Climate science is a key tool for governments tasked with preparing citizens and infrastructure for the impacts of global warming.
But translating climate information into policy planning is no easy feat.
In a recent study, published in Climate Policy, we explore how climate science is – and is not – being used in national-level adaptation planning in 16 countries in southern Africa.
We find that there is often a disconnect between analysis of climate data, assessments of climate impacts and proposed adaptation options.
Adaptation plans are also often failing to look at the full range of plausible climate futures.
As well as identifying key barriers in how climate projections are being used, we offer some recommendations for how climate science could be more effectively integrated into adaptation plans, including enhancing collaboration between scientists and adaptation planners and clarifying what is meant by scientific uncertainty.
Climate adaptation
Climate adaptation can take place at many levels – from someone painting their roof white to keep their home cooler, for example, all the way up to the construction of large-scale flood defences.
Adaptation measures can include sustainable agricultural methods, including agroforestry; water collection and storage, such as dams; and public services, such as early warning systems and impact-based weather warnings.
Adaptation can be a response to current conditions, or a long-term plan based on projections of future climate change.
In many countries in southern Africa, governments face pressing economic challenges and deep structural inequalities, in addition to pronounced impacts from weather events. Long-term planning is not always at the top of priority list.
Yet, awareness of future climate might be crucial to avoid maladaptation – when adaptation interventions have negative consequences which increases vulnerability to climate change. (For example, a measure designed to increase irrigation to improve agricultural yields in a region projected to become drier, leading to increased water insecurity.)
National communications
To get a picture of how climate science is being factored into country-level adaptation planning, we analyse information in “national communications” submitted by countries to the UN, as well as conduct interviews with experts, government officials and climate scientists.
National communications are reports where countries provide updates on their vulnerability to climate change, as well as an inventory of their greenhouse gas emissions and the steps they are taking towards emissions reduction and adaptation.
Our study looks at national communications submitted by the 16 countries that form the Southern African Development Community (SADC). These are Angola, Botswana, Comoros, Democratic Republic of Congo, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namibia, Seychelles, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe.
Developing countries are required to submit national communications every four years to the UN Framework Convention on Climate Change (UNFCCC).
All southern African countries featured in the analysis have submitted at least one national communication. (Namibia and Zimbabwe have submitted five each.)
However, the UNFCCC’s guidance on how to assess climate impacts and vulnerability is very brief. It notes that countries “may use appropriate methodologies and guidelines they consider better able to reflect their national situation”.
The lack of specific guidance is perhaps not surprising, given that – currently – scientists do not have a common method for developing robust climate information to support decisionmaking. This has been recognised by the World Climate Research Programme, which has set up a working group that aims to establish what it means for a scientific product to be “robust”, or fit for informing local or regional decisionmaking.
In the absence of specific guidance, norms appear to have developed in the national communications.
Most of the national communications in southern Africa include a dedicated section on future projections from climate models. These tend to use global or regional climate models, such as CORDEX Africa.
The climate projections included in the national communications have a strong emphasis on long-term changes to temperature and rainfall.
The plot below demonstrates how temperature and rainfall projections are used in different ways in the 16 national communications in the analysis. For example, it shows that 13 reports include projections of annual precipitation variables, 10 feature projections for seasonal precipitation change and nine mention annual temperature projections.
However, we find that few countries chose to focus on other variables – such as heatwave or extreme rainfall indices – in the climate projections section of their national communications, despite these extremes often resulting in large impacts.
While there was an emphasis on flooding and drought in many reports, this was typically found in the impacts and adaptation section, which was often disconnected from analysis of climate projections.
All 16 national communications cited floods as a “top five hazard” and 13 included drought. However, in sections on climate projections, the reports rarely included analyses beyond average temperature and rainfall. Just four national communications included projections of sea level rise, while projections for tropical storms, ocean temperature and flooding were featured in one each.
We also find the impacts and adaptation sections typically lean on impact modelling and experience from recent weather events, not climate projections analysis.
(Impact models are used to test how climatic changes might influence other systems, for example crops, water resources or human health. These impact models sometimes use climate projections as an input – but not always.)
In the national communications, we find that, in some instances, there was a clear link between the climate projections section and impacts assessment. However, this was not always the case.
Accounting for uncertainty
We also find that most national communications are not adequately accounting for uncertainty in climate projections.
Climate projections are generated by running climate models with hypothetical future scenarios. These scenarios take into account different socioeconomic pathways the world may take, with implications for the amount of greenhouse gases emitted and the amount of global warming.
