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Warming driven by deforestation caused an extra 28,000 heat-related deaths per year across Africa, South America and Asia over 2001-20, new research finds.
The study, published in Nature Climate Change, is the first to look at human health impacts of warming caused specifically by tropical deforestation, as opposed to the burning of fossil fuels, its lead author tells Carbon Brief.
The authors find that deforestation alone drove, on average, 0.45C of warming in the tropics over 2001-20, accounting for 64% of the total warming in regions with tropical forest loss.
They also find that tropical deforestation over 2001-20 exposed 345 million people to “local warming”, in addition to the warming they were already facing due to global warming.
Six out of every 100,000 people living in deforested areas died as a result of deforestation-induced warming during this time, they warn.
This number is higher in south-east Asia, with Vietnam setting a record of, on average, 29 deaths per 100,000 people.
A researcher who was not involved with the study tells Carbon Brief that the “sobering” paper “reframes tropical deforestation as not only a carbon emissions and ecological issue, but also a critical public health concern”.
Tropical deforestation
Tropical forests, mainly distributed across South America, Africa and Asia, account for 45% of global forest cover.
These regions are well-known for their high biodiversity and the crucial ecosystem services that they provide, such as carbon storage.
However, tropical forest loss is on the rise.
A record 6.7m hectares of previously intact tropical forest was lost last year, mainly due to fires and land clearing for agriculture. As the planet warms, worsening heat and drought extremes are also causing trees to become less resilient to change, resulting in forest degradation.
The new study uses data from the Global Land Analysis and Discovery laboratory at the University of Maryland to assess how tropical forest cover has changed year on year. The authors find that over 2001-20, a total of 1.6m square kilometres (160m hectares) of tropical forest was lost globally. This is shown on the map below, where blue indicates high forest loss and yellow indicates low loss.
The authors find the largest forest loss was in central and South America, but also highlight “extensive” loss in south-east Asia and tropical Africa.
Forest warming
Tropical deforestation has a wide range of negative consequences, including decreasing biodiversity, releasing carbon into the atmosphere and threatening the safety of Indigenous communities.
Loss of tree cover can also affect local temperatures by influencing the water cycle.
Water is constantly moving from the surface of the land into the atmosphere through a process called evapotranspiration. Plants play a crucial part in this process by moving water from the soil up through their roots and into their leaves, where it evaporates, cooling the air above. When trees are cut down, this cooling effect is reduced.
The authors use data of land surface temperatures from the NASA MODIS satellite to map warming in tropical regions over 2001-20. These results are shown in the map below, where red indicates warming and blue indicates cooling.
The authors find that between 2001-03 and 2018-20, surface temperatures increased by 0.34C in tropical central and South America, 0.1C in tropical Africa and 0.72C in south-east Asia. They add that “areas of forest loss coincide with areas of strong positive change in temperature across many regions of the tropics”.
By comparing their deforestation and surface warming maps, the authors find that deforested regions of the tropics saw an average of 0.7C warming over 2001-20, while areas that “maintained forest cover” saw an increase of only 0.2C.
By comparing the change in temperature in deforested regions with that in neighbouring locations without forest loss, they find that deforestation alone caused 0.45C of warming in the tropics over 2001-20 – accounting for 64% of total warming experienced over those regions.
Heat exposure
High temperatures can be deadly.
During periods of extreme heat, people can suffer from heat stroke and exhaustion – and even die. Those with underlying health conditions are at higher risk of fatal complications.
The authors use data from Oak Ridge National Laboratory’s LandScan to map where people live in the tropics. They estimate that 425 million people live in regions that were exposed to tropical deforestation over 2001-20, and just over three-quarters of them were exposed to warming as a result of the loss of forest cover.
Finally, the authors estimated “heat-related excess mortality” due to nearby tropical deforestation.
Using data from the 2019 Global Burden of Disease study, they determine the number of “non-accidental” deaths in each deforested tropical area. This excludes deaths from “external” causes, such as accidents and suicides, but includes “internal” causes, such as disease.
