Each ice and snow are strong types of water. They’re, nonetheless, distinct states shaped in another way: snow is manufactured from delicate ice crystals produced by water vapor within the clouds, whereas ice is just frozen liquid water. Massive quantities of compacted snow can flip into ice, nonetheless.
I grew up within the Midwest. That implies that as a baby, because the joke goes, I needed to resolve on a Halloween costume that would incorporate my winter coat. That could be why October, even now, nonetheless indicators “snow season” for me, despite the fact that I now not reside within the central a part of the US.
Snow season isn’t solely a stunning, white time of yr, it’s a necessary one. Among the most dramatic climatic instances in our planet’s historical past are “Snowball Earth” occasions that occurred lots of of hundreds of thousands of years in the past, when nearly all the globe was encased in ice as much as 0.6 miles thick. Now, new analysis means that the final Snowball Earth occasion preceded an explosion of life on Earth, together with the emergence of the primary animals. As we speak, the world’s life-sustaining water provide nonetheless comes from snow, as snowmelt is an important supply of the contemporary water that replenishes lakes, rivers and groundwater for billions of individuals. And a brand new metric is offering us with a extra holistic have a look at simply how a lot water is saved within the snowpack and for the way lengthy.
Snow, nonetheless, is turning into rarer. Lately, scientists in Norway’s Svalbard have been shocked to seek out greenery and rain as a substitute of snow throughout Arctic winter fieldwork. Their expertise highlights not simply the world’s warming however a full, seasonal shift with main penalties for local weather suggestions, ecosystems and analysis feasibility.
Unpredictable and hotter winter climate is creating thinner layers of black ice (the dense sort) and typically a corresponding thicker layer of white ice, the unstable kind. The 2 mixed could make for treacherous situations.
Nearer to house, planetary warming can also be affecting snow’s “cousin”: ice. The ice on the lake in your hometown might look protected for a recreation of pickup hockey or a bout of ice-skating, however seems to be might be deceiving. Warming winters usually are not solely affecting ice thickness and timing—when a lake freezes and thaws—but additionally high quality, making it doubtlessly unstable and unsafe.
Snowball Earth occasions and the emergence of the primary animals
Snowball Earth occasions are durations in Earth’s historical past when the planet’s floor, together with the oceans, grew to become nearly totally lined in ice. They’ve occurred solely a handful of instances and don’t happen in common cycles. Every occasion lasts for hundreds of thousands of years—or tens of hundreds of thousands of years—and is adopted by intense warming. Proof for these excessive glaciations contains glacial deposits present in areas that have been as soon as close to the equator. The newest Snowball Earth occasion occurred about 720 to 635 million years in the past, earlier than the emergence of complicated animal life.
Till now, the main points of those transitions have been poorly understood. However new analysis from the College of Washington is offering a extra full image for the way the final Snowball Earth occasion ended and a principle for why it preceded such a pronounced enlargement of life on Earth.
Geological proof, comparable to glacial deposits, signifies that Earth skilled excessive glaciations, often known as “Snowball Earth” occasions.
Cap carbonates—layered dolomite or limestone rocks which have a definite chemical make-up and that as we speak are discovered in additional than 50 international places, together with Australia, Dying Valley in the US, Eire, Namibia and Siberia—are thought to have shaped about 640 million years in the past because the Earth-encircling ice sheets melted, inflicting not solely main modifications in atmospheric and ocean chemistry however the depositing of this distinctive kind of sediment on the ocean flooring. They’re known as caps as a result of they’re discovered above the glacial deposits left after a Snowball Earth occasion and carbonates as a result of each dolomite and limestone are carbon-containing rocks. Cap carbonates protect clues to the Earth’s ambiance and oceans which might be sooner than what ice cores or tree rings can report.
The College of Washington examine, printed within the journal Nature Communications in August 2024, fashions the chemistry and geology throughout three phases of a Snowball Earth occasion. First, throughout Snowball Earth’s peak, the thick ice enclosing the planet displays daylight, however some areas of open water permit an change between the ambiance and the ocean. In the meantime, frigid seawater continues to react with the ocean flooring. Finally, carbon dioxide builds up within the ambiance to the purpose the place it traps sufficient photo voltaic vitality to lift international temperatures and soften the ice. This lets rainfall attain the Earth and contemporary water to circulate into the ocean to hitch a layer of glacial meltwater that floats over the denser, salty ocean water. This layered ocean slows down ocean circulation. Later, ocean churning picks up; and mixing between the ambiance, higher ocean and deep ocean resumes.