Such is the complexity of the climate system and the many unknowns of how global society will develop in future, there is a wide range of uncertainty in the projections that models produce.
While temperature projections tend to be relatively consistent across different climate models, rainfall projections – especially in regions such as southern Africa – carry much greater uncertainty. For many countries, some models suggest it will be wetter in future, while other models suggest it will be drier.
However, we found this uncertainty was not always stated in national communications. For example, some national communications use only a single model, the average across a collection of models or a single emissions scenario – meaning the range of climate futures and risks countries could face is not always being considered.
To best support adaptation planning, climate projections should be combined with interpretation. When climate projection data are presented on their own, they only tell us what the models show. Interpretation is needed to help decisionmakers consider what this data can tell us about the real world.
(There is a good example from South Africa’s third national communication, which uses a relatively novel approach for representing uncertainty. It uses “narratives” to describe the different climate futures that are possible in each province, such as “hot and dry” or “warmer, wetter”.)
Overall, it is not clear if the climate science set out in national communications is being used when deciding on adaptation options – raising the question of what role future climate information is playing in the documents.
Barriers
Climate science is complex – communicating and interpreting findings, as well as uncertainties, can be challenging. Uncertain rainfall projections in southern Africa in particular is making decisionmaking difficult.
To understand the barriers to integrating climate projections into adaptation decisionmaking, we interviewed 18 experts. This included government decisionmakers and technical experts, as well as climate modellers and applied researchers tasked with translating science for government officials.
One impact modeller told us: “The [climate projection] results are not agreeing. So then the question is, which results do you adopt at national level?”
We find that end “users” of future climate information, such as governmental adaptation planners, are not always able to interpret complex or uncertain findings – and have trouble accessing spatially-detailed information they require.
In some sectors, such as water and infrastructure, users and decisionmakers are knowledgeable and accustomed with uncertain climate projections – but officials in sectors such as health are less familiar.
Meanwhile, the flow of information from climate scientist to decisionmaker is not always direct. Instead, experts in third-party organisations – such as applied researchers or impact modellers – play a role in passing on information.
These external experts – which we refer to in the study as “boundary agents” – can improve the translation and dissemination of information between scientists and decisionmakers. However, in some instances, information is lost.
Our analysis shows that climate projections can become increasingly more certain as they are passed along by boundary agents. As one experienced climate scientist who has helped develop numerous national documents to the UN explained:
“Sometimes you use words like: ‘This looks like [a] plausible [pathway], this is one of the likely [pathways] that this signal is going to look like’ … But even if you have tried to maintain that these are probabilistic statements…don’t be surprised when you go some pages down the line [to read]: ‘this region is likely to get warmer by 5C’. Then you get a statement that says, ‘according to the climate model, we’re going to experience 5C warmer temperatures in the future’.“
Lessons for the future
Our study analyses tips from experts on how climate science could be more effectively used in adaptation planning, based on real-world experience.
The measures highlighted by the experts include:
- Creating spaces for collaboration between scientists and adaptation decisionmakers.
- Inviting adaptation decisionmakers to be included in the development of scientific analyses, to boost their understanding of uncertainty and different climate variables. This could also help scientists better understand the information needs of adaptation decisionmakers.
- Explaining climate science jargon, including by avoiding abbreviations such as DJF (meteorological nomenclature for December, January and February) or SSP (for shared socioeconomic pathways).
- Clarifying what is meant when discussing uncertainty, given that climate scientists are likely to be discussing uncertainties in climate modelling while adaptation planners uncertainty in governance and finance.
- Ensuring that maps and figures designed to communicate uncertainty are intuitive to people outside the world of climate science.
Overall, our research shows that there are adaptation processes in southern Africa where future climate projections are being included. However, it raises questions about how far the implications of future climate change are being integrated and understood.
Work is needed to incorporate a broader range of climate projections into planning – in particular, variables related to extreme weather such as heatwaves and flooding, which lead to large impacts, such as heat-related deaths or destruction of crops.
The uncertainties in climate projections must also be better considered, communicated and understood. This challenge is not unique to southern Africa; scientists around the world have important work to do to figure out how to communicate “robust” future climate information to decisionmakers.
Enhanced collaboration between climate scientists and planners, improved communication approaches and effective use of “boundary” organisations can help remove some of the barriers to the effective use of climate science in national adaptation planning in southern Africa.
The post Guest post: How climate science is – and is not – shaping adaptation planning in southern Africa appeared first on Carbon Brief.
Guest post: How climate science is – and is not – shaping adaptation planning in southern Africa
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: