely remain below their 2019 peak in 2021, the difference will be relatively small, with much of the Covid-19 emissions declines already erased as the global economy recovers.
With each year that emissions increase or remain flat, the 1.5C goal is slipping further out of reach, UNEP says. Limiting global warming to the “well below” 2C goal is also becoming more difficult with every passing year in which emissions continue to grow.
The UNEP report finds that, under current policies, the world will likely warm by around 2.6C by 2100, with an uncertainty range of up to 3.5C given uncertainties in emissions pathways and climate system responses to emissions.
If countries meet both conditional and unconditional NDCs this would be reduced to 2.4C (with a range up to 3.3C). And if countries meet all of their announced mid-century net-zero targets it would be around 2C (with a range up to 2.8C).
As of 13 September, the report counts countries representing approximately 57% global GHG emissions as having committed to reach net-zero in the mid-21st century. (This does not include recent commitments from Russia, Turkey, Saudi Arabia or Australia.)
Only a small subset have enshrined these targets into law and the report stresses that there is an “urgent need to back these pledges up with near-term targets and actions”.
Emissions rapidly recovering from Covid-19 lull
Each UNEP report analyses the previous year’s emissions. However, this year’s report also includes some analysis of 2021’s projected emissions, thanks to new tools such as Carbon Monitor that provide updates on global emissions in close-to-real time.
The new report shows that global fossil CO2 emissions fell by 5.4% in 2020 compared to 2019. Emissions were down in almost virtually every country on Earth. By contrast, it projects a strong rebound in 2021 as countries recover from the Covid-19 pandemic.
While global fossil CO2 emissions in 2021 are projected to remain about 1% below 2019 levels, a number of countries including China, Russia and Brazil are expected to exceed their pre-pandemic 2019 levels this year.
The figure below, from the new UNEP report, shows the change in national emissions during 2019-2020 (pink bars) and between 2019 and 2021 (purple). China plays a large role in holding up the global total this year, with roughly an 8% rise projected relative to 2019 levels.
Relatively insignificant low-carbon recovery investment
The 2020 UNEP report expressed considerable hope that countries could use economic stimulus efforts to promote a “green recovery” from Covid-19, helping accelerate the transition away from fossil fuels.
A year later, however, the report suggests that most countries have not seriously pursued this path. As the UNEP report explains:
“Most governments have so far failed to prioritise a transformative low-carbon recovery, with the relatively insignificant low-carbon investment announced to date likely to maintain current unsustainable situations.”
As of May 2021, only between 2.5% and 12.1% of the $16.7tn in global Covid-19 spending has either been explicitly focused on low-carbon technologies or has had meaningful mitigation co-benefits, it finds.
The overwhelming majority of this has been in wealthy countries, whereas middle-income and poorer countries have made little-to-no green recovery spending.
The figure below, from the report, shows Covid-related fiscal and recovery spending in G20 countries in total and as a share of national GDP rated by emission impact, from highly negative (red), to negative (orange), relatively neutral (yellow), positive (light green) or highly positive (dark green).
Only South Korea, the UK, Italy, Canada, and Germany have had notable positive spending, according to the report. While it is not too late to rebalance additional spending toward emissions mitigation goals, the window to make a meaningful impact is quickly closing.
A slowly narrowing emissions gap
The figure below, adapted from the report, shows UNEP’s latest emissions gap analysis at a glance. Emission trajectories associated with policies that were in place in 2010 – but nothing after that point – are shown in red and current policies already implemented by governments in orange.
Additional commitments in NDCs that are not yet implemented are shown in yellow for unconditional commitments and light blue for those conditional on aid or action by other countries. Emission trajectories consistent with staying below 2C, 1.8C and avoiding 1.5C are shown in blue, purple and grey, respectively.
[Median emission scenarios adapted from Figure 3.1 in the UNEP Emission Gap Report 2021. Red line shows a scenario with no new climate policies after 2010, orange shows existing policies already implemented by governments, yellow and light blue lines show additional conditional and unconditional NDCs, blue line shows emissions consistent with a below 2C trajectory, purple line below 1.8C, and grey line shows emissions consistent with a 1.5C trajectory. Chart by Carbon Brief using Highcharts.]
There is a large gap between what countries have committed to, in terms of future emission reductions, and what would be needed to meet the Paris Agreement goals.
Current NDCs would result in global emissions plateauing in the mid-2020s and only modestly declining through to 2030, UNEP says. They would leave the world in 2030 some 11-13GtCO2e short of a path to below 2C and 25-28GtCO2e short for 1.5C.
