PBL provides climate change research for UN Climate Conference (COP26)

By 27 September 2021, 120 countries (119 Parties, including the EU and its 27 Member States), representing about 50% of global greenhouse gas (GHG) emissions in 2019, had communicated new or updated Nationally Determined Contributions (NDCs). In addition, China, Japan and South Korea have announced enhanced pledges but have not yet formally communicated them to the UNFCCC.

These announcements would further increase the share of global emissions covered by NDC updates to 76%. The analysis shows that all the NDC updates, together, have an aggregated impact on global GHG emissions of about -4.0 GtCO2 eq by 2030 compared to the first round of unconditional NDCs.

Despite the increase in ambition level, the collective level of all submitted NDCs (including the updates) still falls short of what would be needed to put global emissions on to a cost-effective pathway towards achieving the climate goals of the Paris Agreement.

This report, by the NewClimate Institute, PBL and the International Institute for Applied Systems Analysis (IIASA), provides an overview of projected GHG emissions in 26 major emitting countries/regions up to 2030, taking into account the emission trajectories based on current policies and the implementation of nationally determined contributions (NDCs). It includes an update of the 2019 report, and considers the most recent NDC submissions as well as the impact of COVID-19 on GHG emissions. The report shows that emissions are projected to keep increasing in most countries, but concludes that 16 of the 26 countries and regions analysed are on track or close to achieve the NDC targets they had previously set for themselves. Eight are on track to also meet their updated NDC targets (with another two countries getting close to doing so). Eleven countries are not on track to meet their updated targets, and 5 of the 26 countries have not submitted an NDC update. As the submitted NDC updates reflect distinct ambition levels, they affect progress towards emissions targets.

The PBL Climate Pledge NDC tool addresses the following three key questions:

• What are the countries’ projected emission levels for their NDCs (including the updates and new NDC submissions) for 2030?
• Will the projected aggregated impact of the fully implemented NDCs on global emissions for 2030 be sufficient to achieve the target of limiting global temperature increase to well below 2 °C / 1.5 °C?  
• Are countries on track to meet their 2020 pledges and NDCs for the period up to 2030?

To address these questions, the tool shows the projected impact of the emission reduction proposals (2020 pledges or NDCs/INDCs) and current policies, per country and globally, on greenhouse gas emission levels up to 2030. The PBL Climate Pledge NDC tool shows the targets in these NDCs/INDCs and the pledges made earlier for 2020. For 26 major emitting Parties, the tool compares these targets with GHG emission projections under current domestic climate policies up to 2030.

Over 100 countries and regions have recently formulated so-called net-zero emission targets. A crucial question here concerns by when net-zero emissions should be achieved for the various countries. This depends on factors such as the potential for afforestation and carbon capture and storage (CCS) and the use of equity principles. This study, published in Nature Communications, can be considered a first step in the information process on setting net-zero emission targets.

New and updated Nationally Determined Contributions (NDCs) only take an additional 7.5% off projected 2030 emissions of greenhouse gases. The latest emission reduction pledges for 2030 would result in a global temperature rise of at least 2.7 °C by the end of this century. So-called net-zero commitments could limit global temperature rise by another 0.5 °C, if they were made robust and if 2030 pledges were made consistent with these commitments. These are some of the main conclusions from the 2021 Emissions Gap Report by the United Nations Environment Programme (UNEP), to which PBL Netherlands Environmental Assessment Agency contributed.

A total of 131 countries are currently discussing, have announced or have adopted net-zero emission targets, covering 72% of global emissions. If implemented, these targets could limit the projected global average temperature increase to 2.0–2.4 °C by 2100, bringing the Paris Agreement temperature goal closer within reach. However, this will only be effective if the intentions are translated immediately into short-term action to put countries on a path towards meeting their net-zero emission ambitions. Existing policies and targets that drive short-term actions are currently not consistent with the announced net-zero emission targets.

