"Our health and climate research (Climate CATCH Lab, Melbourne School of Population and Global Health) team is currently in the Torres Strait Islands, guided by Sean Taylor, a University of Melbourne Professor in Indigenous Health, Director of Onemda and Murray Island man, talking with community members and health workers on the impacts of climate change and health and local health service provision in the region. Torres Strait Islander communities are already experiencing first-hand the impacts of heat stress, sea level rise and ocean warming on their physical, cultural and mental health.

Today's announcement by BOM is another urgent and timely reminder to Australian leaders that the least responsible for climate change are the most affected by its severe impacts. Aboriginal and Torres Strait Islander people should be the first heard on health and climate issues as they have 1000’s of years of ecological knowledge and adaptation experience and are best placed to protect and promote the health of their own people and place. Meetings in the Torres this week have revealed a need for more research and funding to help drive locally led community education and research into health adaptation."

"We have now passed the autumn predictability barrier, with an El Nino event now confirmed by the Australian Bureau of Meteorology.  This means that both the ocean and atmosphere in the Equatorial Pacific are interacting with one another in a sustained El Nino pattern. The current forecast of this El Nino is in the extreme to very extreme categories, driven by the extremely high sea surface temperatures in the Equatorial Pacific. At this stage, it is hard to predict the exact impact of this El Nino on Australia – no two El Ninos are the same; the strength of El Nino does not always predict the strength of the impacts; and Australia’s climate and weather is influenced by many other factors that may enhance or dampen the influence of El Nino.

Generally, an El Nino brings drier conditions during our winter and spring, which creates the background conditions for a hotter, drier summer. Whether or not this exact setup occurs depends on other climate and meteorological factors such as the Indian Ocean Dipole and the Southern Annular Mode. However, Australians should be vigilant about the summer that lies ahead, as the scales are now tipped towards drought conditions, longer and more severe heatwaves, and an increased risk of bushfire weather.

At the global scale, this El Nino has the strong potential to boost global average temperatures, on top of the ever-increasing warming due to human-induced climate change."

"The declaration of El Niño is not like flicking a switch - impacts have already appeared in some areas and will continue to emerge as we head into spring. These include an increased risk of heatwaves, drought, fire weather, and even coral bleaching. But El Niño is not our only climate driver. Climate change also increases the risk of all these impacts, as does a positive Indian Ocean Dipole (like El Niño, but in the Indian Ocean).

While a positive IOD may emerge in the spring, climate change has already loaded the dice for more extreme weather, with El Niño shortening the odds even further. While no two El Niños are ever exactly the same, they all now come with an added boost from 1.5°C of global warming. Managing the risk by using seasonal forecasts and listening to the scientists, rather than reacting to headlines, is important at a time when so many other factors are affecting our lives."

"The announcement by BOM of a severe El Niño immediately reminds me of the drought-like conditions in 1982-83 and 1997-98. This announcement is an area of concern as it is likely to impact water resources in remote areas that keep our farms moving and produce growing. Australia is likely to experience hotter and drier weather, particularly in the rural heartlands if it gets intense.  

We need to be prepared for such extreme climate variations that originate from changing ocean temperatures.  El Niño does not guarantee specific outcomes, but it shifts the odds. For Australia, this typically means an elevated risk of heatwaves, reduced winter–spring rainfall in key regions, and increased bushfire potential. It’s been a while since we had major bushfires, so this announcement is an area of concern. Over recent years the signalling has been mixed, and this is common when you are transitioning from a La Niña to an El Niño. Think tanks like CSIRO need to continue with their great work in seasonal prediction and climate modelling. Their research has helped us better understand and anticipate the risks, but uncertainty remains."

"It is interesting that the models predicted this El Niño so consistently and quite early this year. The large heat content in the Pacific subsurface was a strong indicator of this El Niño development, and the consistently negative Southern Oscillation Index shows strong coupling between the ocean and atmosphere, indicating that El Niño is developing and will persist at least until the end of the year, when the event usually peaks.

Globally, the decay of an El Niño event tends to increase global mean temperatures, meaning that there is a good chance a new record will be broken next year. But regionally, the impacts of El Niño event can differ depending on the region. For Australia, not necessarily a strong El Niño event means severe impacts on the ground. Past strong El Niño events such as 1997-98, 2015-16, 2024-25 had only weak or moderate impacts over Australia. While weaker El Niños with a warming peak in the Central Pacific seemed to have affected rainfall more consistently, contributing to droughts in 2002 and 2006 for example."

"We’ve been waiting a few years for El Niño to return. BoM’s announcement that it may finally be back – and with a vengeance – is, on the one hand, no great surprise. After all, this is a natural, large-scale oscillation of sea surface temperatures across the Pacific Ocean. However, on the other hand, climate change sets these natural oscillations on top of an increasing trend of warmer global temperatures. So what does this mean? For those of us at Adelaide University who research and teach concepts relating to climate change adaptation, we look to a few important design principles and the underlying science of our hydrological cycle.

