It has been a very warm summer in the UK. By mid-July, we’d had our third heat wave of 2025, with temperatures here in Liverpool topping 30°C. That followed the heatwave at the start of July, when Kent hit 35.8°C – just four and a half degrees short of the hottest temperature ever recorded in the UK (Lincolnshire hit 40.3°C in 2022). The UK’s first heatwave of the year, in mid June, caused the deaths of an estimated 600 people in England and Wales.
This isn’t normal. Or, at least, it wasn’t normal – a new report in the International Journal of Climatology highlighted how normalised extreme temperatures are becoming in the UK, as a result of climate change. As the Met Office explained, “the last three years have been in the UK’s top five warmest on record, with 2024 the fourth warmest year in records dating back to 1884”.
Last year was the warmest May on record, and the warmest spring on record. February 2024 was the second warmest ever recorded. We had a top-five warmest winter. For parts of the UK, six of the 10 warmest years on record have come in the last decade – based on records stretching back to the 1780s.
It’s not just the high temperatures that are an issue, it is the increasing extremity of temperatures. Temperatures haven’t been rising steadily at the same rate evenly across the year – we are now far more likely to suffer extreme highs and extreme lows. Compared to the average daily temperatures from 1961-1990, the number of days that are 5°C above that baseline have doubled in the last decade. The number that are 10°C above baseline in that time has quadrupled – we now average more than three days per year that are 10°C higher than the 30-year baseline.
It isn’t even just the heat; it’s also the extreme rainfall events, both in terms of average daily rainfall and extreme flooding events. For the decade from 2015 to 2024, the winter half-year (October-March) was 16% wetter than the baseline 30 year period from 1961-1990. The previous winter half-year, from October 2023 to March 2024, was the wettest in all of recorded history, with records stretching back to 1767. Six of the 10 wettest winter half-years for England and Wales have been in the 21st century.
All of this should be a real concern, even to those who remember the famous Summer of 1976, when the UK had a heatwave that lasted 16 consecutive days – longer than the this year’s heatwaves combined. Even accounting for those 16 days of extreme heat, June 1976 was cooler on average than June 2025. This was not normal, and now it is.
The UK is not prepared for extreme heat. While air conditioning is relatively commonplace in hotels, shops, cinemas, and other large indoor spaces, it is not routinely installed in UK homes. Historically, there hasn’t been a compelling need for domestic AC, but that may be changing, with industry reports suggesting around 20% by 2022 of UK homes had some form of air conditioning by 2020, up from 3% in 2011. In France, which has also seen extreme heatwaves, home AC coverage rose from 14% in 2016 to 25% in 2020; it’s hard to imagine the last four years didn’t see a further rise.
However, air conditioning is not an optimal solution to our increasing temperatures, because AC units consume a lot of power. According to the US Department of Energy, 12% of energy consumption in homes goes on running the air con, and a 2019 report from the International Energy Authority suggests that widespread global AC adoption would contribute 2 billion tonnes of CO2 annually. As the world heats, the go-to solution to our overheated houses will only exacerbate the situation.
Energy wastage is a serious climate change issue. Take, for example, electronic advertising – each large-sized 62 square metre screen electronic billboard consumes annually enough energy to run 32 households. The estimated 14,500 advertising screens across the country could be powering more than 50,000 homes in total. Even if those screens are using truly renewable energy – rather than buying dubious carbon offset credits – they’re still wasting renewable resources that could be better served powering those households, or hospitals, or anywhere else where the consumption is essential. In any sensible world where we took climate change seriously, an easy win would be to turn every one of those superfluous screens off.
Political leadership is needed
The kind of large-scale changes that would substantially limit our carbon emissions and prevent energy waste require a strong political will, and that’s hard to achieve when there are well-funded climate change denialist lobby groups like the Global Warming Policy Foundation and the Institute for Economic Affairs, and while there are politicians who believe they know better than the science.
Unfortunately, there are more than a few in that latter group. We learned that recently, as the Reform UK councillors in charge of my hometown council of County Durham scrapped their net zero pledge, in spite of opposition from cross-party councillors and campaigners. That followed a council meeting in Nottinghamshire, where senior Reform UK councillor Bert Bingham, paused proceedings to explain that climate change is a hoax, and he should know because “he has worked in sustainability for 25 years”. Bingham told the council,
“The statistics are manipulated. I’ve followed it over decades, there’s lots of science out there, but at the moment it seems to be as in a lot of matters with Covid, if you follow the money, you find the science or the pseudoscience.”
