Every year, understanding of climate science grows stronger.
With each new research project and published paper, scientists learn more about how the Earth system responds to continuing greenhouse gas emissions.
But with many thousands of new studies on climate change being published every year, it can be hard to keep up with the latest developments.
Our annual “10 new insights in climate science” report offers a snapshot of key advances in the scientific understanding of the climate system.
Produced by a team of scientists from around the world, the report summarises influential, novel and policy-relevant climate research published over the previous 18 months.
The insights presented in the latest edition, published in the journal Global Sustainability, are as follows:
- Questions remain about the record warmth in 2023-24
- Unprecedented ocean surface warming and intensifying marine heatwaves are driving severe ecological losses
- The global land carbon sink is under strain
- Climate change and biodiversity loss amplify each other
- Climate change is accelerating groundwater depletion
- Climate change is driving an increase in dengue fever
- Climate change diminishes labour productivity
- Safe scale-up of carbon dioxide removal is needed
- Carbon credit markets come with serious integrity challenges
- Policy mixes outperform stand-alone measures in advancing emissions reductions
In this article, we unpack some of the key findings.
A strained climate system
The first three insights highlight how strains are growing across the climate system, from indications of an accelerating warming and record-breaking marine heatwaves, to faltering carbon sinks.
Between April 2023 and March 2024, global temperatures reached unprecedented levels – a surge that cannot be fully explained by the long-term warming trend and typical year-to-year fluctuations of the Earth’s climate. This suggests other factors are at play, such as declining sulphur emissions and shifting cloud cover.
(For more, Carbon Brief’s in-depth explainer of the drivers of recent exceptional warmth.)
Ocean heat uptake has climbed as well. This has intensified marine heatwaves, further stressing ecosystems and livelihoods that rely on fisheries and coastal resources.
The exceptional warming of the ocean has driven widespread impacts, including massive coral bleaching, fish and shellfish mortality and disruptions to marine food chains.
The map below illustrates some of the impacts of marine heatwaves from 2023-24, highlighting damage inflicted on coral reefs, fishing stocks and coastal communities.
Land “sinks” that absorb carbon – and buffer the emissions from human activity – are under increasing stress, too. Recent research shows a reduction in carbon stored in boreal forests and permafrost ecosystems.
The weakening carbon sinks means that more human-caused carbon emissions remain in the atmosphere, further driving up global temperatures and increasing the chances that warming will surpass the Paris Agreement’s 1.5C limit.
This links to the fourth insight, which shows how climate change and biodiversity loss can amplify each other by leading to a decrease in the accumulation of biomass and reduced carbon storage, creating a destabilising feedback loop that accelerates warming.
New evidence demonstrates that climate change could threaten more than 3-6 million species and, as a result, could undermine critical ecosystem functions.
For example, recent projections indicate that the loss of plant species could reduce carbon sequestration capacity in the range of 7-145bn tonnes of carbon over the coming decades. Similarly, studies show that, in tropical systems, the extinction of animals could reduce carbon storage capacity by up to 26%.
Human health and livelihoods
Growing pressure on the climate system is having cascading consequences for human societies and natural systems.
Our fifth insight highlights how groundwater supplies are increasingly at risk.
More than half the global population depends on groundwater – the second largest source of freshwater after polar ice – for survival.
But groundwater levels are in decline around the world. A 2025 Nature paper found that rapid groundwater declines, exceeding 50cm each year, have occurred in many regions in the 21st century, especially in arid areas dominated by cropland. The analysis also showed that groundwater losses accelerated over the past four decades in about 30% of regional aquifers.
Changes in rainfall patterns due to climate change, combined with increased irrigation demand for agriculture, are depleting groundwater reserves at alarming rates.
The figure below illustrates how climate-driven reductions in rainfall, combined with increased evapotranspiration, are projected to significantly reduce groundwater recharge in many arid regions – contributing to widespread groundwater-level declines.
These losses threaten food security, amplifying competition for scarce resources and undermining the resilience of entire communities.
Human health and livelihoods are also being affected by changes to the climate.
Our sixth insight spotlights the ongoing and projected expansion of the mosquito-borne disease dengue fever.
