The Climate Group is hosting Climate Week NYC from September 20th to the 27th, 2026 obviously in New York City, United States of America. The theme this year is energy, the impact and the action that is needed to address climate change. The week long event has various sessions, side events and round tables covering six streams -
American Innovation and Abundance: This stream is promoted as being a first-in-kind approach to provide a focal point to elevate and explore the next generation of US leadership in innovation, investment and resiliance. Worldwide, this sentiment might considered to be unduly optimistic considering ongoing political activities in the US in respect of climate change.
Energy: This stream is considering how as demand rises from electrification and AI, the challenge is no longer just generating clean power but delivering it reliably, affordably at scale and pace. For the US this is challenging given the continuing use of fossil fuels despite also having nuclear power and renewable energy generation.
Food: Food security must be treated with the same urgency as energy security. The focus of this stream is finding scaleable solutions from regenenerative agriculture to protein diversification and tackling food waste. Some elements of this problem are solveable with many steps (such as seed banks and crop genetics research) already in progress.
Leadership and Green Growth: According to the conference papers "..driving the transition at pace requires bold leadership, smart strategy, and collaborative action". A true statement but one at odds with US Federal Government direction.
Nature and Health: Perhaps stating the obvious, the conference sees "nature and human health as deeply interconnected, underpinning resilient economies and societies". The objective of this conference stream is "find solutions that deliver measureable benefits for both people and societies". A admirable goal if somewhat blue sky.
Transport and Industry: Noting that transport and heavy industry are at the heart of the global emissions challenge, the conference lays down the direction "from electification and clean fuels to green construction and circular supply chains, we must reimagine how we move goods and people, build and manufacture at scale''. Nicely expressed but can they produce the workable results ?
The website for the event can be accessed at this link: climate week nyc
The world is set to miss the 1.5°C global warming target, and plans are underway for UN climate talks in the Pacific and Turkey.
Climate mitigation – reducing or preventing greenhouse emissions – was once treated as the only legitimate response to global warming. In comparison, climate adaptation – trying to adjust to global warming – was seen as a form of defeatism, or worse, hubris.
But that taboo has long since lifted: our collective failure to prevent climate change means adaptation is now an essential part of climate policy.
Similarly, attitudes to actively removing carbon dioxide from the atmosphere have undergone an evolution. While there are reasons to doubt whether carbon removal can work at scale, Australia’s “net zero emissions” plans rely on these interventions.
Now, the taboo surrounding another controversial form of climate intervention – solar radiation modification
(SRM) – appears to be lifting.
What is solar radiation modification?
SRM refers to large-scale technological interventions that reflect a small amount of sunlight back into space, thereby lowering global temperatures. Increasingly called the more benign term “climate stabilisation”, the proposed methods include space mirrors – satellites equipped with large reflective surfaces – and cloud brightening, where microscopic particles are sprayed into clouds to make them more reflective.
The most commonly discussed SRM technique is stratospheric aerosol injection (SAI) – the release of particles into the upper atmosphere to recreate the cooling effects observed following volcanic eruptions.
SRM is so controversial it’s sometimes called the “Voldemort of climate policy”. While it could reduce global temperatures, it does not limit carbon emissions, and the ecological effects of deployment are uncertain.
Some critics are worried a potential techno-fix will deter mitigation efforts. Others point out the risks of “termination shock”: once implemented, ending SRM would cause abrupt temperature rise. Scientific research suggests the strong warming experienced since 2023 is likely a case of inadvertent termination shock. When new fuel regulations reduced sulphur dioxide emissions from international shipping, the rapid warming that followed revealed this pollution had, incidentally, been cooling the planet.
At present, SRM inhabits an international and domestic policy vacuum. Many scholars advocate for a ban on both research and deployment, saying these technologies “play God” with nature. We argue a ban on research is no longer tenable.
Why challenge the taboo?
The case for taking SRM seriously does not usually rest on enthusiasm for the technologies, but on global warming’s grim reality. We are approaching planetary tipping points such as significant polar sea ice retreat, the death of the Amazon rainforest and widespread coral reef loss. SRM advocates say it should be viewed as a complement, not an alternative, to mitigation: a means of limiting the extent and duration of temperature overshoot while decarbonisation continues.