Bingham might not want to be so keen to encourage people to follow the money to find the pseudoscience: party, Reform UK, accepted £2.3m in donations from climate deniers and fossil-fuel interest groups before the 2024 election, accounting for 92% of the party’s donations. It’s maybe no surprise, then, that just one in three Reform voters believe in human-caused climate change. Clearly, those fossil fuel interest groups got what they paid for.
Close behind Reform UK – as the Tories are getting used to being – the Conservatives have abandoned their climate change targets, claiming that the aim of Net Zero by 2050 is “arbitrary”, “not based on science”, and a product of the Intergovernmental Panel on Climate Change being “biased”. And while Labour’s Ed Miliband has been doing an admirable job in advocating for solutions to climate change, even telling parliament that politicians who reject net zero policies are “betraying future generations”, we might not be able to rely on policy changes and mass movements to cut carbon emissions and prevent an even greater climate disaster.
A technical solution?
So, what can be done? In April of this year, the UK government greenlit small-scale experiments into geoengineering (much to the chagrin of chemtrail conspiracists across the land). The Advanced Research and Invention Agency (Aria) announced a £56.8m programme looking to “explore – under rigorous oversight – whether any climate cooling approaches that have been proposed as potential options to delay or avert [climate] tipping points could ever be feasible, scalable, and safe”.
The project involves five proposed outdoor experiments. One of the projects will explore the efficacy of rethickening arctic sea ice – which makes some sense, because we know that arctic ice is melting, and we know that as the ice coverage shrinks, the big white surfaces that would otherwise reflect light and heat are replaced by dark watery surfaces that absorb heat, which will speed up the melting of the remaining ice and the raising of sea water levels.
Another of the proposed projects studies how milligram quantities of mineral dusts age in the stratosphere – but before the chemtrail conspiracy theorists get too panicked, these chemicals wouldn’t be released, they’d be kept for analysis, it’s just a pilot scheme to understand what happens to them at that altitude.
The other projects are more likely to draw the ire of the chemtrail busters, however, because they focus on exploring the effects of seawater spray and electric charges on cloud reflectivity. The idea being that, like the ice shelves, clouds reflect heat from the sun so it doesn’t get absorbed by land or water, and if you can make the existing clouds more reflective – either by changing their water composition, or running an electric charge through them – you might be able to mitigate some of the warming.
This might all sound risky, but ARIA do make a point of stating that the experiments “will only go ahead after a period of meaningful public engagement with local communities, and will all be subject to oversight by the programme’s independent oversight committee” and that “all ARIA-funded experiments will be time-bound, limited in size and scale, and their effects will dissipate within 24 hours or be fully reversible.”
In the extensive FAQ on their website, they make it clear that these experiments don’t involve any chemicals that are harmful to humans or animals, won’t affect the growing of crops, and won’t change the weather or the seasons. Also, they make it clear that they are not trying to block out the sun. However, those FAQs did little to reassure anyone who was worried about geoengineering and chemtrails, with a petition on the Parliament website, titled, “Make all forms of ‘geo-engineering’ affecting the environment illegal”, gathering 160,000 signatures:
We want all forms of geo-engineering to be illegal in the UK. We do not want any use of technologies to intervene in the Earth’s natural systems.
We think there is a potential for this to negatively impact humanity, flora and fauna in the future. It has previously been said that Greenhouse Gas Removal (GGR) is essential to meet climate targets. We believe that this, and all other forms of geo-engineering, should be made illegal in the UK.
The petition received a response from the government, who made clear that:
the wider consequences of Solar Radiation Modification (SRM) are poorly understood, with significant uncertainty around the possible risks and impacts of deployment. As such, the government’s position is that it is not deploying SRM and has no plans in place to do so.
Reasonable criticism
It isn’t just the chemtrail conspiracy community that has issues with these pilot investigations – opposition has been far broader, and more mainstream. Talking to the Guardian, Mary Church, from the Center for International Environmental Law, argued:
Solar geoengineering is inherently unpredictable and risks breaking further an already broken climate system. Conducting small-scale experiments risks normalising highly controversial theories and accelerating technological development, creating a slippery slope toward full-scale deployment.
