World on track for a 2.5-2.9°C temperature rise: UN’s emissions gap report

In the most optimistic scenario, the likelihood of limiting warming to 1.5°C is only 14%, says report 

As global temperatures and greenhouse gas emissions break records, the latest Emissions Gap Report from the UN Environment Programme (UNEP) found that current pledges under the Paris Agreement put the world on track for a 2.5-2.9°C temperature rise above pre-industrial levels this century, pointing to the urgent need for increased climate action. 

Released ahead of the COP28, the Emissions Gap Report 2023 revealed how temperatures hit new highs, yet the world is failing to cut emissions (again). The report said that global low-carbon transformations are needed to deliver cuts to predicted 2030 greenhouse gas emissions of 28% for a 2°C pathway and 42% for a 1.5°C pathway. Maintaining the possibility of achieving the Paris Agreement temperature goals hinges on significantly strengthening mitigation this decade to narrow the emissions gap. 

This will facilitate more ambitious targets for 2035 in the next round of Nationally Determined Contributions (NDCs) and increase the chances of meeting net-zero pledges, which now cover around 80% of global emissions. “There is no person or economy left on the planet untouched by climate change, so we need to stop setting unwanted records on greenhouse gas emissions, global temperature highs and extreme weather,” said Inger Andersen, Executive Director of UNEP. “We must instead lift the needle out of the same old groove of insufficient ambition and not enough action, and start setting other records: on cutting emissions, on green and just transitions and on climate finance.

Record-breaking rise in emissions 

The report found that global greenhouse gas (GHG) emissions increased by 1.2% from 2021 to 2022 to reach a new record of 57.4 Gigatonnes of Carbon Dioxide Equivalent (GtCO2e). GHG emissions across the G20 increased by 1.2% in 2022. Emissions trends reflected global patterns of inequality, the report noted. Because of these worrying trends and insufficient mitigation efforts, the world is on track for a temperature rise far beyond the agreed climate goals during this century.  

Until the beginning of October this year, 86 days were recorded with temperatures over 1.5°C above pre-industrial levels. September was the hottest recorded month ever, with global average temperatures 1.8°C above pre-industrial levels.

If mitigation efforts implied by current policies are continued at today’s levels, global warming will only be limited to 3°C above pre-industrial levels in this century. Fully implementing efforts implied by unconditional Nationally Determined Contributions (NDCs) would put the world on track for limiting temperature rise to 2.9°C. Conditional NDCs fully implemented would lead to temperatures not exceeding 2.5°C above pre-industrial levels. All of these are with a 66% chance.

Current unconditional NDCs imply that additional emissions cuts of 14 GtCO2e are needed in 2030 over predicted levels for 2°C and cuts of 22 GtCO2e are needed for 1.5°C. The implementation of conditional NDCs reduces both these estimates by 3 GtCO2e.

In percentage terms, the world needs to cut 2030 emissions by 28% to get on track to achieve the 2°C goal of the Paris Agreement, with a 66% chance, and 42% for the 1.5°C goal. If all conditional NDCs and long-term net-zero pledges were met, limiting the temperature rise to 2°C would be possible. 

However, the report added, net-zero pledges are not currently considered credible as none of the G20 countries are reducing emissions at a pace consistent with their net-zero targets. Even in the most optimistic scenario, the likelihood of limiting warming to 1.5°C is only 14%. 

Not enough progress

Policy progress, since the Paris Agreement was signed in 2015, has reduced the implementation gap, defined as the difference between projected emissions under current policies and full NDC implementation. GHG emissions in 2030 based on policies in place were projected to increase by 16% at the time of the adoption of the Paris Agreement. 

Today, the projected increase is 3%. As of September 25, 2023, nine countries had submitted new or updated NDCs since COP27 in 2022, bringing the total number of updated NDCs to 149. If all new and updated unconditional NDCs are fully implemented, they would likely reduce GHG emissions by about 5.0 GtCO2e, about 9% of 2022 emissions, annually by 2030, compared with the initial NDCs. 

However, unless emission levels in 2030 are brought down further, it will become impossible to establish least-cost pathways that limit global warming to 1.5°C with no or low overshoot during this century. Significantly ramping up implementation in this decade is the only way to avoid significant overshoot of 1.5°C.

Carbon dioxide removal 

The report also found that delaying GHG emissions reductions will increase future reliance on carbon dioxide removal from the atmosphere. Carbon dioxide removal is already being deployed, mainly through afforestation, reforestation and forest management. Current direct removals through land-based methods are estimated at 2 GtCO2e annually. However, least-cost pathways assume considerable increases in both conventional and novel carbon dioxide removal—such as direct air carbon capture and storage

Achieving higher levels of carbon dioxide removal remains uncertain and associated with risks around land competition, protection of tenure and rights and other factors. Upscaling of novel carbon dioxide removal methods are associated with different types of risks, including that the technical, economic and political requirements for large-scale deployment may not materialise in time. A recent research also outlined several kinds of legal risks associated with countries’ insufficient efforts in reducing emissions and their excessive reliance on carbon dioxide removal to achieve Paris targets.

The urgent need for low-carbon development transformations

The report called for all nations to deliver economy wide, low-carbon development transformations, with a focus on the energy transition. The coal, oil and gas extracted over the lifetime of producing and planned mines and fields would emit over 3.5 times the carbon budget available to limit warming to 1.5°C, and almost the entire budget available for 2°C. 

The report said that countries with greater capacity and responsibility for emissions—particularly high-income and high-emitting countries among the G20—will need to take more ambitious and rapid action and provide financial and technical support to developing nations. As low- and middle-income countries already account for more than two-thirds of global GHG emissions, meeting development needs with low-emissions growth is a priority in such nations—such as addressing energy demand patterns and prioritising clean energy supply chains.

The low-carbon development transition poses economic and institutional challenges for low- and middle-income countries, but also provides significant opportunities. Transitions in such countries can help to provide universal access to energy, lift millions out of poverty and expand strategic industries, the report said. 

The associated energy growth can be met efficiently and equitably with low-carbon energy as renewables get cheaper, ensuring green jobs and cleaner air. To achieve this, the report recommended international financial assistance will have to be significantly scaled up, with new public and private sources of capital restructured through financing mechanisms—including debt financing, long-term concessional finance, guarantees and catalytic finance—that lower the costs of capital. 

COP28 around the corner 

The first Global Stocktake (GST), concluding at COP28, will inform the next round of NDCs that countries should submit in 2025, with targets for 2035. Global ambition in the next round of NDCs must bring GHG emissions in 2035 to levels consistent with 2°C and 1.5°C pathways, while compensating for excess emissions until levels consistent with these pathways are achieved. 

The preparation of the next round of NDCs offers the opportunity for low- and middle-income countries to develop national roadmaps with ambitious development and climate policies, and targets for which finance and technology needs are clearly specified. COP28 should ensure that international support is provided for the development of such roadmaps.

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