Research clarifies record-late monsoon onset, aiding northern Australian communities

Institute of Atmospheric Physics, Chinese Academy of Sciences

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A monsoon burst over Darwin.

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Credit: Chris Garth

Every year, Australia experiences a summer monsoon characterized by the reversal of winds, heavy rainfall and flooding. In 2024-2025 however, the Australian summer monsoon (ASM) was the latest on record since measurements began in 1957.

The monsoon's timely arrival is critical for Northern Australia. It dictates water security for communities, drives pasture growth for the vital cattle industry and signals the end of the high bushfire risk period.

The start of the ASM is defined by the change in prevailing dry southeasterly trade winds that occur most of the year to moist northwesterly winds that dominate during the wet season. These winds are measured above the city of Darwin, which is located in the northernmost part of Australia, and is often the first place in Australia to experience the onset of monsoonal conditions each season, usually around Christmas and the New Year.

Despite favorable large-scale climate conditions that would usually support an earlier onset, such as a La Niña-like state in the Pacific Ocean, record ocean warmth and strong ocean convection in December, the ASM onset occurred on 7 February 2025, more than five weeks later than usual and more than two weeks later than the previous record set in 1972-1973.

To better understand the reasons for the delayed ASM in the summer of 2024-2025, an international research group led by scientists from the University of Southern Queensland investigated monsoon criteria and local weather conditions that may have affected the onset of the ASM.

The team published their study on January 29 in Advances in Atmospheric Sciences as part of a special issue organized by the WMO's World Climate Research Programme monsoon panel.

“We… wanted to determine whether this record-late onset was a genuine feature of the broader monsoon system or a result of the local wind conditions at Darwin. To understand this further, we compared numerous monsoon onset definitions across northern Australia and investigated the atmospheric processes that occurred before and during the onset period,” said Tim Cowan, Associate Professor in the Centre for Applied Climate Sciences at the University of Southern Queensland in Toowoomba, Australia and first author of the research paper.

To determine if the late ASM was due to a true delay in the monsoon season or isolated conditions in Darwin, the research team applied multiple ASM- and rainy season (RS)-onset definitions and analyzed the atmospheric and oceanic conditions during the pre-monsoon and onset periods in Darwin and the surrounding area.

Importantly, the researchers observed that the conditions in Darwin during the summer of 2024-2025 did not necessarily reflect other parts of Australia. “The record-late ASM onset in 2024/25 was not entirely representative of the broader monsoon conditions across all of northern Australia but only specific to local wind conditions over Darwin. Other onset definitions showed much earlier onsets than the official ASM wind definition for Darwin, especially those that describe the onset of rainfall,” said Rajashree Naha, research fellow at the Centre for Applied Climate Sciences at the University of Southern Queensland in Toowoomba and co-author of the research paper.

The data suggests that local weather variability over Darwin prevented the upper-level winds from switching to easterlies, despite the presence of strong westerlies in December.

The team hopes their research will benefit weather communication with the general public. “Often people (and the media) confuse the official monsoon onset, based on local winds, with the onset of the first monsoonal rains. The release of our new study provides a great opportunity to improve the messaging around the monsoon arrival and what these impacts are on local communities,” said Cowan.

Ultimately, the research team emphasizes their work isn't just about wind definitions. It's about ensuring that communities who depend on the monsoon receive clear, actionable information. The team hopes the new study could help improve preparedness across the north Australia.

As the 2025-2026 wet season unfolds, communities and forecasters are once again watching Darwin's winds closely—a reminder of how critical clear and accurate monsoon onset information is for northern Australia each and every year.

Hanh Nguyen, Sugata Narsey, Matthew C. Wheeler and Chris Lucas from the Bureau of Meteorology in Melbourne, Australia; Hanna Heidemann from the University of Melbourne School of Geography, Earth and Atmospheric Sciences in Parkville, Australia and the Centre for Applied Climate Sciences at the University of Southern Queensland, in Toowoomba, Australia; Corey Robinson from the School of Earth, Atmosphere and Environment at Monash University in Clayton, Australia and the Australian Research Council Centre of Excellence for 21st Century Weather in Clayton, Australia; Andrew G. Marshall from the Centre for Applied Climate Sciences at the University of Southern Queensland in Toowoomba, Australia and the Bureau of Meteorology in Hobart, Australia; and Lin Wang from the Center for Monsoon System Research at the Institute of Atmospheric Physics (IAP) in the Chinese Academy of Sciences (CAS) in Beijing, China also contributed to this research.

This work was supported by Meat & Livestock Australia, the Queensland Government through the Drought and Climate Adaptation Program, and the University of Southern Queensland through the Northern Australia Climate Program (NACP).

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Journal

Advances in Atmospheric Sciences

DOI

10.1007/s00376-025-5352-2 

Article Title

Why Was the Official Australian Monsoon Onset Unusually Late in 2024/25?

Article Publication Date

29-Jan-2026

 

How to motivate collective action on climate

One of the most effective ways to move individuals to act together on climate involves showing them how past collective actions have delivered structural change, a new study finds

Stanford University

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What does it take to spur individuals to act as a group with a shared purpose on climate change? According to a new Stanford-led study, the key is to show them how collective actions on climate have made a difference and often generate good vibes for participants. 

A decade after nearly 200 world leaders agreed in Paris to limit climate change, solar power has become the fastest-growing source of new electricity and dozens of countries have cut emissions while growing their economies. Globally, emissions from burning fossil fuels – the largest contributor to human-caused climate change – have slowed but not declined. 

“Structural change is truly what’s needed, but you can’t get structural change without individuals demanding it,” said Madalina Vlasceanu, an assistant professor of environmental social sciences in the Stanford Doerr School of Sustainability and senior author of the study, which appears Jan. 27 in the journal PNAS Nexus.

Vlasceanu and her team recruited more than 30,000 U.S. residents to test 17 different psychology-backed interventions intended to encourage people to join a collective climate action, such as participating in a public demonstration or writing to a representative. The interventions featured videos, images, text, and interactive elements, such as prompts to write a short reflection.

The top intervention provided examples of past collective efforts on climate that have influenced public policy, showed a short video conveying the energy at climate marches, and invited participants to recall or imagine forming friendships through climate action. The intervention closed with a message that joining collective actions can boost happiness and build social connections.

“People really engage in collective action if they are made to feel that it will matter, that it will have an impact and create structural change, while also benefiting them personally,” said lead study author Danielle Goldwert, a PhD student at New York University.

Optimism over anger

After the intervention phase, participants had the opportunity to take or commit to any of three action types. The researchers grouped actions such as signing up for a climate organization’s newsletter, sharing a video calling for collective climate action, or committing to attend climate-related demonstrations into a “public awareness” bucket. They grouped political actions such as signing a petition, writing a letter to a representative, or committing to support “climate-friendly” politicians into a second bucket. Finally, they grouped financial actions such as donating to climate organizations or committing to divest from banks that invest in fossil fuels. 

The most effective intervention overall – combining evidence of impact with social and emotional benefits – increased willingness to take public awareness actions by 30% and political actions by nearly 14%. Moral framing around purity and sanctity, emphasizing preservation of America’s pristine places and sacred national monuments, raised financial advocacy by about 13%. Interventions that relied on negative emotions like guilt and anger were less effective on average. 

The researchers were surprised to find virtually no change in participants’ commitments to taking collective climate action when interventions emphasized co-benefits of addressing climate change, such as how reducing pollution improves human health or investing in renewable energy leads to economic growth. 

“It feels intuitive that co-benefits should motivate people – why wouldn’t we solve climate change if it’s also going to solve health care and the economy? But we found null results in all categories when using this strategy,” Vlasceanu said. 

Motivating long-term change

In previous research, Vlasceanu has examined what motivates people to take individual climate actions, such as recycling or eating less red meat. While there is some overlap, the primary motivating factors for individual actions center around how difficult they are to implement. The new study provides evidence that collective climate action may be more motivated by knowledge of how effective the action can be. 

“When you want to do something about climate and it’s personal, you primarily do the things that are easy,” Vlasceanu said. “When you want to do something about climate and it’s collective, you definitely want to do the thing that will work.”

The interventions were fairly short – 10-15 minutes each – so the researchers expect they will only create short-term changes in participant behavior. But Vlasceanu and her team are working on creating and testing longer interventions. With support from the Doerr School of Sustainability’s Discovery Grant program, Vlasceanu and co-author Sara Constantino, assistant professor of environmental social sciences, are developing a documentary based on the principles of the most successful interventions. They intend to follow participants over several years to understand effects on behavior over time. 

They’ve also created an interactive web tool to help other researchers explore their data. The tool allows users to see which interventions worked best for particular age groups, income levels, political ideologies, and other categories. Vlasceanu hopes it will be useful for her fellow scientists as well as for groups looking to increase climate engagement. 

“Climate change is a collective problem and individual solutions alone are inadequate for addressing it,” Vlasceanu said. “This could help practitioners get a flavor of what kinds of messages resonate with their target audience to inspire collective action.”

