Prof Louise Heathwaite CBE became the executive chair of the National Environment Research Council (NERC), the UK’s main agency for funding natural science research, in March 2024.
She was the chair of the Science Advisory Council of the UK’s Department for Environment, Food and Rural Affairs (Defra) and has previously served as chief scientific adviser to the Scottish Government for Rural Affairs, Food and Environment. She is a leading hydrochemist.
- On realising human’s environmental impact: “When the ozone hole was being discussed. So I knew from a long, long time ago that we were doing damage.”
- On funding climate research: “You can’t look at climate research just as climate research. It’s a nexus. It’s thinking about climate change, the implications for biodiversity loss and other changes like pollution.”
- On funding solar geoengineering: “A few years ago, I think this council and many others would not have gone into solar geoengineering in any sense. We’re getting closer and closer to 2050. That starts you looking for more extreme routes.”
- On Brexit’s impact on UK research: “I think that led to some breakage of communication and links with people working in Europe particularly.”
- On reaching net-zero in the farming sector: “So far, that vision hasn’t been much beyond ‘we’re going to plant trees everywhere, and cows are bad’.”
- On transforming land-use in the UK: “We do need it, but it’s hard to see who’s going to really have the oversight.”
- On lack of public attention on biodiversity loss compared to climate change: “I think pollution and biodiversity loss are lagging behind as it’s much more complex to understand that system.”
Carbon Brief: You have a long standing career as a hydrologist and a pollution expert, when did you first become aware that humans were having a large impact on the natural world through pollution and agriculture?
Prof Louise Heathwaite: Before I went to university – well before I went to university. At school I studied maths, economics and geography and put it together in that sort of sense. Then I went on to do an environmental science degree at the University of East Anglia. At that point, there were only two places you could do environmental science, UEA or Lancaster. Lancaster was far too close to home for me [Heathwaite is from Leeds]. UEA were doing some really cutting edge science. That’s when the ozone hole was just being discussed. So I knew from a long, long time ago that we were doing damage. So it’s been with me all that time. And that progression with working with the Natural Environment Research Council started at that point. I went from doing a degree to doing a PhD at Bristol and that was funded by NERC.
CB: What was your PhD in?
LH: I was looking at peatlands, wetland hydrology and hydrochemistry. I was looking at the impact of [peatland] drainage on water quality. The place I was working was the first SSSI [site of special scientific interest] ever declared in the country. It was a place called West Sedgemoor in the Somerset Levels. It was a real interesting challenge there, looking at the difference between what the [wildlife charity] RSPB wanted to do to protect that site versus the farming community, who wanted to actually farm that site, and how you get some sort of shared understanding. It was really fascinating. And underneath that there were some real chemistry questions to answer as to why the river was getting polluted and what the issues were. And it wasn’t anything to do with the farming community at all. It was to do with the geology of the site. Really interesting.
CB: This year, you became the executive chair of NERC. What are the key areas of climate research that NERC is looking to fund?
My perspective is you can’t look at climate research just as climate research. I think there are three parts to this, it’s a nexus. It’s thinking about climate change, the implications for biodiversity loss and other changes like pollution. So I always argue you’ve got to think of it through that three-way nexus. The direction of travel I’m trying to take NERC through in terms of our forward look is developing thinking that I’m starting to call “beyond carbon”. So when you talk to communities like the financial industry, what they’re looking for when they want to understand biodiversity loss is another metric, like carbon, that can tell them how to deal with the problems. [We need to] get to the realisation that, for biodiversity loss, there is no single metric. And a lot of what the climate change drivers are doing are causing feedback loops, which damage biodiversity, create other sorts of challenges, and how do we understand that? So there’s a whole load of work to do in that sort of space. So that’s one bit where climate change is a real driver. The other bit is around national security and health. Your floods, your droughts, risk for wildfires, risk for temperature and heat and what that does to people. That’s another area.
Then the third area you might think will be quite unusual for NERC, which is starting to look at what we’re calling “responsible innovation”. So NERC has just got a call out around solar radiation management. Now, a few years ago, I think this council and many others would not have gone into solar geoengineering in any sense. But the position we’re getting into now is we’re getting closer and closer to 2030 and to 2050 and trying to get to things like net-zero. That starts you looking for more extreme routes. I think it’s important that a research council tries to understand what the implications are of anybody following those extreme routes. I need to be clear, we’re not doing out-of-door experiments, it’s more around modelling and maybe some laboratory work to try and understand that. But if we don’t understand solar radiation management, or we don’t understand the sort of interventions you might do in the oceans, then we’re not going to be able to advise on the implications. And, with the Natural Environment Research Council, we’ve got everything at our fingertips, really, because we do deep ocean to upper atmosphere. We do pole to pole. We do air, land, water. And that captures the global capacity. And so actually addressing those climate change challenges sits right in our remit, at a very difficult time, really.
CB: How has NERC research funding been impacted by Brexit? Does NERC have all the resources it needs at the moment?
Brexit or everything else after Brexit? We’ve had Brexit, then we have Covid, and then we had Ukraine and inflation and all of those things. From a Brexit context, and this is a personal view, I think that led to some breakage of communication and links with people working in Europe particularly. Now we’re part of Horizon again [the EU’s €96bn research programme], I can see that coming back, which is absolutely fantastic, it’s really important. I think also within NERC, all of those issues that I just mentioned have also led us to perhaps start looking [at] more UK-wide, rather than global and international science. That’s something I want to change. That international science is absolutely critical, particularly as we’ve got many of our scientists working with the IPCC [Intergovernmental Panel on Climate Change] and IPBES [Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services]. And we’ve got the new UN Environment Programme around pollution and waste. So those three areas I mentioned before, we’ve now got intergovernmental panels which are actually looking at them. I think of our opportunity as to how we bring them together and think about it as a system.
CB: You recently stood down as the chair of the Science Advisory Council for Defra. What did it entail, how often were you briefing ministers and what kind of information were you sharing with them?
LH: So this was the highest level advisory committee within Defra, but part of our role was very particularly to help support and advise the chief scientific adviser [CSA], so that they were getting the best sort of advice. So the way that that worked was to basically take challenges from across Defra and [answer questions such as] are we doing this right? What’s your advice? How could we do this sort of thing? And get that [answered] by a wide range of people on the committee. [This was] to actually ensure two things: that the right sort of questions were being asked of the science and the right sort of evidence was being gathered, and that evidence was being used effectively. So the route was really to make sure that the CSA had a group of “critical friends”, in a sense, but also was [well] informed. Briefing ministers was the CSA’s job. Acting as a science advisory committee [and] actually making sure that the CSA and others in Defra were actually being coherent in their messages around the science – it was fascinating. But I’d been on Defra’s Science Advisory Council before, so that was really exciting. I’ve been a chief scientific adviser in the Scottish Government for Rural Affairs, food and environment before, so that fitted really well with that role. But it’s an important entity providing that sort of independent advice, that critical friend bit, is always important.
CB: Farming and land use have been a weak spot in UK climate plans, and now agriculture is a bigger emitter than power plants, for example. What do you think is needed to help the farming sector get to net-zero?
LH: I guess let’s start with the end point, getting to net-zero by 2050. It’s going to be a challenge to ever get to [actual] zero [emissions]. And what does getting to the “net” in net-zero mean? We need to have that national security of still being able to turn the lights on. I think that’s important. By setting targets and target dates, this is the bit I mentioned about geoengineering, it tends to get more and more desperate measures because you’ve got a target. I tend to think of it more as a transition. How do we transition, both in terms of behaviours, but also in terms of the science and the interventions we can put in to actually get to those sorts of places? So that seems to me to be really, really important and how we actually capture that moving forward is critical.
CB: So how do we transition the farming sector?
