New Global Climate Scenarios: Highest Emissions Scenario Revised

The new high-emission scenario still leads to significant climate change, while uncertainties in the climate system mean that global temperature rise could even exceed 4°C by 2100. The fact that the low-emission pathways have become less favorable means that the Paris Agreement target of 1.5°C is no longer achievable without a temporary overshoot. 

New Global Climate Scenarios

In climate research, scenarios play a key role in exploring the potential long-term consequences of current choices and trends. This includes, for example, assessing the impacts of current policies, the potential risks of so-called worst-case scenarios, and determining what is needed to prevent extreme climate change. To develop these scenarios, global research groups must collaborate worldwide. For this reason, agreements are regularly made to jointly develop scenarios based on the most recent insights (within the framework of the Climate Modeling Intercomparison Project, CMIP).

The design of the scenarios for CMIP7 was published in April 2026 in Geoscientific Model Development by a group of scientists led by Detlef van Vuuren (PBL, Utrecht University). The set contains seven scenarios that will form the backbone of global climate research in the coming years. The scenarios are formulated in the form of emission pathways. In the coming years, they will be analyzed in detail to determine the consequences of climate change. There are a few notable changes: for example, the highest emissions scenario is now lower than that of the previous set of scenarios, but—on the other hand—the lowest scenario is actually less low than before.

Emissions in the highest-emission scenario are lower than in previous worst-case scenarios...

The highest-emission scenario serves as a basis for exploring the potential consequences of climate change if everything goes wrong. After all, it is important to ensure that we are also prepared for undesirable developments. This highest-emission scenario assumes a situation involving heavy reliance on fossil fuels. The highest-emission scenario now turns out to result in lower emissions than the previous highest-emission scenario (also known as RCP8.5 or SSP585). There are three main reasons for this. First, emissions in recent years have largely followed the medium scenario. This alone means that new projections are already lower. Additionally, the contribution of renewable energy has grown much faster than expected in recent years due to lower costs. As a result, the use of fossil fuels is not expected to increase very rapidly anymore. Finally, climate policy is being implemented, albeit still on a limited scale.

… but dangerous climate change remains a possibility

Although emissions in the highest CMIP7 scenario are lower this century than in the previous version (CMIP6), this does not mean that dangerous climate change has been averted. First of all, the expected warming in this scenario is still approximately 3.5°C above pre-industrial levels—a level at which very severe climate impacts are expected. Furthermore, we must take into account that the sensitivity of the climate system may be higher than our best estimate. In that case, the temperature rise could still easily exceed 4°C. Because global temperatures have risen more sharply than expected in recent years, such a significant temperature rise is certainly not out of the question. Furthermore, in the high-emissions scenario, temperatures will continue to rise even after 2100 and are expected to reach around 2150 the level previously projected for 2100.

There are no longer any scenarios that stay below 1.5°C

At the lower end of the range, various scenarios explore what is needed to prevent dangerous climate change and meet the goals of the Paris Agreement. Previously, it was still possible to design emission pathways that would keep warming around 1.5°C. Because emissions have risen further in recent years, that is no longer possible. Even the most optimistic scenarios will not return to around 1.5°C until the end of this century, following a significant overshoot of at least 0.2 to 0.3°C. This means that greater attention must be paid to climate impacts and climate adaptation. In addition to intensive emission reduction efforts, efforts will also need to focus on removing CO₂ from the atmosphere.

Further Research 

The climate scenarios will be further examined in climate studies worldwide in the coming years to determine the potential impacts of climate change. Ultimately, the emission scenarios, the results of climate models, and the estimates of climate impacts will be used in the IPCC report, which is expected to be published in 2028/2029.

Implications for the Netherlands

Dutch climate policy is based on the European ambition to be climate-neutral by 2050, in order to meet the obligations under the Paris Agreement. This goal remains unchanged by the new global scenarios. In the KEV, the PBL explores the consequences of current Dutch climate policy for the energy system and greenhouse gas emissions. There is currently no reason to assume scenarios other than those currently in use: both the lower and upper bounds of the KNMI’s recent climate scenarios remain possible and still represent the range of potential outcomes. The KNMI climate scenarios thus also form a robust basis for choices regarding a climate-resilient living environment, as described in a recently published adaptation study by the PBL. In the coming years, these scenarios will be re-evaluated based on the new IPCC reports.