The researchers then used previously published “temperature-mortality” relationships for different countries. These relationships show the link between temperature and excess mortality rate, indicating the percentage increase in mortality for every degree of warming.
These relationships vary between countries, as people in hotter regions are generally better adapted to extreme heat.
By combining the data on local warming due to deforestation, temperature-mortality relationships and the non-accidental mortality data, the authors calculated how many non-accidental deaths would have been expected in deforested regions if they had not warmed due to the loss of forest cover.
By comparing the real and counterfactual mortality rates, the authors were able to calculate the total mortality burden due to tropical deforestation-induced warming.
Overall, the authors find that tropical deforestation drove an additional 28,300 deaths every year over 2001-20, accounting for 39% of the total heat-related mortality from global climate change and deforestation combined over locations of forest loss.
The study finds that, on average, six out of every 100,000 people living in deforested areas died as a result of deforestation-induced warming. However, these numbers vary by country.
The chart below shows the average annual deaths due to deforestation-induced heat per 100,000 people living in areas of forest loss.
Dr Carly Reddington is a research fellow at the University of Leeds and lead author of the study. She tells Carbon Brief that it is the “first study to look at human health impacts of tropical deforestation-induced warming”.
Dr Nicholas Wolff, a climate change scientist at the Nature Conservancy who was not involved with the study, tells Carbon Brief that the paper is “sobering”. He adds that it “reframes tropical deforestation as not only a carbon emissions and ecological issue, but also a critical public health concern”.
Data-scarce
The authors note that there are no country-specific heat vulnerability indices available for African countries. To develop their data for African countries, they used the average heat vulnerability index for South America.
Reddington tells Carbon Brief that Africa is the most “uncertain region” in the study and tells Carbon Brief that “more data is really crucial” to develop more accurate estimates.
Wolff tells Carbon Brief that extrapolating heat-mortality relationships “from data-rich regions to data-poor ones” is a “common practice in global-scale climate-health research”.
He praises the overall methodology as “innovative, transparent and scientifically sound, with appropriate caveats”.
Dr Luke Parsons, a climate modelling scientist at the Nature Conservancy, tells Carbon Brief that the conclusions are “robust”. However, he notes some “methodological issues” with the paper, such as the fact that all results are modelled, rather than measured.
He tells Carbon Brief that future work could assess “near-surface air temperature and humidity changes associated with deforestation, as well as study regional air temperature changes beyond deforested areas”.
While the new study focuses on warming within one square kilometre of forest loss, Reddington tells Carbon Brief that “deforestation is associated with warming up to 100km away”.
Furthermore, the study notes that the increase in deaths due to excess heat is likely to affect the most vulnerable members of society the most. It says:
“Vulnerable populations, particularly traditional and Indigenous communities, often live near deforested areas and face limited access to resources and infrastructure needed to cope with the combination of rising temperatures and environmental changes caused by deforestation and climate change.”
Wolff also stresses this disparity, adding that “many of these communities depend on forest clearing for agriculture, income and survival, and are forced to make difficult choices between short-term economic needs and long-term health and environmental stability”.
The authors also note that deforestation can drive a range of other interacting health problems, which were not considered in this study. For example, deforestation is linked to a rise in zoonotic diseases, such as malaria.
Dr Vikki Thompson, a climate scientist at the Royal Netherlands Meteorological Institute who was not involved in the study, says that the findings of the paper are “relevant to everyone”. She continues:
“We can reduce impacts of extreme heat by planting more trees and reducing deforestation everywhere, on both local and international scales.”
The post Warming due to tropical deforestation linked to 28,000 ‘excess’ deaths per year appeared first on Carbon Brief.
Warming due to tropical deforestation linked to 28,000 ‘excess’ deaths per year
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An older teaching about land acknowledgement
As I have come to understand the spirit and intention of land acknowledgement, I often return to fond memories of my grandmother and her words of wisdom. She taught that the health of the places we call home comes first, because the wellbeing of the people depends on it.
In her teaching, land acknowledgement began with the land. Long before it became a paragraph read at the start of a meeting, it was a way of recognizing a homeland: its waters, its species, its seasons, and the spirit that revealed whether the place was well.