The 2021 emissions gap is modestly smaller than was reported in the 2020 UNEP report – by 1-2GtCO2e for limiting warming below 2C and 4GtCO2e for 1.5C.
However, this small difference masks a much larger change between reports: the 2021 report lowers current policy projections of emissions in 2030 by 4GtCO2e.
This is the first time the current policy scenario has been substantively updated since the 2017 UNEP report and reflects the accelerated adoption of policies by countries, declining clean energy costs, as well as some effects of the Covid-19 pandemic on emissions projections.
Similarly, the 2030 emissions outcomes associated with unconditional and conditional NDCs were lowered by 4GtCO2e and 2.9GtCO2e, respectively – also representing the first update in projected emissions if countries meet their NDCs since 2017.
In addition to the emissions gap report, UNEP recently published a 2021 Production Gap report highlighting the difference between fossil-fuel production plans by countries, fossil-fuel production implied by climate pledges, and what would be needed to limit warming to well below 2C or below 1.5C, as shown in the figure below.
[Emission scenarios adapted from Figure 2.1 in the UNEP Production Gap Report 2021. Red line shows country plans and projections, orange shows production implied by climate pledges, blue line shows emissions consistent with a below 2C trajectory and grey line shows emissions consistent with a 1.5C trajectory. Chart by Carbon Brief using Highcharts.]
Country-level fossil-fuel production plans imply an emissions gap of 17.8GtCO2 in 2030 compared to what would be needed to limit warming to well-below 2C and 24.5GtCO2 compared to the below-1.5C scenario.
If current pledges are taken into account, this production gap shrinks modestly to 14.8GtCO2 compared with a well-below 2C scenario and 21.5GtCO2 for below-1.5C.
More countries have set net-zero targets
While a large emissions gap remains between current NDCs and what would be needed for 1.5C and 2C scenarios, there is some reason for cautious optimism. An increasing number of countries have set net-zero emission targets, with a number of major emitters announcing 2050 or 2060 targets over the past two years.
Currently 136 countries either have some form of commitment to a net-zero target or are considering it. The UNEP emissions gap report identifies 50 parties to the UN Framework Convention on Climate Change (UNFCCC), including 49 countries plus the European Union, that have a firm net-zero commitment reflected in a statement in national legislation, in a policy document such as an NDC, or a public announcement by the government or a head of state or similar high-level government official.
(UNEP’s list reflects developments up to 13 September 2021, meaning it misses recent commitments by Turkey, Russia, Saudi Arabia and Australia.)
…but only 11 countries have targets enshrined in law
The 50 countries identified by UNEP cover 57% of global GHG emissions and include major emitters such as the UK, US, EU, China, Japan, Korea, Canada, South Africa, Argentina and Mexico. However, there is a large difference between announced long-term climate targets and the short-to-medium term actions needed to accomplish them.
As the UNEP report points out, only 11 countries have targets enshrined in law, covering 12% of global emissions. The extent to which these long-term targets should be taken seriously will depend on how they are translated into firmer near-term commitments.
Where the world is heading today
A decade ago, the world appeared to be on track for extreme warming, with scenarios for 4C or 5C and a doubling or tripling of emissions by the end of the century appearing plausible.
A number of different groups have assessed likely climate outcomes under policies in place today, stated policies and pledges, such as Paris NDCs, and long-term net-zero targets.
[Global mean surface warming projections in 2100 relative to preindustrial levels from the UNEP Emissions Gap report, Climate Action Tracker (CAT) and IEA World Energy Outlook 2021. Bars show the central (50th percentile) estimate, while uncertainties are shown in brackets. The Stated Policies value refers to the “Conditional NDC” case for UNEP. For the IEA, Stated Policies does not automatically imply NDCs are met. Note that UNEP only provides the upper bound of uncertainty. For UNEP, uncertainties from post-2030 emissions pathways and climate system uncertainties were assumed to be independent and added in quadrature. Chart by Carbon Brief using Highcharts.]
In a world characterised by policies in place today – where no additional climate policies are enacted prior to 2100 – UNEP estimates that the world will most likely warm by around 2.6C, with a 90th percentile estimate of 3.5C.
This is notably lower than the CAT estimate of 2.9C (ranging from 2.1C to 3.9C) and also lower than the estimate provided in the 2020 emissions gap report.
The reduction relative to the 2020 report reflects the adoption of additional climate policies as well as some effects of the Covid-19 economic downturn. The drivers of the difference between UNEP and CAT current policy warming estimates is unclear.