All things being equal, warmer air can hold more moisture, and warmer water is easier to evaporate. So, processes involving evaporation (e.g. of the Pacific Ocean waters) get a boost in scale in an increasingly warmed world. This could play out in terms of longer dry periods (the warmed atmosphere has greater capacity to hold onto its moisture) and then in more intense rain events (all that extra moisture means that when it rains, it pours).

Climate change ‘adaptation’ has long been the poor relation to ‘mitigation’; for some, it is seen as giving up on the valiant quest of solving climate change. But that view is wrong for at least two reasons. First, we need to get better at adapting to variable and changing conditions (e.g. the impact of population and economic growth), irrespective of climate change. And second, we need to accept that even if the world doubles down on its Paris Agreement commitments, we’re headed for – at best – about a 2-degree world.

At Adelaide University, we teach adaptation in close concert with the principles of resilient design. This means building a deep understanding of how systems work, whose values are at stake, what makes them vulnerable, and what we can change to improve resilience. Faced with uncertain and potentially unprecedented weather extremes, resilient systems are those that build in modularity and redundancy, adopt smaller, decentralised scales, and prioritise diversity. These are the core principles that enhance our society’s ability to ‘weather the storm’ (or in the case of El Niño in Australia, the drought) and recover afterwards. However, at present, multiple aspects of our economy are systemically opposed to these principles: we favour concentration of capital and production in ever-larger, homogenised and centralised scales (evidenced in the massive concentration of wealth in a small number of individual people), and to keep this system growing, we tend to prioritise efficiency over redundancy.

Exactly what short-term future this El Niño will bring is still – quite literally – up in the air. However, the economies and infrastructure that survive into our longer-term, globally-warmed future will likely look very different to what we see today."

"While El Niño is a natural part of Australia’s climate variability, its characteristics are changing with climate change. Extreme El Niño–Southern Oscillation (ENSO) events are projected to increase with climate change. The Bureau of Meteorology’s declaration that we are now officially in an El Niño, and its forecast that it is likely to be strong to very strong, is an important warning for all Australians.

Amongst the many impacts of El Niño in Australia is its impact on our health. It can produce drought, heatwaves, and bushfires, which directly or indirectly threaten our health and sometimes our lives. While preparing for this particular El Niño and adapting to the increasing frequency of such events is vital, mitigation of climate change through rapid and deep reductions in greenhouse gas emissions here and elsewhere should be the nation’s top priority. Our health and lives depend on it."

"While cautious in their correlation, the BOM have suggested that Australia is likely to have hotter and drier Spring and Autumn, which may increase bushfire risk and, of course, impact agriculture and have long-term impacts on water storage for urban use.

The measured approach is commendable; however, from a public policy perspective, the language could stymie action. I think Australia needs a more comprehensive acknowledgement of laws and policies of the new norm of increased climate variability, and this could be facilitated by a definition of climate change. Climate change is recognised through scientific and international legal frameworks (notably the UNFCCC and IPCC), and regulated domestically through statutes addressing emissions reduction, adaptation, and climate impacts rather than through a single unified statutory definition."

"The El Niño declared by the BOM will potentially bring with it warmer and drier weather. This may mean that we experience heatwaves, higher fire risk, reduced water allocations or new drought declarations, but the precise impact remains uncertain. Impacts of the El Niño will be experienced differently in different parts of the country, depending on the preceding environmental conditions as summer approaches and how long the system lasts. We need to prepare, but not panic.

In Victoria, the major water storages are at similar levels as the same time last year, and soil moisture is average for this time of the year. We need to be comfortable with the uncertainty that what happens in the next three to six months in terms of snowfall, rainfall, and temperature will determine our summer experience. We need to prepare and make plans based on the best available information.

We need to listen to the experts, such as BOM, Agriculture Victoria, the CFA and prepare plans for our safety and the integrity of our communities and economy based on the most timely and reliable information available. Climate change challenges our resilience. Being prepared, making plans on the best available and reliable information, will aid our resilience."

"El Niño is now not just a possibility anymore, but a reality and in full swing. We can observe warmer water off the South American coast and weaker winds along the equatorial Pacific, anticipating stirring up weather around the world. El Niño works like a gigantic washing machine that suddenly spins the other way around. By this, huge amounts of energy and with-it atmospheric moisture are getting redistributed to parts of the world that usually see very little or a lot of these. This can cause droughts on the one hand side and floods or extreme rainfall on another.

As far as we can remember, El Niño events have occurred and are part of our natural world. However, it’s the first time a strong El Niño event is happening in an already 1.4°C warmer world. We simply have no precedent, and uncertainty is large around El Niño potential impacts. For Australia, we expect warmer and drier conditions but fortunately the strength of the El Niño will not dictate the impacts. In the past, some strong El Nino had very little overall impact on the weather in Australia, but we certainly fear those events that did."