Her teaching echoes a practice found across many Indigenous Nations. Haudenosaunee gatherings, for example, have long opened with the Ohén:ton Karihwatéhkwen, the Thanksgiving Address, often translated as “the words that come before all else.” The speaker greets and gives thanks to the people, the earth, the waters, the plants, the animals, the winds, the sun, the moon and the stars. Only after everything that sustains life has been acknowledged does the gathering turn to its own business.
That order changes what an acknowledgement is for. Its purpose was to share the story of a place with neighbours and to draw them into the work of tending it. People entered the story second, as the ones responsible for what had just been named.
Understood this way, an acknowledgement does more than open a meeting. It asks us to reconsider where we stand, and what we owe the ground beneath us.
Nations among nations
In her teaching, people are one nation among many. The salmon are a nation. So are the cedars, the bison, the medicine plants, and the pollinators. Each belongs to a place, carries its own responsibilities, and offers gifts no other nation can give.
This idea of kinship runs through many Indigenous philosophies. The phrase “all my relations,” heard in ceremonies and gatherings across Turtle Island, is a reminder that family extends beyond people to the animals, plants, waters and lands that make life possible. Some Indigenous languages carry the same understanding in their grammar, speaking of many plants, animals and natural forces as living beings rather than objects.
Sovereignty, understood through this relationship, is a kind of standing more than a form of control. Each nation belongs fully to its place and carries its share of that place’s life. No nation thrives alone, and none thrives by taking over the whole.
The land is also the source of instruction. Over generations, people watched how a river valley or a stretch of prairie kept itself well: who arrived when, who fed whom, and how much could be taken before the giving stopped. In my grandmother’s telling, those observations became instructions, and those instructions helped shape law and protocol. They guided when to harvest, where to camp, how to enter a neighbour’s territory, and what was owed in return.
Indigenous legal scholars today often describe this as law that comes from the land itself, learned by watching how living systems sustain one another. A plainer name for it is knowing how to live somewhere.
The host and the guest
One of the clearest teachings in this understanding of the world is the relationship between host and guest. My grandmother invited us to recognize that relationship in the lives of plants and animals.
A host prepares the place before anyone arrives. A beaver family dams a stream, and the pond becomes a home for fish, frogs, birds and plants. A fallen tree becomes a nurse log, feeding the next generation of seedlings as it returns to the soil.
A host offers first. A flowering plant sets out nectar. A berry bush ripens fruit. These provisions come in their own season, not whenever a visitor happens to want them.
A host also makes its presence known. Birdsong, scent and the marks left along a trail tell newcomers that a place is already inhabited. The visitor does not arrive in an empty world.
The guest has responsibilities too. A guest attends to the season and to what the place can offer. A guest does not assume that everything within reach is theirs to take. A guest leaves something that helps sustain the relationship.
A bee takes nectar and carries pollen. Read through this teaching, that exchange offers an image of visiting well: receiving a gift while helping the host continue its life.
Many Indigenous harvesting protocols carry the same ethic into daily practice: ask before taking, take only what is needed, offer thanks, and leave enough for others and for the plant or animal to recover.
None of this suggests that every relationship in nature is peaceful or generous. These are ways of seeing responsibilities that people can learn to carry.
Everyone is both
No being is only a host or only a guest.
A tree makes room for other life while depending on soil, water, sunlight, fungi, and relationships beyond itself. People, too, may welcome others into their homes while remaining dependent on the larger homeland that sustains them.
The distinction between host and guest is therefore about roles, not ranks. Everyone receives. Everyone has something to give.
The question is whether the exchange sustains the place.
A visitor who takes without restraint leaves less for those who come next. A host who neglects the place has less to offer. Both have responsibilities, and neither can fulfil them alone.
This is the heart of reciprocity, a principle found across Indigenous philosophies: relationships stay healthy when gifts move in both directions. The Haudenosaunee teaching of the seventh generation extends that exchange across time, asking that decisions made today leave the place well for those not yet born.
Mutual benefit begins here, with the recognition that different beings carry different gifts and obligations.
