Recently, assessments have robustly linked stabilisation of global-mean temperature rise to the necessity of limiting the total amount of emitted carbon-dioxide (CO2). Halting global warming thus requires virtually zero annual CO2 emissions at some point.
Policymakers have now incorporated this concept in the negotiating text for a new global climate agreement, but confusion remains about concepts like carbon neutrality, climate neutrality, full decarboniaation, and net zero carbon or net zero greenhouse gas (GHG) emissions. Here we clarify these concepts, discuss their appropriateness to serve as a long-term global benchmark for achieving temperature targets, and provide a detailed quantification.
We find that with current pledges and for a likely (>66%) chance of staying below 2 °C, the scenario literature suggests net zero CO2 emissions between 2060 and 2070, with net negative CO2 emissions thereafter. Because of residual non-CO2 emissions, net zero is always reached later for total GHG emissions than for CO2. Net zero emissions targets are a useful focal point for policy, linking a global temperature target and socio-economic pathways to a necessary long-term limit on cumulative CO2 emissions.
Unabated: the Carbon Capture and Storage 86 billion tonne carbon bomb aimed at derailing a fossil phase out
The climate talks at COP28 have centred around the need for a fossil fuel phase out. Our analysis quantifies the risk posed by restricting a phase out commitment to only ‘unabated’ fossil fuels.
No change to warming as fossil fuel endgame brings focus onto false solutions
The CAT's annual warming estimate has risen by 0.1˚C to 2.5˚C. The estimate is largely influenced by weak existing targets rather than shifts triggered by updated Nationally Determined Contributions.
When will global greenhouse gas emissions peak?
The IPCC says peaking before 2025 is a critical step to keep the 1.5°C limit within reach. With emissions set to rise in 2023, this leaves limited time to act. To assess if we can meet this milestone, we look at when global emissions might peak, as well as what we can do to get there in time.
Wind and solar benchmarks for a 1.5°C world
This report presents a detailed methodology for determining the amount of wind and solar capacity that is required for a country to align with the Paris Agreement’s 1.5°C temperature goal. While the focus of the report is the method, it includes illustrative benchmarks for Brazil, China, India, Indonesia, Germany, South Africa.
A 1.5°C future is possible: getting fossil fuels out of the Philippine power sector
The Philippines is also one of the fastest-growing developing countries: poverty is in decline, access to energy is rising and, with that, demand for energy services. However, fossil fuels still dominate the energy system, accounting for 78% of power generation in 2022. This report sets out what the Philippines government needs to do to get the country’s power sector onto a 1.5˚C compatible emissions pathway, replacing fossil fuels with renewable energy.
Production Gap Report 2023
Governments, in aggregate, still plan to produce more than double the amount of fossil fuels in 2030 than would be consistent with limiting warming to 1.5°C. The persistence of the global production gap puts a well-managed and equitable energy transition at risk.
Emissions impossible: Unpacking CSIRO GISERA Beetaloo Middle Arm fossil gas emissions estimates
This report provides an independent evaluation of the CSIRO and GISERA assessments of the potential greenhouse gas emissions that would result from the exploitation of the Beetaloo fossil shale gas reserves.
Adjusting 1.5°C climate change mitigation pathways in light of adverse new information
This study uses an integrated assessment model to explore how 1.5°C pathways could adjust in light of new adverse information, such as a reduced 1.5°C carbon budget, or slower-than-expected low-carbon technology deployment.
The effects of political knowledge use by developing country negotiators in Loss and Damage negotiations
This article traces how developing country negotiators used knowledge to further their interests in loss and damage negotiations from 2003 to 2013.
Railway development: lessons for the EU
This paper analyses how EU railway policy for a low-carbon future can be enhanced, drawing insights from Japan and Switzerland.