Dengue surged to the largest global outbreak on record in 2024, with the World Health Organization reporting 14.2m cases, which is an underestimate because not all cases are counted.
Rising temperatures are creating more favourable conditions for the mosquitoes that carry dengue, driving the disease’s spread and increasing its intensity.
The chart below shows the regions climatically suitable for Aedes albopictus (blue line) and Aedes aegypti (green line) – the primary mosquitoes species that carry the virus – increased by 46.3% and 10.7%, respectively, between 1951-60 and 2014-23.
The maps on the right reveal how dengue could spread by 2030 and 2050 under an emissions scenario broadly consistent with current climate policies. It shows that the climate suitable for the mosquito that spreads dengue could expand northwards in Canada, central Europe and the West Siberian Plain by 2050.
The ongoing proliferation of these mosquito species is particularly alarming given their ability to transmit the zika, chikungunya and yellow fever viruses.
Heat stress is also a growing threat to labour productivity and economic growth, which is the seventh insight in our list.
For example, an additional 1C of warming is projected to expose more than 800 million people in tropical regions to unsafe heat levels – potentially reducing working hours by up to 50%.
At 3C warming, sectors such as agriculture, where workers are outdoors and exposed to the sun, could see reductions in effective labour of 25-33% across Africa and Asia, according to a recent Nature Reviews Earth & Environment paper.
Meanwhile, sectors where workers operate in shaded or indoor settings could also face meaningful losses. This drain on productivity compounds socioeconomic issues and places a strain on households, businesses and governments.
Low-income, low-emitting regions are set to shoulder a greater relative share of the impacts of extreme heat on economic growth, exacerbating existing inequalities.
Action and policy
Our report illustrates not only the scale of the challenges facing humanity, but also some of the pathways toward solutions.
The eighth insight emphasises the critical role of carbon dioxide removal (CDR) in stabilising the climate, especially in “overshoot” scenarios where warming temporarily surpasses 1.5C and is then brought back down.
Scaling these CDR solutions responsibly presents technical, ecological, justice, equity and governance challenges.
Nature-based approaches for pulling carbon out of the air – such as afforestation, peatland rewetting and agroforestry – could have negative consequences for food security, biodiversity conservation and resource provision if deployed at scale.
Yet, research has suggested that substantially more CDR may be needed than estimated in the scenarios used in the Intergovernmental Panel on Climate Change (IPCC’s) last assessment report.
Recent findings showed that a pathway where temperatures remain below 1.5C with no overshoot would require up to 400Gt of cumulative CDR by 2100 in order to buffer against the effect of complex geophysical processes that can accelerate climate change. This figure is roughly twice the amount of CDR assessed by the IPCC.
This underscores the need for robust international coordination on the responsible scaling of CDR technologies, as a complement to ambitious efforts to reduce emissions. Transparent carbon accounting frameworks that include CDR will be required to align national pledges with international goals.
Similarly, voluntary carbon markets – where carbon “offsets” are traded by corporations, individuals and organisations that are under no legal obligation to make emission cuts – face challenges.
Our ninth insight shows how low-quality carbon credits have undermined the credibility of these largely unregulated carbon markets, limiting their effectiveness in supporting emission reductions.
However, emerging standards and integrity initiatives, such as governance and quality benchmarks developed by the Integrity Council for Voluntary Carbon Markets, could address some of the concerns and criticism associated with carbon credit projects.
High-quality carbon credits that are verified and rigorously monitored can complement direct emission reductions.
Finally, our 10th insight highlights how a mix of climate policies typically have greater success than standalone measures.
Research published in Science in 2024 shows how carefully tailored policy packages – including carbon pricing, regulations, and incentives – could consistently achieve larger and more durable emission reductions than isolated interventions.
For example, in the buildings sector, regulations that ban or phase out products or activities achieve an average effect size of 32% when included in a policy package, compared with 13% when implemented on their own.
Importantly, policy mixes that are tailored to the country context and with attention to distributional equity are more likely to gain public support.
These 10 insights in our latest edition highlight the urgent need for an integrated approach to tackling climate change.
The science is clear, the risks are escalating – but the tools to act are available.
The post Guest post: 10 key climate science ‘insights’ from 2025 appeared first on Carbon Brief.
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.