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Vlasceanu is also an assistant professor (by courtesy) of organizational behavior at Stanford Graduate School of Business and a faculty fellow at Stanford Impact Labs and the Stanford Center for Affective Science.

Stanford co-authors include Robb Willer, professor of sociology in the School of Humanities and Sciences; Christoph Semken, a former postdoctoral scholar at the Stanford Environmental and Energy Policy Analysis Center who is now an assistant professor at the University of Toronto; Yash Patel, a PhD student in environmental social sciences in the Doerr School of Sustainability; and Ke Fang, a PhD student in psychology in the School of Humanities and Sciences.

Additional co-authors are affiliated with New York University, Princeton University, University of Amsterdam, University of Trento, University of Cambridge, University of Konstanz, Yale University, Copenhagen Business School, University of Canterbury, Global Citizen, Columbia University, London School of Economics and Political Science, University of Queensland, University of California San Diego, Science Po Paris, Slovak Academy of Sciences, University of Wisconsin-Platteville, University of California Los Angeles, Centre National de la Recherche Scientifique, European University Institute, Franhoufer Institute for Systems and Innovation Research, Leiden University, Erasmus University Rotterdam, Northeastern University, Polish Academy of Sciences, University of California Santa Barbara, Pomona College, University of Bologna, Rochester Institute of Technology, José Luiz Egydio Setúbal Foundation, Boston College, Saarland University, University of Colorado Boulder, and University of North Carolina Wilmington.  

This work was funded by the National Science Foundation, a Grantham Research Institute PhD Scholarship, a Cambridge Humanities Research Grant, the Keynes Fund, a CRASSH Research Grant, the Carlsberg Foundation, and an ERC Consolidator Grant. 

 

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Journal

PNAS Nexus

DOI

10.1093/pnasnexus/pgaf400 

Article Title

A Megastudy of Behavioral Interventions to Catalyze Public, Political, and Financial Climate Advocacy

Article Publication Date

27-Jan-2026

 

New Boston University study identifies CTE as cause of dementia

Researchers found those with advanced CTE had four times increased odds for having dementia

Boston University School of Medicine

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Boston–The largest study of its kind from the Boston University CTE Center reveals that chronic traumatic encephalopathy (CTE) should be recognized as a new cause of dementia.

The research, published online today in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, studied 614 brain donors that had been exposed to repetitive head impacts, primarily contact sport athletes. By isolating 366 brain donors that had CTE alone, meaning they had CTE in the absence of any other progressive brain disease, compared to 248 donors without CTE, researchers found those with the most advanced form of CTE had a four times increased odds for having dementia. The four times odds are similar to the strength of the relationship between dementia and advanced Alzheimer’s disease pathology, which is the leading cause of dementia.

“This study provides evidence of a robust association between CTE and dementia as well as cognitive symptoms, supporting our suspicions of CTE being a possible cause of dementia,” said corresponding and senior author Michael Alosco, PhD, associate professor neurology at Boston University Chobanian & Avedisian School of Medicine and co-director of clinical research at the BU CTE Center. “Establishing that cognitive symptoms and dementia are outcomes of CTE moves us closer to being able to accurately detect and diagnose CTE during life, which is urgently needed.”

Dementia is a clinical syndrome that refers to impairments in thinking and memory in addition to trouble with performing tasks of daily living like driving and managing finances. Alzheimer’s disease is the leading cause but there are several other progressive brain diseases listed as causes of dementia that are collectively referred to as Alzheimer’s disease related dementias (ADRD). With this new study, the authors argue that CTE should now also be formally considered an ADRD.

The study also reveals that dementia due to CTE is often misdiagnosed during life as Alzheimer’s disease, or not diagnosed at all. Among those who received a dementia diagnosis during life from a healthcare provider, 40 percent were told they had Alzheimer’s disease despite showing no evidence of Alzheimer’s disease at autopsy. An additional 38% were told the causes of their loved one’s dementia was “unknown” or could not be specified.

In addition, this study addressed the controversial viewpoint expressed by some clinicians and researchers that CTE has no clinical symptoms. As recently as 2022, clinicians and researchers affiliated with the Concussion in Sport Group meeting, which was underwritten by international professional sports organizations, claimed, “It is not known whether CTE causes specific neurological or psychiatric problems.”

“There is a viewpoint out there that CTE is a benign brain disease; this is the opposite of the experience of most patients and families,” said Alosco. “Evidence from this study shows CTE has a significant impact on people’s lives, and now we need to accelerate efforts to distinguish CTE from Alzheimer’s disease and other causes of dementia during life.”

