Growing tall trees to provide shade for cocoa plantations in west Africa could sequester millions of tonnes of carbon, according to a new study.
The research, published in Nature Sustainability, finds that the additional carbon stored in shade trees, such as banana and palm trees, could entirely “offset” cocoa-related emissions in Ghana and Ivory Coast, without reducing production.
West Africa produces about 60% of the world’s cocoa, which is one of the most emissions-intensive crops to grow.
The authors map the shade provided by trees across cocoa agricultural systems in west Africa, then project how much additional carbon storage would be created by expanding it.
An author of the study tells Carbon Brief that cocoa plantations have been a “big” driver of deforestation and the emissions it causes, but the findings show that there is “huge potential” for cocoa to be “part of the solution”.
Cocoa plantations
Cocoa trees thrive in rainforests, as they need abundant rain, high humidity and stable temperatures. They often grow under the shadow of other plants, such as bananas, plantains and palm trees.
Two countries in west Africa – Ivory Coast and Ghana – dominate global cocoa production and are major exporters to the US and Europe.
The shading on the map below shows where cocoa is grown in Ivory Coast (left) and Ghana (right).
Both countries have favourable conditions for cocoa production, including tropical forests – which provide nutrients to the soil – a great deal of rain, warm temperatures and low production costs.
Two million farmers in the region rely on cocoa farming for their livelihoods, the study says, and cocoa contributes 10-20% of the two countries’ gross domestic product.
However, cocoa has “one of the most emissions-intensive footprints of all foods”, the study adds.
A 2022 study found that producing 1kg of cacao beans in Ivory Coast releases, on average, 1.5kg of CO2-equivalent (CO2e) – largely a result of deforestation. Since 2000, cocoa plantations have driven 37% of forest loss in protected areas in Ivory Coast and 13% of the loss in protected areas in Ghana.
Cocoa plantations cover more than three-and-a-half times as much land as the remaining intact forests in west Africa, according to the study.
Dr Wilma Blaser Hart, a research fellow at the University of Queensland and an author of the study, tells Carbon Brief:
“That land-use change is what makes cocoa such a carbon-intensive product, because there has just been so much forest loss for being able to produce cocoa.”
Shade-grown cocoa crops
Agroforestry is an agricultural method that combines the planting of crops with trees. Agroforestry can raise incomes for farmers and provide ecosystem services, including soil health improvement, biodiversity conservation and carbon sequestration.
The study investigates the amount of carbon that is currently stored in cocoa plantations in Ivory Coast and Ghana, as well as the potential carbon sequestration if agroforestry were expanded in these countries.
The authors use drones and machine learning to map the cover of shade trees, finding that 13% of the combined area of Ivory Coast and Ghana is currently covered with these trees.
In the study, “shade trees” refers to any trees taller than eight metres – the maximum height of cocoa trees.
The map below shows the area of shade trees in cocoa-growing areas specifically for 2022. The colours indicate levels of tree cover from 0-15% (blue), through to 15-30% (green) and more than 30% (yellow).
The map reveals that cocoa production is “overwhelmingly dominated by full-sun monocultures and low shade-agroforestry”, the study says.
Using satellite data, global maps of tree canopy height and on-ground verification, the researchers map the amount of “aboveground biomass” held by cocoa plantations.
Aboveground biomass comprises all living vegetation that lies above the soil – trees, leaves and other plant matter.
The map below shows the amount of aboveground biomass in both countries. The areas in yellow are those with the highest biomass and, therefore, more stored carbon.
The authors project that if all cocoa plantations increased their cover of shade trees to at least 30%, the additional, taller trees could sequester an “enormous” amount of carbon – 307m tonnes of CO2e (MtCO2e) – enough to fully counterbalance the current cocoa-related emissions in both countries, without reducing production.
Blaser Hart tells Carbon Brief:
“Cocoa itself is a small tree. [It] can grow up to about eight metres tall, so it also sequesters carbon. [But] we found that tall trees that are towering high above cocoa – often timber trees – sequester much more carbon than cocoa.”
In addition, she says, the cover from large trees is “much better for cocoa” since it protects them during the hottest hours of the day, while allowing light through. They also shed large amounts of “litter”, which gets incorporated as organic matter into the soil, sequestering carbon from the atmosphere.
Barriers and limitations
The authors acknowledge several limitations to their study.
For example, they say, the analysis may underestimate the proportion of shade tree cover by excluding trees shorter than eight metres. They also note that the analysis does not consider all of the features of agroforestry systems, such as which species are planted.
Kayeli Laurence is a PhD student of landscape ecology at Jean Lorougnon Guédé University in Ivory Coast and an expert in agroforestry. The researcher, who was not involved in the study, tells Carbon Brief:
“The identified limitations call for caution, particularly when it comes to local, small-scale analyses. However, they do not undermine the general trends highlighted by the study.”
Laurence notes that the study results are consistent with other research highlighting the carbon sequestration potential of agroforestry systems. She says that the projection of carbon sequestration is “ambitious, but credible”. However, she adds:
“In practice, achieving this goal will strongly depend on local conditions: availability of species, technical support, farmers’ willingness and, above all, economic incentives.”
The study also acknowledges that smallholder farmers in west Africa “face several barriers” to adopting agroforestry, including limited incentives and insecure land tenure.
The non-profit scientific research organisation Project Drawdown notes that implementing a certain category of agroforestry called “multistrata” – a combination of long-lasting crops and multiple layers of trees or vegetation – in humid tropical climates would cost more than $1,300 per hectare.
Blaser Hart tells Carbon Brief:
“That’s a huge cost. And it’s not money that farmers have available.”
International landscape
Blaser Hart says that cocoa agroforestry provides further benefits to ecosystems, besides carbon sequestration. These include cooling the air, improving soil fertility and nutrient cycling and providing habitat for wildlife. She adds:
“We’re currently doing a big study on how agroforestry can help to provide habitat for birds. There also seems to be a bit of mammals that use cocoa agroforestry systems. In Ghana, we’re finding quite a bit of genets and civets that are in these systems. From Brazil, there’s a bit of research in the Atlantic Rainforest that shows that some monkeys use them as permanent habitat and others just as corridors to move through.”
Agroforestry is included in the climate commitments of around 40% of developing countries under the Paris Agreement, according to the study.
At the corporate level, the cocoa industry has made commitments to plant “millions of shade trees in agroforests to improve the sustainability of the sector”, the study says.
Blaser Hart tells Carbon Brief that the researchers hope the work will encourage the cocoa industry to better plan its agroforestry interventions, “rather than just haphazardly handing out trees here and there”.
Laurence suggests that policymakers should improve climate finance to support farmers in transitioning to sustainable agricultural systems, while chocolate producers and certification bodies should make stronger commitments to create “real demand for sustainable cocoa produced through agroforestry”.
Ultimately, the study notes that the methods it developed to assess the status of trees in agricultural systems can be used for other commodities grown in agroforests, such as coffee.
The post Growing trees for shade has ‘enormous’ potential for cutting cocoa emissions appeared first on Carbon Brief.
Growing trees for shade has ‘enormous’ potential for cutting cocoa emissions
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 | Natu