There is clear evidence that technological change will be insufficient to meet UK and global climate goals on its own, leaving a vital role for consumer and business behaviour change.
Indeed, most measures to reach net-zero emissions by mid-century will require at least some behaviour change by the public.
This includes reducing car use, changing diets to eat less red meat and dairy, cutting waste and buying electric vehicles and heat pumps.
The scale of change is profound: limiting warming to 1.5C would mean reducing the average European carbon footprint from 7.5 tonnes of carbon dioxide equivalent (tCO2e) to 2.8tCO2e per person by 2030.
Behaviour change is also required to adapt to climate risks, such as flooding, drought and heat stress, our research shows.
This includes emergency and long-term behavioural responses, such as evacuation, buying insurance and installing equipment.
However, policies to deliver these behaviour changes are currently lacking in the UK.
In 2023, a House of Lords inquiry concluded that the government’s approach to enabling behaviour change for climate and environmental goals was “seriously inadequate”.
The Skidmore review of net-zero, also published in 2023, similarly concluded that more government action is needed to support behaviour change and advocated a public-engagement strategy to deliver this.
More recently, in a major review for the Climate Change Committee (CCC), my co-authors and I outlined what behavioural science can tell us about how to deliver effective climate policy.
We found that, in general, wider social or practical factors – such as norms, functionality and price – tend to be more influential for encouraging low-carbon behaviours than an individual’s knowledge, values and emotions.
How to change behaviour
There is a sizeable evidence base on how to deliver low-carbon and climate-resilient lifestyles and on changing behaviour in professional contexts.
Using literature searches and a call for evidence, identifying almost 400 sources in total, we examined evidence for what works to change behaviour within eight main areas:
- diet
- consumption
- aviation
- adaptation
- net-zero skills and careers
- business leaders and the transition to sustainability
- land use and farming
- policy acceptability
Numerous behavioural theories and models exist to explain and predict climate mitigation and adaptation actions.
Psychological theories, such as the theory of planned behaviour (TPB) and the value-belief-norm model (VBN) assume action is primarily driven by internal factors, such as attitudes, values and knowledge.
Specifically, the TPB states that behaviour results from intentions, which, in turn, are the outcome of attitudes, perceptions of social norms and ability.
The VBN sees behaviour as the outcome of a sequence of values, which informs beliefs and perceived responsibility for environmental problems, which shapes the moral obligation to act, leading to action.
Since the TPB includes perceived ability, acknowledging external social, physical and economic factors can limit or propel action. Research suggests it does better than the VBN at explaining higher-impact environmental behaviours, such as avoiding driving, than lower-impact behaviours that tend to be more within individuals’ control, such as recycling.
In contrast, sociological theories – such as social practice theory – tend to place more emphasis on the contextual drivers of action, such as physical infrastructure and social conventions.
Social practice theory sees practices – such as showering or cooking – as resulting from the interaction of physical and technological factors, social conventions and skills. These also see action as routine or habitual more often than intentional.
Integrative models also exist that draw on various theories to explain behaviour. One of the most commonly used is the COM-B model, which identifies capabilities, opportunities and motivations as the key drivers of behaviour.
Our review found that, in general, low-carbon and climate-resilient behaviours are driven by both internal and external factors, including:
- Individual knowledge, values and emotions.
- Social factors, such as norms and group identity.
- Practical factors, such as functionality, ease and price.
Of these various drivers, individual factors – such as knowledge – tend to be less influential in changing behaviour than wider social or practical factors.
Consequently, interventions targeting individual decision-making or motivation, such as information provision, tend to be less effective than interventions targeting the context of action. These interventions, such as regulations, incentives and infrastructure changes, typically make behaviour easy, attractive and normal – or even the default.
One review found that informational approaches, such as labelling or in-home displays, were on average only 3% effective. In contrast, “nudges” that adjust choice environments to make sustainable choices easier, but without coercion, were, on average, 25% effective.
These nudges could include locating recycling bins closer than regular waste bins or putting energy consumers on green tariffs (instead of fossil fuel tariffs) by default.
Individual-focused interventions, such as information provision (e.g. campaigns), are known as “downstream” measures, while context-focused interventions, such as nudges, economic measures and regulation, are “upstream” measures.
Despite evidence of its limited efficacy and tendency to exacerbate inequalities, there is a preference amongst policymakers for downstream over upstream interventions.