As expected, the study did not find associations with dementia or cognition for low-stage CTE.

The authors note that prospective studies with objective assessments and age-matched controls are needed to validate their findings.

The study was supported by the National Institute of Neurological Disorders and Stroke, National Institute on Aging, Department of Veterans Affairs, and the Nick and Lynn Buoniconti Foundation.

About the BU CTE Center

The BU CTE Center is an independent academic research center at the Boston University Avedisian & Chobanian School of Medicine. It conducts pathological, clinical and molecular research on CTE and other long-term consequences of repetitive brain trauma in athletes and military personnel. For people considering brain donation, click here. To support its research, click here. 

 

 

 

 

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Journal

Alzheimer’s & Dementia

DOI

10.1002/alz.71032 

Method of Research

Data/statistical analysis

Subject of Research

Human tissue samples

Article Title

CTE neuropathology alone is associated with dementia and cognitive symptoms

Article Publication Date

27-Jan-2026

 

Nitrate in drinking water linked to increased dementia risk while nitrate from vegetables is linked to a lower risk, researchers find  

Edith Cowan University

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New research from Edith Cowan University (ECU) and the Danish Cancer Research Institute (DCRI) investigated the association between the intake of nitrate and nitrite from a wide range of different sources, and the associated risk of dementia. 

Dementia is a complex disease shaped by both genetics and lifestyle, and Post-Doctoral Research Fellow at ECU’s Nutrition & Health Innovation Research Institute (NHIRI) and the DCRI, Dr Nicola Bondonno said dietary factors could also be important.  

The research, which investigated the association between source-specific nitrate and nitrite intake and incident and early-onset dementia, followed more than 54,000 Danish adults for up to 27 years and found that the source of nitrate was of critical importance in a diet. 

The researchers found that people who ate more nitrate from vegetables had a lower risk of developing dementia, while those who consumed more nitrate and nitrite from animal foods, processed meats, and drinking water, had a higher risk of dementia. 

ECU Associate Professor Catherine Bondonno said that nitrate intake from vegetables has been linked with a lower risk of dementia, which is thought to be a result of the conversion of nitrate to nitric oxide in the body. 

“When we eat nitrate-rich vegetables, we are also eating vitamins and antioxidants which are thought to help nitrate form the beneficial compound, nitric oxide, while blocking it from forming N-nitrosamines which are carcinogenic and potentially damaging to the brain. 

“Unlike vegetables, animal-based foods don't contain these antioxidants. In addition, meat also contains compounds such as heme iron which may actually increase the formation of N-nitrosamines. We think this is why nitrate from different sources has opposite effects on brain health, but we need laboratory studies to confirm exactly what's happening,” she said.  

This is the first time that nitrate from drinking water has been linked to higher risks of dementia. The study found that participants exposed to drinking-water nitrate at levels below the current regulatory limits, had a higher rate of dementia, however, Dr Bondonno stressed that this was only one study, and more research was required.  

“Water doesn't contain antioxidants that can block formation of N-nitrosamines. Without these protective compounds, nitrate in drinking water may form N-nitrosamines in the body,” she said.  

In Denmark and the EU, the limit for nitrate in groundwater and drinking water is set at 50 mg/L, but the researchers observed a higher risk for drinking water containing as low as 5 mg of nitrate per litre. 

“Importantly, our results do not mean that people should stop drinking water. The increase in risk at an individual level is very small, and drinking water is much better for your health than sugary drinks like juices and soft drinks. However, our findings do suggest that regulatory agencies should re-examine current limits and better understand how long-term, low-level exposure affects brain health.”  

She simultaneously emphasises that this is an observational study, which cannot establish that nitrate directly causes dementia. The results must therefore be confirmed in other studies, and it cannot be ruled out that other factors in participants' diets or lifestyles contribute to the association. 

Dr Bondonno said the take-home results from the study is fairly simple: people who consume more nitrate from vegetables, equating to around one cup a day of baby spinach, had a lower risk of dementia. 

On the other hand, people who consumed more nitrate from animal-based foods, particularly red and processed meat, had a higher risk.  

“Eating more vegetables and less red meat and processed meat is a sensible approach based on our findings and decades of other research on diet and health,” she added.  

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Journal

Alzheimer s & Dementia

DOI

10.1002/alz.70995 

Article Title

Source-specific nitrate intake and incident dementia in the Danish Diet, Cancer and Health Study