A new United Nations Environment Programme (UNEP) report warns that nations must commit to reducing greenhouse gas emissions by 42% by 2030 and 57% by 2035 in the upcoming Nationally Determined Contributions (NDCs), and take swift action, or the Paris Agreement’s goal to limit global warming to 1.5°C will be out of reach within a few years. UNEP’s ‘Emissions Gap Report 2024: No More Hot Air…Please!’ highlights that without significantly heightened ambition in the new NDCs, temperatures could rise by 2.6-3.1°C this century, with catastrophic consequences for people, the planet, and economies.
Updated NDCs are to be submitted early next year ahead of the COP30 climate talks in Brazil. The report notes that if only current unconditional and conditional NDCs are fully implemented, warming could be limited to 2.6°C. In comparison, unconditional NDCs alone would lead to 2.8°C, and current policies alone would result in 3.1°C by the century’s end. Although additional net-zero pledges could reduce warming to 1.9°C, the confidence in implementing these pledges remains low.
“The emissions gap is not abstract,” said UN Secretary-General António Guterres in a video message on the report. “There’s a direct link between rising emissions and more frequent, intense climate disasters, with terrible consequences worldwide. Record emissions mean record sea temperatures, fueling monster hurricanes, extreme heat making forests tinderboxes, and record rains causing catastrophic floods. Today’s report is clear: we’re playing with fire; no more playing for time. We’re out of time. Closing the emissions gap means closing the ambition, implementation, and finance gaps – starting at COP29.”
To limit global warming to below 2°C, emissions must drop by 28% by 2030 and 37% by 2035 from 2019 levels, with 2035 set as a new target year in the next NDCs. UNEP Executive Director Inger Andersen called the current situation a “climate crunch time,” urging every nation to act now. “If we miss the 1.5°C target, the consequences worsen, but every fraction of a degree counts in saving lives, protecting economies, avoiding damages, conserving biodiversity, and quickly correcting any temperature overshoot.”
The report underscores the consequences of delayed action. Emission cuts required are based on 2019 levels, but greenhouse gas emissions hit a record high of 57.1 gigatons of CO₂ equivalent in 2023. This delay now requires annual reductions of 7.5% until 2035 to stay on the 1.5°C pathway and 4% for 2°C. Every year’s delay increases the magnitude of these cuts.
The report identifies a technical potential for cuts up to 31 gigatons of CO₂ equivalent by 2030, which represents about 52% of 2023 emissions, and 41 gigatons by 2035 – bridging the gap to the 1.5°C goal at an estimated cost below $200 per ton of CO₂. Expanding solar photovoltaic and wind energy could account for 27% of the potential cuts in 2030 and 38% in 2035, while forest preservation could deliver around 20% in both years. Additional impactful measures include efficiency improvements, electrification, and fuel-switching in buildings, transport, and industry.
This technical potential supports COP28’s targets to triple renewable energy capacity by 2030, double the global rate of energy efficiency improvements, shift from fossil fuels, and conserve, protect, and restore nature and ecosystems. Realising this potential will require an unprecedented global mobilisation and coordinated government action to maximise social and environmental benefits.
Achieving net-zero emissions by 2050 will demand a six-fold increase in mitigation investment, supported by reforms in global finance, active private sector involvement, and international cooperation. UNEP estimates this investment at $0.9-2.1 trillion annually from 2021 to 2050, which would yield returns in reduced costs from climate impacts, air pollution, environmental damage, and health impacts. By comparison, the global economy and financial markets are valued at $110 trillion annually.
The G20, responsible for the bulk of emissions, has a leading role in this effort, but many members remain off-track to meet their current NDCs. This group, which represents 77% of emissions and recently added the African Union as a permanent member, will need to step up its commitments. Differentiated responsibilities and increased climate finance will be essential to support both G20 members and global climate objectives.
To ensure these NDCs are impactful, UNEP recommends they be specific, transparent, and well-designed. NDCs must include all greenhouse gases, cover all sectors, define specific targets, and detail both conditional and unconditional elements. Nations should also explain how their NDCs reflect a fair share of global effort and maximise ambition. Additionally, each country should align its NDC with national sustainable development goals, provide clear implementation plans, and establish mechanisms for review and accountability. For emerging markets and developing economies, NDCs should outline the international support and financing required to meet these goals.