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The term “global warming” is typically used to describe increasing global temperatures as a result of human emissions of carbon dioxide (CO2) and other greenhouse gases.
However, unusually cold events are often portrayed as being made worse by human activity, as a result of increased variability or a disruption of the “polar vortex” in a fast-warming world.
There is significant debate in the scientific community about whether rapid Arctic warming and sea ice loss could disrupt atmospheric circulation patterns and lead to cold-air outbreaks in the northern hemisphere mid-latitude regions.
In a new analysis, Carbon Brief shows that few places in the world have seen an increase in extreme cold days over the past 55 years.
If climate change is influencing atmospheric circulation, any effects on extreme cold appear to be more than compensated by the rapid winter warming the world has experienced.
A controversial hypothesis
In an episode of Marketplace’s How We Survive podcast last year, the host – US radio journalist Kai Ryssdal – noted that climate change is expected to cause “hotter hots [and] colder colds in unexpected parts of the world”.
This is not an uncommon sentiment, with the media commonly attributing extreme cold events to human activity, particularly during episodes of bitter cold or polar-vortex events.
Some researchers have argued that these extreme cold snaps might be becoming more frequent due to reduced sea ice and Arctic amplification – the phenomenon where the Arctic warms more quickly than the global average.
At the core of the hypothesis that Arctic warming could influence mid-latitude cold extremes is the fact that a rapidly warming Arctic changes the temperature difference between the poles and the equator.
Normally, the strong contrast in temperature between these regions drives key patterns of atmospheric circulation, including the jet stream. According to proponents of this theory, when Arctic temperatures rise faster than those farther south, atmospheric circulation can weaken, meander, or buckle more frequently. As a result, cold polar air can spill down into areas that are usually less frigid.
A related argument focuses on how diminished sea ice – particularly in the Barents and Kara seas – might disrupt the atmosphere. Less sea ice means more heat and moisture escapes from the ocean surface into the air, which can potentially alter weather patterns downstream. This can boost the odds of “blocking high” weather systems, or unusual circulation patterns that pull cold air into mid-latitudes.
However, there are relatively few studies that attribute an increase in cold extremes – or an individual extreme cold event – to human activity.
Carbon Brief’s attribution map – which charts extreme weather events around the world and their links to human-caused warming – includes 33 studies that examine extreme cold events specifically.
Of these, 24 studies found that the extreme cold was made less likely due to climate change, six found no discernible human influence and three found insufficient data to conclude either way. Only one extreme event attribution study in the database found that a cold extreme – severe frosts in Western Australia in 2016 – was made more likely due to climate change. However, even that study noted that “warmer temperatures may have offset or countered this effect of the circulation driver”.
Many climate scientists disagree with the hypothesis that warming could lead to increased cold outbreaks, arguing that cold extremes are decreasing overall in a warming world.
Others contend that causality cannot yet be proved and that both models and observations provide limited support for a significant role of climate change in mid-latitude cold events.
In addition, observed data reveals that, although cold spells still occur, they have become less frequent and less intense over recent decades. Most modeling studies do not consistently reproduce more frequent or severe cold outbreaks. Instead, they often show that the overall warming trend dominates, making cold extremes rarer over time.
This suggests that, if there were a connection between climate change and extreme cold events, the long-term warming trend will still likely lead to fewer, milder cold outbreaks – and that any effect from Arctic amplification would be relatively small.
Have any regions experienced increased cold events?
To help assess the effects of climate change on extreme cold events, Carbon Brief used gridded daily minimum global temperature data from Berkeley Earth to calculate how the temperatures of the coldest 5% of the days of the year have changed since the 1970s.
Minimum daily temperatures reflect the single coldest measurement taken over the course of the day. (While the coldest 5% of days is a somewhat arbitrary number, the results are largely similar for the coldest 10%, 5%, 2%, 1%, or the single coldest day of the year.)
The figure below shows the results for every one-by-one degree latitude-longitude grid cell on the Earth’s land (a size approximately equivalent to 100km by 100km). Grid cells coloured red experienced a decrease in extreme cold days, while those coloured blue had more extreme cold days.
The vast majority of the planet has seen a strong decrease in extreme cold events, with the largest declines seen in high-latitude northern hemisphere regions (which have also experienced the fastest rate of warming overall).
The few regions that have seen an increase in extreme cold events tend to be those with the slowest average rates of warming, including India, South Africa and Antarctica.
In India, this has likely been influenced by rapid increases in air pollution – particularly cooling sulfate aerosols – over this period. Causes of more extreme cold events in Antarctica are less clear, though it is possible that they could be linked to the seasonal loss of ozone layer over the past 50 years.
Another way to assess changes in cold events is to look at the change in the number of days where any hour of the day – that is, the daily minimum temperature – is below freezing (0C, 32F). The map below shows the change in average annual freezing days between 1970 and 2024.
The map shows dramatic shifts in the number of freezing days in much of the high-latitude northern hemisphere, with nearly a month fewer freezing days over the Himalayas, eastern Europe and parts of Canada and the western US over the past 50 years.
(White areas on the graph – such as much of the tropics and subtropics – represent regions of the world where temperatures below freezing almost never occur and thus changes over time cannot be calculated.)
Fewer cold outbreaks in the US
A sizable portion of the academic research on cold outbreaks has been focused on the contiguous US, as it is a region prone to occasional extreme cold conditions caused by intrusions of Arctic air.
The map below shows there has been a warming trend in the coldest days of the year across virtually the entire US over the past 50 years.
This suggests that the effect of Arctic amplification on cold-air patterns is smaller than the strong winter warming trend.
Almost no regions of the US have seen a cooling trend in the 5% coldest days of the year – and higher latitude regions have tended to experience the fastest winter warming.
There has been a slight cooling trend in the coldest days of the year in northern Mexico and slower warming in California, Arizona, southern New Mexico and southern Texas.
Similarly, the figure below examines the change in days where minimum temperatures are below freezing in the US.
It shows that there are, on average, 13 fewer days below freezing each year compared to the 1970s. Or, to put it another way, there is half a month where daily minimum temperatures are no longer cold enough for icy and snowy conditions to occur.
Increasingly rare cold spells
The latest climate models overwhelmingly project that cold extremes will continue to diminish as greenhouse gas concentrations rise.
This means that, even if certain patterns occasionally transport freezing polar air southward, winters on the whole are likely to be milder than in the past.
However, the scientific understanding of precisely how Arctic warming might – or might not – influence mid-latitude weather is still evolving.
Researchers continue to refine models, incorporate better reanalysis data and examine how changes in atmospheric circulation dynamics might play out under different scenarios. Additional data – especially over multiple decades – will help clarify whether the Arctic’s role in mid-latitude cold extremes is significant or overstated.
For now, observations over the past 50 years generally show a world with fewer cold extremes – and projections point toward increasingly rare cold spells in the future.
The post Factcheck: Climate change is not making extreme cold more common appeared first on Carbon Brief.
Factcheck: Climate change is not making extreme cold more common
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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 repor