LH: That is always going to be a challenge because you’ve got two things. One, I think we need to look at farming and the farming community and landowners as being part of the solution, not the problem. Think of them as custodians of land and of the environment. Therefore, you start having a different conversation, which isn’t, “this is wrong, having cows and sheep is wrong”. But: “How do we actually get to a better place where we can have a shared understanding of what the environment’s about? What alternative livelihoods do people have?” Even down to evaluating whether we pay the right sort of amount for the meat we want to eat. So if people were prepared to pay more but eat less of it, that might actually change the economics of how farming might work. But none of that works if you go to the supermarket and buy something that’s been shipped in from some other country, either. So I think it’s a conversation, a shared conversation, about what the vision is for the future. And I think, so far, that vision hasn’t been much beyond “we’re going to plant trees everywhere, and cows are bad”. You’ve got to turn it into “we’ve got a fabulous landscape, we’ve got a very dense population, we want to do all these other things with our land, how can we actually have a conversation to get us to the right place?” And that’s not going to be easy, but what I’m seeing is now much more cross-government thinking about how to get there.
If you actually mapped out all the policies that we want to achieve from our land, we haven’t got enough area, nowhere near enough area, to actually achieve them. So we’ve got to think about the nature of the interventions and what we achieve. It’s a really exciting space. From my perspective, coming from where I came from as a scientist, understanding how those changes might impact on other parts of the system. So like the freshwater environment, which is always the bucket in which all the problems end, and then we pass that on to the marine environment, and we pass it up to the atmospheric environment, how can we actually get a more sustainable solution there? So it’s an opportunity, But if you turn it into a problem, all you do is back people into a corner.
CB: The new Labour government has come in, and it has a lot on its in-tray when it comes to food, land in nature, including a land-use framework and its international nature pledge under the UN biodiversity convention. Which of these documents would you like to see being published soon, and what sort of details do you think will be critical for those documents?
LH: Big question, massive question. I’ll probably answer this a bit tangentially because it’s really a matter of how you can achieve what you can achieve. This government has got a very strong focus on delivery for people quickly. And there are some quite exciting and quite interesting projects around clean energy by 2030, as an example. So what does that mean for things like land use that we’ve just been talking about, biodiversity and all of those things? Is it a really good pledge, but the ones around the land-use strategy are really, really challenging. Because, say, clean energy for 2030, if we can make that work, we’ll need to make sure we get the transition mechanisms in place to move energy around from generation points to to where it actually needs to be delivered. If we can do that for energy, we can probably do that for land. So we do need it, but it’s hard to see who’s going to really have the oversight. And everybody wants a piece of this pie. But all the things that this new government is wanting can’t be achieved without some joined-up thinking. So I put that quite high.
I also think making clear our commitment to work in the international space [is important]. My council, the National Environmental Research Council, is the one that thinks at long timescales, large scales, global. So actually having that international presence and keeping our science cutting edge and curiosity driven is just so important in that sort of space. So I’d be articulating that through the new government that the research and innovation part is really, really critical, because that’s where you’ve actually got that curiosity driving new thinking, but you’ve also got the innovation which takes that new thinking and now converts it into something useful. Some of it’s shovel-ready now, but actually, some of it’s going to take time to actually get us there.
CB: So, finally, we touched on this before, but the issues of pollution and biodiversity loss tend to receive less attention at a national and international level than climate change. Why do you think that is and how can that be addressed?
LH: I think it’s only that climate change has been thought of as being doable – because it’s carbon, and we’ve got that single metric – and therefore business and industry can buy into that and they can think about how to build it into their business models. The reason I think pollution and biodiversity loss are lagging behind is it’s much more complex to understand that system and we’re only getting together now with the science to actually help us do that and develop those metrics. But there is no single metric to say we can understand biodiversity loss. It’s going to take some more systematic thinking. And one of the really good things I think about where NERC is now placed within UKRI [UK Research and Innovation, a government department] is that we’ve got that cross-research council thinking, which allows you to pull from all the various disciplines to get a solution.
The post The Carbon Brief Interview: Prof Louise Heathwaite appeared first on Carbon Brief.
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
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