In a world where countries meet their stated policies, including NDC commitments, UNEP and CAT both project around 2.4C warming, with warming up to 3.3C possible in UNEP’s estimate and 1.9C to 3C in CAT’s estimate. UNEP includes only NDC commitments (both conditional and unconditional) in the values shown in the figure above, while the CAT definition of stated policies (which they call “pledges and targets”) is a bit more expansive, incorporating near-term pledges that might not have been translated into formal NDCs.
The IEA projects around 2.6C warming (1.9C to 3.7C) in its stated policy scenario. The IEA scenario does not necessarily assume countries will all meet their NDCs; rather, it takes a case-by-case approach to judging whether specific sectoral pledges will be met.
Finally, if all countries that had made such commitments by mid-September meet their pledges to reach net-zero emissions in 2050 or 2060, the UNEP and CAT both project around 2C warming by 2100 – with up to 2.8C possible in UNEP and a range of 1.6C to 2.6C in CAT. IEA provides a similar estimate of 2.1C, with a range of 1.5C to 3C.
While the figure above highlights 50% outcomes, the UNEP report tends to focus on 66% outcomes, meaning the warming level that the world has a 66% chance of avoiding. These figures are a bit higher, with a central estimate of 2.8C for current policies, 2.6C for conditional NDCs and 2.2C for net-zero pledges.
What it would take to limit warming to 2°C or 1.5°C
There is relatively little carbon budget remaining for warming to be limited to 1.5C. With 2021 emissions expected to be slightly below those in 2019, there will be only around 417GtCO2 – or 10 years of current emissions – remaining that can be emitted before the world has a 50/50 chance of exceeding 1.5C warming.
For a 66% chance of avoiding 1.5C warming, the remaining carbon budget after 2021 would only be around 317GtCO2 – or around seven years of current emissions.
While this carbon budget can be expanded through the widespread use of negative emissions technologies (NETs) later in the century – as occurs in the 1.5C scenarios in the new IPCC report – there is some reluctance to bet the future on NETs that are largely unproven at scale today.
The figure below, adapted from one created by CICERO’s Dr Robbie Andrews, shows emission trajectories to limit warming to below 1.5C in the absence of net-negative emissions. The different lines show the emissions reductions that would be required if emissions had peaked in each year, between 2000 and 2030, with the current year (2021) highlighted in grey.
[Emission reduction trajectories associated with a 66% chance of limiting warming below 1.5C, without a reliance on net-negative emissions, by starting year. Solid black line shows historical emissions, while dashed black line shows emissions constant at 2021 levels. Source: Historical CO2 emissions from the Global Carbon Project. 1.5C carbon budgets based on the IPCC AR6 report. Original figure from Robbie Andrews. Chart by Carbon Brief using Highcharts.]
If emissions had peaked and begun to decline after 2000, the 1.5C target would have been much easier to achieve, only requiring reductions of around 3% per year. By contrast, limiting warming to below 1.5C starting in 2021, without the use of NETs, would require a roughly 14% cut each year through to 2040.
With the inclusion of NETs, it is possible to create scenarios to limit warming below 1.5C that do not involve quite so precipitous a drop in emissions in the coming years. However, these rely on planetary scale deployment of NETs in order to “suck” an amount from the atmosphere equivalent to between a quarter and half of the world’s current human-caused emissions from the atmosphere each year.
Each year that passes without global emission reductions puts the 1.5C target further out of reach, says the UNEP report. While the Paris Agreement’s “well below” 2C target is easier to achieve than 1.5C, delays will make it increasingly difficult, too.
Carbon Brief’s interactive chart below shows the emission reductions needed, by peaking year, to meet the 2C target without use of net-negative emissions.
[Emission reduction trajectories associated with a 66% chance of limiting warming below 2C without net-negative emissions, by starting year. Solid black line shows historical emissions, while dashed black line shows emissions constant at 2021 levels. Source: Historical CO2 emissions from the Global Carbon Project. Below-2C carbon budgets based on the IPCC AR6 report. Original figure from Robbie Andrews. Chart by Carbon Brief using Highcharts.]
The gap between what is actually occurring and what is needed to limit warming to Paris Agreement targets of 1.5C and 2C continues to grow larger with each passing year, necessitating ever steeper future reductions.
While the recent net-zero commitments by a number of major emitting nations are an important step in the right direction, UNEP says the proof will be in the extent to which countries “back these pledges up with near-term targets and actions that give confidence that net-zero emissions can ultimately be achieved and the remaining carbon budget kept”.
Zeke Hausfather is a climate science contributor for Carbon Brief