Government appetite for this approach is limited and patchy. When the UN Environment Assembly discussed a Swiss proposal for SRM research in 2024, countries could not agree even on whether and how to regulate research in this area. Countries such as Japan and Saudi Arabia pushed for ongoing research, while vulnerable Pacific and African countries argued against any language that risked endorsing the practice.
Nowhere is the politics of SRM more volatile than the United States. One group of Republicans reject the climate change “hoax” but is so convinced SRM is already happening that many Republican states have criminalised it. Some think tanks advocate SRM as a way to defend “American Weather Sovereignty”. NASA has an exploratory program investigating space-based reflective dust clouds. For now, the Trump administration has not chosen a side, but it’s easy to imagine a future administration unilaterally blocking, or implementing, SRM.
If we don’t challenge the SRM taboo, self-interested actors are poised to fill the policy vacuum. Elon Musk has recently spoken out in favour of SRM, while ventures such as the US-Israeli startup Stardust are pursuing research without public oversight.
What is Australia’s position?
Australia has no policy on SRM research or deployment, but federal government funds have supported related research into local interventions, including the Reef Restoration and Adaptation Program (RRAP). This trialled the world’s most respected marine cloud brightening research over the Great Barrier Reef.
Existing environmental and climate law might regulate risks posed by small-scale research, but does not consider the larger risks of eventual deployment. With the exception of some ad hoc efforts, SRM research is not subject to any dedicated ethics framework.
The planetary scale of SRM impacts means we urgently need research to consider the geographic distribution of benefits and harms from any deployment, and the security implications of unilateral deployment by any state or private actor.
What should Australia do?
As a trusted middle power, Australia is well positioned to help lead discussions on the future of SRM. At a minimum, Australia should assess the potential impacts of various options on Australia’s climate, agricultural production and natural environment, and develop a public position on research.
Waiting until a foreign government or well-resourced private actor forces the issue would leave Australia reacting to decisions made elsewhere. Instead, we should prepare for the surprises a fast-moving, under-governed field is likely to produce.
As temperature overshoot becomes an inevitability, SRM is emerging as a new element of international climate policy whether we like it or not. We do not argue anyone should deploy SRM, but that we should break the taboo and enable responsible scientific research and public deliberation.
The United Nations Environment Assembly this week considered a resolution on solar radiation modification, which refers to controversial technologies intended to mask the heating effect of greenhouse gases by reflecting some sunlight back to space.
Proponents argue the technologies will limit the effects of climate change. In reality, this type of “geoengineering” risks further destabilising an already deeply disturbed climate system. What’s more, its full impacts cannot be known until after deployment.
The draft resolution initially called for the convening of an expert group to examine the benefits and risks of solar radiation modification. The motion was withdrawn on Thursday after no consensus could be reached on the controversial topic.
A notable development was a call from some Global South countries for “non-use” of solar radiation modification. We strongly support this position. Human-caused climate change is already one planetary-scale experiment too many – we don’t need another.
A risky business
In some circles, solar geoengineering is gaining prominence as a response to the climate crisis. However, research has consistently identified potential risks posed by the technologies such as:
the infringement of human rights across generations – including, but not limited to, passing on huge risks to generations that will come after us.
Here, we discuss several examples of solar radiation modification which exemplify the threats posed by these technologies. These are also depicted in the graphic below.
An infographic showing the effects of solar engineering methods.Authors provided
A load of hot air
In April 2022, an American startup company released two weather balloons into the air from Mexico. The experiment was conducted without approval from Mexican authorities.
The intent was to cool the atmosphere by deflecting sunlight. The resulting reduction in warming would be sold for profit as “cooling credits” to those wanting to offset greenhouse gas pollution.
Once started, this stratospheric aerosol injection would need to be carried out continually for at least a century to achieve the desired cooling effect. Stopping prematurely would lead to an unprecedented rise in global temperatures far outpacing extreme climate change scenarios.
Injecting aerosols into the atmosphere may lead to more droughts.Shutterstock
Heads in the clouds
Another solar geoengineering technology, known as marine cloud brightening, seeks to make low-lying clouds more reflective by spraying microscopic seawater droplets into the air. Since 2017, trials have been underway on the Great Barrier Reef.