What people carry forward
My grandmother’s teaching connects these relationships to the ways people meet their neighbours.
The host prepares a place, offers food and rest, and explains where the visitor has arrived. The guest makes themselves known, explains why they have come, listens to the terms of the visit, and brings something in return. The gift may be material. It may also be labour, knowledge, news, or a commitment to help.
Nations around the Great Lakes carried this ethic into treaty. The Dish with One Spoon, an agreement among the Haudenosaunee, Anishinaabe and allied Nations, describes shared hunting grounds as a single dish. Everyone eats from it with one spoon, takes only what they need, leaves enough for others, and keeps the dish clean. The Two Row Wampum, between the Haudenosaunee and European newcomers, shows two vessels travelling side by side on the same river, each keeping its own ways and neither steering the other.
In this understanding, acknowledgement is more than naming the people associated with a territory. It is learning enough about a homeland to behave responsibly within it.
Whose home is this? What sustains it? What laws and agreements guide our presence? What can we receive, and what must we return?
These questions make acknowledgement a relationship rather than a recital.
They also make it diplomatic. A guest who recognizes the host’s homeland recognizes that they have entered a place with its own relationships and responsibilities. A host who welcomes the guest makes room for an encounter governed by those relationships.
Neither arrives without standing. Neither arrives without obligations.
Beginning with place
I write from the shores of the Bay of Quinte. Here, the teaching asks me to begin with the water, the shoreline, and the life they sustain. Before I describe myself, I must attend to where I am.
That does not make people or history less important. It places them within the homeland that gives them meaning. The people, their laws, their agreements, and their responsibilities all belong to the place.
In a time of longer fire seasons, troubled waters, and uncertainty about what the next season will bring, this teaching asks something difficult and useful of us: pay attention before you speak.
An acknowledgement cannot tell the story of a place if the speaker has stopped noticing it.
The land came first. Beginning there again means learning to name what sustains us, and accepting that what sustains us also asks something of us.
By Rye Karonhiowanen Barberstock
Photo by Andrik Langfield on Unsplash
The post The Land Came First appeared first on Indigenous Climate Hub.
Carbon dioxide (CO2) emissions from fossil fuels and cement are projected to fall by around 0.4% in 2026 to 38.2bn tonnes of CO2 (GtCO2), according to new figures from the Global Carbon Project.
This guest post is by:
- Dr Zeke Hausfather, Carbon Brief’s climate science contributor
- Prof Pierre Friedlingstein, chair of mathematical modelling of climate systems at the University of Exeter and part of the Global Carbon Project team.
Carbon dioxide (CO2) emissions from fossil fuels and cement are projected to fall by around 0.4% in 2026 to 38.2bn tonnes of CO2 (GtCO2), according to new figures from the Global Carbon Project.
The 21st edition of the annual “global carbon budget” report, published today, says that this small decline is largely due to a 1.9% drop in emissions from oil and the energy shock triggered by the Iran conflict and the closure of the strait of Hormuz.
Emissions from coal continue to increase slightly.
The Global Carbon Project’s projections for fossil fuel and cement CO2 emissions in 2026 are preliminary, with a range that spans a fall of -1.5% to a rise of +0.6%.
This means a small increase in emissions can not be ruled out.
Emissions from land-use change, such as deforestation, are projected to rise in 2026.
This is primarily driven by peat fires and forest degradation in south-east Asia and is linked to the development of a strong El Niño event this year.
As a result, total CO2 emissions from fossil fuels and land use are projected to reach a record high of 43.3GtCO2 in 2026 – marginally above 42.8GtCO2 in 2025.
Research published alongside the report by the same team in Nature Climate Change finds that the growth in solar, wind and electric vehicles (EVs) now offsets around two-thirds of the emissions that would otherwise come from rising energy demand.
However, the deployment of these technologies is not yet enough to push global emissions into a sustained decline, according to the study.
The 2026 global carbon budget report also estimates that:
- Fossil emissions are projected to fall in China (-0.9%), the US (-1.3%) and the EU (-1.5%) in 2026, but rise by 4.4% in India.
- Oil emissions are projected to fall in every major region, with the largest dr