idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
International team publishes appeal in specialist journal
Various factors have caused warm and ice ages to alternate on Earth over the past thousands to millions of years. Researchers have been warning for decades that human influence could destabilize this system. But now the voices are getting louder. A team of researchers from Oregon State University (USA), including Thomas Westerhold from MARUM, is now calling for significant changes in climate policy in a commentary.
The article “The risk of a hothouse Earth trajectory” published today in the scientific journal One Earth is the result of an international collaboration led by William Ripple of Oregon State University that summarizes scientific findings on climate feedback loops and 16 tipping elements—subsystems of the Earth that can lose stability when critical temperature thresholds are exceeded. Their conclusion: Several components of the Earth system are much closer to destabilization than previously thought. This exposes the planet to an increased risk of a “hothouse” trajectory driven by feedback loops. These could exacerbate the consequences of global warming, according to the article.
“After a million years of alternating ice ages and warmer periods, the Earth's climate stabilized more than 11,000 years ago, enabling agriculture and complex societies,” said lead author Prof. William Ripple. “We are increasingly moving away from this stability and could be entering a phase of unprecedented climate change.”
These powerful changes could lead to a cascade of interactions between subsystems that would set the planet on a path to extreme warming and sea level rise, the article says —conditions that would be difficult to reverse even with deep emissions reductions on a human timescale.
Dr. Thomas Westerhold from MARUM – Center for Marine Environmental Sciences at the University of Bremen is one of the authors of the commentary. He and his colleagues also created the CENOGRID climate reference curve, which depicts the natural state and characteristics of climate from 66 million years of Earth's history.
“We might push the planet further than we realize. If we do not quickly turn away from the 'hothouse' trajectory, the global climate could shift to conditions not seen for tens of millions of years. Ecosystems are not adapted to these conditions, nor are they likely to be able to adapt due to the unprecedented speed of change caused by human activities. Climate records from the past 66 million years show that the Earth’s climate has fluctuated dramatically over millions of years. However, we are entering a new and uncertain phase due to rising anthropogenic greenhouse gas emissions and shrinking ice sheets. Current rates of change are unparalleled in the long-term history of Cenozoic climate,” says Thomas Westerhold, a MARUM scientist and co-author of the study.
The tipping elements include the ice sheets in Antarctica and Greenland, mountain glaciers, sea ice, boreal forests and permafrost, the Amazon rainforest, and the Atlantic Meridional Overturning Circulation (AMOC), a system of ocean currents that has a decisive influence on the global climate. Researchers note that nearly ten years after the Paris Agreement, which aimed to limit long-term average warming to 1.5 degrees Celsius above pre-industrial levels, global temperature rise has exceeded 1.5 degrees Celsius for 12 consecutive months — a period that has also seen extreme, deadly, and costly wildfires, floods, and other climate-related natural disasters.
To minimize the risk of a hothouse Earth trajectory, the scientists recommend strategies that embed climate resilience into government policy, alongside a socially just phase-out of fossil fuels. They also discuss the need for new approaches, such as coordinated global tipping-point monitoring and improved risk management plans.
MARUM produces fundamental scientific knowledge about the role of the ocean and the seafloor in the total Earth system. The dynamics of the oceans and the seabed significantly impact the entire Earth system through the interaction of geological, physical, biological and chemical processes. These influence both the climate and the global carbon cycle, resulting in the creation of unique biological systems. MARUM is committed to fundamental and unbiased research in the interests of society, the marine environment, and in accordance with the sustainability goals of the United Nations. It publishes its quality-assured scientific data to make it publicly available. MARUM informs the public about new discoveries in the marine environment and provides practical knowledge through its dialogue with society. MARUM cooperation with companies and industrial partners is carried out in accordance with its goal of protecting the marine environment.
Dr. Thomas Westerhold
MARUM – Center for Marine Environmental Sciences, University of Bremen
Phone: +49 421 218-65672
Email: twesterhold@marum.de
William J. Ripple, Christopher Wolf, Johan Rockström, Katherine Richardson, Nico Wunderling, Jillian W. Gregg, Thomas Westerhold, and Hans Joachim Schellnhuber: The risk of a hothouse Earth trajectory. One Earth 2026. DOI: https://doi.org/10.1016/j.oneear.2025.101565
https://www.marum.de/en/CENOGRID.html Press release CENOGRID
Information about the Earth's climate history is provided to researchers by deposited material (sedi ...
Source: U.Röhl
Copyright: MARUM – Center for Marine Environmental Sciences, University of Bremen; U. Röhl
Criteria of this press release:
Journalists
Environment / ecology, Geosciences, Oceanology / climate, Politics, Social studies
transregional, national
Cooperation agreements, Transfer of Science or Research
English
Information about the Earth's climate history is provided to researchers by deposited material (sedi ...
Source: U.Röhl
Copyright: MARUM – Center for Marine Environmental Sciences, University of Bremen; U. Röhl
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