The project is tiny in scale, and involves pumping seawater onto a boat and spraying it from nozzles towards the sky. The project leader says the mist-generating machine would need to be scaled up by a factor of ten, to about 3,000 nozzles, to brighten nearby clouds by 30%.
After years of trials, the project has not yet produced peer-reviewed empirical evidence that cloud brightening could reduce sea surface temperatures or protect corals from bleaching.
The Great Barrier Reef is the size of Italy. Scaling up attempts at cloud brightening would require up to 1,000 machines on boats, all pumping and spraying vast amounts of seawater for months during summer. Even if it worked, the operation is hardly, as its proponents claim, “environmentally benign”.
The technology’s effects remain unclear. For the Great Barrier Reef, less sunlight and lower temperatures could alter water movement and mixing, harming marine life. Marine life may also be killed by pumps or negatively affected by the additional noise pollution. And on land, marine cloud brightening may lead to altered rainfall patterns and increased salinity, damaging agriculture.
More broadly, 101 governments last year agreed to a statement describing marine-based geoengineering, including cloud brightening, as having “the potential for deleterious effects that are widespread, long-lasting or severe”.
A cloud brightening field trip in 2021 (Southern Cross University)
Balls, bubbles and foams
The Arctic Ice Project involves spreading a layer of tiny glass spheres over large regions of sea ice to brighten its surface and halt ice loss.
Another proposed intervention is spraying the ocean with microbubbles or sea foam to make the surface more reflective. This would introduce large concentrations of chemicals to stabilise bubbles or foam at the sea surface, posing significant risk to marine life, ecosystem function and fisheries.
No more distractions
Some scientists investigating solar geoengineering discuss the need for “exit ramps” – the termination of research once a proposed intervention is deemed to be technically infeasible, too risky or socially unacceptable. We believe this point has already been reached.
Since 2022, more than 500 scientists from 61 countries have signed an open letter calling for an international non-use agreement on solar geoengineering. Aside from the types of risks discussed above, the letter said the speculative technologies detract from the urgent need to cut global emissions, and that no global governance system exists to fairly and effectively regulate their deployment.
Calls for outdoor experimentation of the technologies are misguided and detract energy and resources from what we need to do today: phase out fossil fuels and accelerate a just transition worldwide.
Climate change is the greatest challenge facing humanity, and global responses have been woefully inadequate. Humanity must not pursue dangerous distractions that do nothing to tackle the root causes of climate change, come with incalculable risk, and will likely further delay climate action.
It might sound like science fiction, but “marine cloud brightening” is being seriously considered as a way to shield parts of the ocean from extreme heat.
We’re using water canons to spray seawater into the sky. This causes brighter, whiter clouds to form. These low marine clouds reflect sunlight away from the ocean’s surface, protecting the marine life below from the worst of climate change.
Australia’s Reef Restoration and Adaptation Program – a collaboration between several universities, CSIRO and the Australian Institute of Marine Science – is exploring whether cloud brightening could reduce coral bleaching. As an oceanographer and engineer I lead the program’s research into cooling and shading techniques.
We started exploring cloud brightening after the mass bleaching event in 2016. First, we needed to develop and test the underlying technologies in the lab. Then we began pilot testing in the central Great Barrier Reef near Townsville during January 2020. After several iterations we have now moved beyond “proof of concept” to investigating the response of the clouds themselves.
The Cloud Brightening Field Trip of 2021 (Southern Cross University)
A bright idea
British cloud physicist John Latham originally proposed cloud brightening in 1990 as a way to control global warming by altering Earth’s energy balance. He calculated that brightening clouds across the most susceptible regions of the world’s oceans could counteract the global warming caused by a doubling of preindustrial atmospheric carbon dioxide. That’s a level likely to be reached by the year 2060.
Recently, scientists have begun to consider regional rather than global application of cloud brightening. Could brightening clouds directly over the Great Barrier Reef for a few months reduce coral bleaching during a marine heat wave?
Modelling studies are encouraging and suggest it could delay the expected decline in coral cover. This could buy valuable time for the reef while the world transitions away from fossil fuels.