This is, in part, because the former is more easily experimentally tested and costed, but it is also due to power structures in government, political ideology and skills gaps.
Targeted and timely change
Beyond targeting upstream changes, our review also found that interventions are more effective when they are:
- Targeted – to the specific needs and abilities of different groups.
- Combined – that is, they include downstream and upstream approaches, as well as addressing the multiple behavioural drivers and barriers.
- Timed – to when habits are malleable, such as household renovation or relocation, or when business leaders or farmers are making key investment decisions. (In psychology, this is termed “habit discontinuity”.)
Public engagement is also important for effective behaviour change interventions to both foster acceptance and address contextual factors or constraints to efficacy, our research suggests.
Interventions to change behaviour that are imposed on people without consultation risk being rejected, as seen with the “Gilets Jaunes” in France and London’s Ultra low emission zone (Ulez) expansion protests. Bringing the public into decision-making from the outset to scope a problem and identify solutions is more likely to lead to fairer and more acceptable outcomes.
Climate assemblies and juries are examples of how this is increasingly being achieved. Engagement can also help communicate the need for and benefits of climate action and therefore promote policy acceptance.
From our research over the years at the Centre for Climate Change and Social Transformations (CAST), we know that different approaches work better depending on the sector.
For example, adaptation behaviour change requires a stronger focus on information provision than mitigation actions, since there is little public awareness of why or how to adapt to climate risks.
For transport, congestion charging and reallocating road space from cars to less polluting modes – such as pedestrianisation and low-traffic neighbourhoods – are amongst the most effective ways of cutting car use. Additionally, frequent flyer levies enjoy public support so may be a fair and effective way of curbing aviation growth.
But, in both cases, there is a need for “carrots” as well as “sticks”. Alternatives to driving and flying must also be convenient, affordable and attractive if people are to switch to these lower-carbon modes, our research found.
For diet change, communicating the various benefits of low-carbon diets and carbon labelling – for health and the environment – has some effect. However, our research suggests lowering the price of vegetarian options and making them more available – including the default option – is far more effective.
In one simple, but effective, study, researchers doubled the proportion of vegetarian meals available in canteens – from one-in-four, to two-in-four options. This led to increases in vegetarian meal sales of up to 79%.
But there are still gaps in the evidence base. Little is known, for example, about how to encourage people to adopt climate-resilient behaviours or to reduce flying. More generally, we found little evaluation of real-world interventions.
Removing barriers
Our review concludes with core recommendations for using behavioural science in climate policy. These include identifying behavioural targets – for example, based on carbon impact and feasibility – engaging with the public and combining, timing and tailoring interventions.
While there are evidence gaps, our research shows that much is already known about how to foster low-carbon, climate-resilient behaviour change.
Moreover, the public wants to play their part in tackling climate change. Public concern about climate change has not been reduced by Covid-19 or the cost-of-living crisis – and most people in the UK and around the world agree that individual behaviour change is needed.
We found that the government now needs to use these insights from behavioural science to remove the barriers to behaviour change. This, in turn, will help accelerate the net-zero transition and adapt to climate risks.
The post Guest post: How human behaviour shapes effective climate policies appeared first on Carbon Brief.
Guest post: How human behaviour shapes effective climate policies
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.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ) ruling on climate, according to the Guardian.
98
The number of nations that submitted their national reports on tackling nature loss to the UN on time – just half of the 196 countries that are part of the UN biodiversity treaty – according to analysis by Carbon Brief.
Latest climate research
- Sea levels are already “much higher than assumed” in most assessments of the threat posed by sea-level rise, due to “inadequate” modelling assumptions | Nature
- Accelerating human-caused global warming could see the Paris Agreement’s 1.5C limit crossed before 2030 | Geophysical Research Letters covered by Carbon Brief
- Future “super El Niño events” could “significantly lower” solar power generation due to a reduction in solar irradiance in key regions, such as California and east China | Communications Earth & Environment
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
UK greenhouse gas emissions in 2025 fell to 54% below 1990 levels, the baseline year for its legally binding climate goals, according to new Carbon Brief analysis. Over the same period, data from the World Bank shows that the UK’s economy has expanded by 95%, meaning that emissions have been decoupling from growth.
Spotlight
Bristol’s ‘pioneering’ community wind turbine
Following the recent launch of the UK government’s local power plan, Carbon Brief visits one of the country’s community-energy success stories.
The Lawrence Weston housing estate is set apart from the main city of Bristol, wedged between the tree-lined grounds