While some of the theories may appear sound, the climate is a hugely complicated system – or collection of systems – and any change to it might be wildly unpredictable. According to the BBC, studies have demonstrated that Solar Radiation Modification “could cause strong warming high above the tropics, changing large-scale weather patterns, warming the polar regions and altering rainfall patterns around the world”. Brightening cloud cover in south-west Africa off the coast of Namibia, while well intentioned, could cause a drought in South America, which could in turn starve the Amazon rainforest.
Equally, while geoengineering may be capable of bringing down global average temperatures, there’s nothing to say that such a reduction would happen evenly – it may result in even more extreme climate issues in specific areas of the world. It’s very complicated, and we simply don’t know what could happen as a result.
Meanwhile, there are solutions that we do know would work, that are not beset by such uncertainty, and these form the other strain of criticism ARIA has received: spending our time chasing geoengineering solutions can be a huge distraction from the essential work of decarbonisation, carbon neutrality, and reducing emissions. By introducing a technological Hail Mary, we could essentially send the message that it’s fine to carry on as we are, because science is going to come along and solve it all. If and when those proposed technical solutions fail, it will be too late to actually take the mitigating action we need.
This criticism is particularly pertinent, given that the Big Tech and FinTech industries have invested heavily into geoengineering research. Arguably, a technical deus ex machina would mean heavy polluting industries wouldn’t have to tackle their own very significant contributions to the climate crisis. Why turn those big advertising screens off and stop them beaming commercial messaging into unsuspecting eyes if you’ve got a magical machine that zaps out special clouds to keep the heat under control? Or, more cynically, why turn those screens off – or deal with your data centres and your mass wastage – if you can tick the green credentials box on a form by saying you’re investing in the solution? As long as the cost of funding the research is less than the cost of tidying up your carbon mess, you’re in profit.
For what it’s worth, ARIA does actually acknowledge those criticism. They explain:
There is no substitute for decarbonisation, which is the only sustainable way to lower the chances of such tipping points and their effects from occurring.
Our current warming trajectory already makes a number of tipping points distinctly possible over the next century.
If faced with a climate tipping point, our understanding of the options available remains limited. This knowledge gap has driven increased interest in whether there are approaches (also known as “climate interventions”) that could actively reduce temperatures globally or regionally over shorter timescales.
Yet, in the absence of robust data, we currently have little understanding of whether such interventions are scientifically feasible, and what their full range of impacts might be. This programme aims to gather such data so that we can better understand these approaches and their potential effects.
ARIA maintain that they are only running small-scale trials that are time bound and heavily regulated, with no plan to actually deploy them. However, if they come back with promising results, what’s to stop billionaires with commercial biases like Elon Musk from spinning up the scheme at scale, safe in the knowledge that they’re essentially beyond the regulatory powers of any country in the world? It’s a colossal risk, and one that could even be existential.
Is geoengineering the answer?
While there is much uncertainty, one thing is abundantly clear: we cannot just wait to be saved by tech solutions like these – Solar Radiation Modification, Carbon Capture and Storage, even even mass tree-planting schemes (that often end up generating more carbon than they save). They’re unproven, complex, and potentially highly risky. The solution has to be to reduce emissions, to push for policies that promote carbon neutrality, and to push for politicians that will prioritise it.
The idea of seeding the atmosphere with large amounts of chemicals that shouldn’t be there, and that will change global temperatures and weather systems in ways we cannot predict or control, is obviously folly.
However, that is precisely what we have been doing for over a century, with our out-of-control carbon emissions. Climate change is the result of geoengineering, but rather than a small scale trial, it was a mass experiment we’ve ran with no controls, no oversight, and no way of stopping.
Whether we like it or not, those climate crisis tipping points are coming, if they’re not already here. We cannot afford to be complacent, and we cannot afford to let the likes of the Global Warming Policy Foundation, the Institute for Economic Affairs, and the other wealthy fossil fuel interest groups – nor the politicians they’ve bought and paid for – dissuade us from taking the kind of radical action we need to avert this crisis. But if we don’t, if we fail to decarbonise and reduce our emissions, there may well come a time where the potential benefits of those risky geoengineering experiments are far safer than continuing our inaction.
Let’s hope we never get to that point.