Lowering the heat stress on the ecosystem would produce other benefits when combined with other reef interventions – such as improved control of invasive crown of thorns starfish and planting of corals with increased heat tolerance.
But these studies also show there’s a limit to what can be achieved. Long-term benefits are only possible if the cloud brightening activity occurs alongside aggressive emissions reductions.
Cloud brightening does have risks as well as benefits, but the prospect of intermittent regional use is very different to large-scale “solar geo-engineering” proposals for shading and cooling the whole planet.
We expect the regional effect will be short-lived and reversible, which is reassuring. The technology must be operated continuously to modify clouds and could be stopped at any time. The sea salt particles sprayed in the process typically only persist in the atmosphere for one to several days.
Southern Cross University’s aerosol and cloud microphysics aircraft operating over the Southern Great Barrier Reef.Southern Cross University
How do you brighten a cloud?
A warm cloud (as opposed to an ice cloud) is a collection of small water droplets floating in the air.
A cloud of many small droplets is brighter than one with fewer large droplets – even if both clouds contain the same amount of water overall.
Every droplet begins with the condensation of water vapour around a nucleus, which can be almost any kind of tiny particle suspended in air.
Typically, in the lower atmosphere over land there are thousands to tens of thousands of these tiny particles suspended in every cubic centimetre of air. We call these airborne particles “aerosols”.
Aerosols may be natural such as dust, sea salt, pollen, ash and sulphates. Or they may come from human activity such as burning fossil fuels or vegetation, manufacturing, vehicle exhaust and aerosol spray cans.
When a cloud forms under these conditions, water vapour is forced to condense around fewer nuclei, creating larger droplets and fewer of them. Large droplets reflect less light for the same volume of cloud water.
To brighten such clouds, we can spray large quantities of microscopic seawater droplets into the air. This process of atomising seawater mimics the generation of sea salt aerosols by wind and waves in the ocean. If these are incorporated into a cloud and create extra droplets, the cloud will be brightened.
The latest cloud brightening generator (V model) in action.Southern Cross University
Testing the theory
Although scientists have researched cloud brightening for more than 30 years, no one had ever directly tested the theory. In Australia, we have now developed technology to a point where we are starting to measure the response of the clouds.
We are beginning such tests with the support and permission of Traditional Owners, who have sustainably managed their Sea Country for tens of thousands of years.
Our research program involves more than 15 research institutions and has multiple levels of governance and oversight.
Not so far-fetched
Most people probably don’t realise we are already inadvertently brightening the clouds. The Intergovernmental Panel on Climate Change estimates humanity’s unintentional release of aerosols offsets around 30% of the warming effect due to greenhouse gases.
Sulphates in ship exhaust are such a potent source of aerosols for droplet formation, the passage of ships leaves cloud trails called ship tracks.
When the International Maritime Organisation introduced new rules limiting the sulphur content of marine fuels, the number and extent of ship tracks drastically reduced, especially in the Northern Hemisphere. A recent study even suggests the devastating heat wave that swept the Northern Hemisphere earlier this year was worsened by the absence of ship tracks.
The world-first research we are conducting in Australia aims to determine if we could harness the clouds in an effective, environmentally responsible and socially acceptable manner for the future conservation of one of our most precious ecosystems.
ESG, the abbreviation for environmental, social and governance (as in corporate governance) has become the latest buzz method for performance measurement and reporting for large corporate entities. It covers a myriad of activities (for example, climate change, biodiversity, pollution, risk management, diversity, employee engagement and so on) and there are a plethora of ways of measuring ESG and weighting various scores with the result that there is not an overall single rating determined. Different ESG audit companies use different methods that can and do lead to different ESG ratings being given to the same client company. Confusing it can be.
ESG is not directly the same as environmental sustainability as ESG involves measuring against a set of criteria which are focussed on company process and practices. Sustainability in contrast is focussed on outcomes. Highly polluting and environmentally damaging industries would use ESG as a risk management tool to ensure that they have best practice processes to mitigate pollution, avoid accidents, reduce the need for expensive regulatory requirements/compliance and hence the risk of costly litigation. Sustainability in contrast is focussed on the impact of the company's activities on people and the environment including the sustainability of the services and products.