The Paris Agreement’s objective is to keep global warming to well below 2 ˚C or even 1.5 ˚C. Now, 6 years after Paris, the question arises whether countries are indeed doing enough to achieve this objective. What are the possible impacts of the pledges and national climate policies? The analysis shows that current pledges by the largest emitting countries are not in line with achieving the Paris temperature goals (i.e. the ambition gap). Moreover, in many countries, policies still need to be strengthened to achieve their pledges. PBL hosts the interactive ‘Global Stocktake’ tool, designed to measure progress on the climate goals formulated in the Paris Agreement, which includes a wide range of indicators and is based on a set of global and national models. The analysis of the Global Stocktake tool is also discussed in an article published in Nature Communications.

Fast action is needed to achieve the goals of the Paris Agreement and the Sustainable Development Goals (SDGs). Many measures to mitigate climate change also relate to achieving other SDGs, with often positive but sometimes also negative impacts. In the study 'Climate Change Measures and Sustainable Development Goals', PBL shows how climate mitigation measures affect the achievement of other SDGs achievement for several world regions. This impact is predominantly positive in all geographic regions, but the extent to which varies considerably from region to region.

The temperature targets of the Paris Agreement are chosen to reduce the risks of dangerous anthropogenic climate change. These targets can also be evaluated from a purely economic perspective, although this involves many uncertainties. Accounting for these uncertainties, a PBL study published in Nature Communications shows that limiting global temperature increase to well below 2 ^oC is nearly always also attractive from an economic perspective. If mitigation costs are low, the economically most optimal outcome is staying below 1.5 °C. These findings thus support the long-term temperature goals of the Paris Agreement.

The Paris Agreement not only stipulates to limit global average temperature increase to well below 2 °C, but also calls for ‘financial flows that are consistent with a pathway towards low greenhouse gas emissions’. A multi-model assessment shows that this requires making additional investments, but mostly reallocating them (from fossil fuels to efficiency, renewables and net integration). In scenarios limiting peak warming to below 2 °C, while coal is phased out rapidly, oil and natural gas are still used in significant amount, up to 2030, albeit at lower than current levels. This requires continued investment into existing oil and natural gas infrastructure, but, under such scenarios, investments in new fields may not be required. The results show that credible and effective policy action is essential for ensuring the efficient allocation of investments aligned with medium-term climate targets.

The 2 °C and 1.5 °C temperature targets of the Paris Agreement can be interpreted as targets never to be exceeded or as end-of-century targets. Recent literature proposes to move away from the latter to avoid a temperature overshoot and the associated net negative emissions. In a publication in Environmental Research Letters, PBL researchers look into the economic considerations for such a decision; under which strategy is what option attractive? Having some overshoot can be attractive to avoid high near-term costs. However, the irreversibility of damages might be a reason to avoid overshoot.

Achieving the objectives of the Paris Climate Agreement requires a fast transition of the energy system. This leads to consequences for energy security, which is a central element of the energy strategy of many countries. Important dimensions of energy security are energy diversity and energy sovereignty. The main objective of this study is to assess how different strategies and climate objectives affect these dimensions. For this, the study presents a set of model-based mitigation scenarios that limit global warming to below 2 °C and 1.5 °C for 16 world regions. One conclusion is that energy supply diversity increases in deep mitigation scenarios in practically all regions, especially in India and China. There is also a substantial decrease in total energy trade in mitigation scenarios with a strong focus on intermittent renewables.

An accelerated, global roll-out of good practices in reducing greenhouse gas emissions may help to limit global warming to well below 2 °C, as agreed in the Paris Agreement on climate change. This is the main outcome of the newly developed Bridge scenario, which - if implemented effectively - will narrow the global emission gap between reductions announced in the Nationally Determined Contributions (NDCs) and those needed for a cost-optimal well below 2 °C scenario by two thirds, by 2030. After 2030, more comprehensive mitigation measures are needed, if we are to keep well below 2 °C within reach. Although a wide set of good practice policies is included in the scenario, these are insufficient - even if all would be jointly implemented - to put the world on track to limit global warming to 1.5 °C.