In one respect ESG has evolved as a result of the strong movement to ethical investing and increasing demands from funding bodies (such as banks), investors and consumers for greater corporate responsibility to be demonstrated. Such demands also focus attention on company's social licence to operate in a range of industries that may have high impacts on communities. Where corporations do not demonstrate responsibility, the social licence to operate is placed at risk.
The climate change issue is as complex a topic with global community engagement and communication as much as it is about the science and technological solutions to address it. While there is strong support for action in Europe, the Pacific and many parts of Asia, there continues to be very divided opinions in the United States and Australia.
The Yale Program on Climate Change Communication has provided valuable insights into the communication challenge with climate change and the US population. Flowing from research and survey work started in 2009, the Yale program has demonstrated that there are six distinct and unique audiences in the US. These six audiences have very different levels of engagement on the climate change issue due to varying psychology, culture, risk perception, attitudes and political affiliation.
The Alarmed are fully convinced of the reality and seriousness of climate change and are already taking individual, consumer and political action to address it. The Concerned are also convinced about global warming but are not engaged with it personally.
The three other groups being the Cautious, the Disengaged, and the Doubtful represent different stages of understanding and acceptance that climate change is a problem. None of these groups are actively engaged with the issue.
The real concern are the Dismissive who are very sure that climate change is not happening and are actively involved as opponents of a national effort to reduce greenhouse gas emissions.
The distribution and size of the six groups are shown in Diagrams 1 and 2.
There are signs that perceptions are changing and that public opinion in the United States is slowly shifting to greater engagement and concern about climate change. Comparing Diagram 1 (above) with Diagram (2) below which covers a 12 month period from 2018-2019, a discernible movement to greater alarm can be detected.
Diagram 2
From an Australian point of view, similar categories of community engagement would almost certainly be identified here with key political leaders being within the Dismissive group.
COP21 has reached the end of its negotiations and the host nation, France, has submitted the draft text for voting by the 195 nations. At around 20 pages this is significantly shorter than the previous 29 pages and contains a number of critical elements -
the draft climate agreement would seek to limit global warming well below 2 degrees Centigrade aiming for around 1.5 degrees Centigrade,
a system of five-yearly reviews and monitoring of each nation's progress is proposed,
climate financing for developing nations of at least $100b by 2020 would be provided.
Despite the relative logic of these core elements there remains considerable barriers to achieving full agreement and compliance with the multitude of nations whose support is essential.
The latest round of climate change negotiations are soon to start later this month running from 30 November to early December 2015. The twenty-first
session of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change and the eleventh session of
the Conference of the Parties serving as the meeting of the Parties to the
Kyoto Protocol (CMP) will take place from 30 November to 11 December 2015, in
Paris, France. While there has been some level of doubt as to the likelihood of achieving agreement, research by the United Nations has found that considerable action has been undertaken across a range of functions by most of the parties to the Framework Convention. The chances of a Copenhagen-style COP failure are significantly less than previous years with widespread acceptance of the target of a temperature increase of no greater than 2 degrees Celsius from the pre-industrial baseline.Yet many doubts exist on the capacity of various countries to deliver fully on their stated intentions. A significant number of countries are still reliant on fossil fuels for energy generation with the resultant use of coal and emissions of CO2.
The United Nations Framework Convention on Climate Change (UNFCCC) took centre stage this week when the 18th session of the Conference of
the Parties to the UNFCCC to the Kyoto Protocol opened on Monday,
26 November 2012. COP18, as it is commonly referred, continues for two weeks until Friday, 7 December in Doha, Qatar, and expectations of major developments in various negotiations to mitigate the impact of climate change are very low. Ever since the debacle at the Copenhagen conference in 2009 (COP15), the reality of the quite substantial divisions between various groups of nations has been clearly apparent. The issue remains what can possibly provide a future step beyond the Kyoto protocol than to have some form of agreement such as Kyoto II. However genuine agreement remains elusive even with recent reports such as the World Bank warning of the a serious risk of a 4 degree Celsius rise in temperature actually occuring. The research findings of the United Nations Environment Programme (UNEP) at COP18 that the permafrost in the Northern Hemisphere is melting should provide an incentive for an agreement to be reached. But will there be any such agreement ?