For greater than 2 billion years main as much as the newest Snowball Earth occasions, life was easy: it was within the type of algae, microbes or different tiny, aquatic organisms. In actual fact, the billion years previous the latest Snowball Earth occasion are known as the “boring billion” as a result of so little occurred. Then got here a Snowball Earth; and shortly after, animals seem within the fossil report.
Some life-forms, comparable to cyanobacteria, survived Snowball Earth situations. Often known as blue-green algae, cyanobacteria carry out photosynthesis to create vitality from daylight. They exist as single cells, filaments or colonies and as we speak are present in numerous habitats, comparable to contemporary water and scorching springs.
Now that we all know the necessary environmental modifications—which affected the acidity, circulation and temperature of the oceans—that occurred as Earth recovered from the Snowball Earth interval, state the College of Washington researchers, we will extra confidently determine how they impacted life on Earth. Future analysis will discover how pockets of life that survived the tumult of a Snowball Earth occasion and its aftermath may have advanced into the extra complicated life-forms that shortly adopted.
Snowpacks and the Earth’s water-storage system
Whereas a heavy snowpack is enjoyable for skiers and sledders, it additionally acts like an open-air storage tank that melts away to supply water for consuming, irrigation and different functions throughout dry months. However precisely how a lot water is held in snowpacks and for the way lengthy?
That data, vital to water managers worldwide, has taken on new readability due to a brand-new calculation approach developed by researchers within the Oregon State College (OSU) Faculty of Engineering. Water managers have a tendency to contemplate a portfolio of infrastructure choices—comparable to groundwater recharge applications and floor water reservoirs—to match provide to demand. Elevated understanding of how a lot water is in snow ought to permit them to make long-term planning choices for the best way to alter that portfolio.
“Snowpack” refers back to the seasonal accumulation of slow-melting, packed snow, usually discovered within the mountains. The April 1 snowpack metric helps forecast the water provide by indicating how a lot water from snowmelt will likely be obtainable in the course of the spring and summer season for agriculture and ecosystems.
The OSU researchers checked out almost 4 a long time of snowpack information. By their new metric, which they name “snow water storage,” they recognized a 22% drop in how a lot water is held yearly within the mountain snowpacks of the Decrease 48 states. In contrast to different broadly used metrics—such because the April 1 snowpack, which captures snow variables at a single cut-off date; or size of snow season, which describes the beginning and finish dates of snow cowl at a selected place—snow water storage is relevant at quite a few time and area scales. It’s a cumulative sum, clarify the scientists, not a most worth; it’s like including up the variety of miles you drive in a given yr reasonably than simply enthusiastic about the five hundred you probably did on at some point.
Along with introducing a greater software for gauging how a lot water is in snowpacks over durations of time, the findings are necessary due to what the brand new metric reveals about mountain snowpacks, which play an outsize function within the nation’s water storage. Of all of the water saved within the type of snow within the Decrease 48, 72% of it’s within the mountains, although mountains cowl simply 16% of the overall space.
The researchers’ work, offered in a paper printed within the journal Hydrology and Earth System Sciences in February 2024, builds on a generally used measurement often known as snow water equal, which is how a lot water is left in a container after the snow that was positioned in it melts. By contemplating the quantity of water held within the snowpack and the period of time the water is saved as snow, the scientists have been capable of quantify water storage in various kinds of snowpacks. This contains persistent snowpacks, comparable to these which might be usually in excessive elevations within the mountains; transient snowpacks, that are often discovered at decrease elevations; and snowpacks which might be transitioning from persistent to transient on account of local weather warming.
In Oregon, the place 15% of the state’s complete annual precipitation falls as snow, the state’s snowpack capabilities like a reservoir. It holds again winter precipitation and slowly releases it in spring and early summer season.
As a result of the snow water storage metric might be utilized to a number of varieties of snowpacks, it might develop into more and more precious for monitoring and predicting water sources amid a way forward for elevated local weather variability, conclude the authors of the paper. They level out that the previous a number of years within the Decrease 48 have seen a “feast or famine cycle of extremes” relating to the the place and the when of our rain and snow. And, on the whole, snowpacks have significantly declined over the previous 10 to twenty years.
That significantly issues in locations like Oregon, the place 15% of the state’s complete annual precipitation falls as snow, and the state’s snowpack capabilities like a reservoir. It holds again winter precipitation and slowly releases it in spring and early summer season. That is helpful as a result of, at these instances, rainfall has tapered off for the yr, however demand for water rises. Because the local weather warms and snowpacks develop into extra variable, a metric like the brand new one developed at OSU helps to extra objectively quantify the reservoir storage facet of the globe’s snowpacks.
Snowless winters and the warming Arctic
Sadly, snow is getting tougher to seek out. Particularly in locations comparable to Norway’s Svalbard, which is warming six to seven instances sooner than the worldwide common charge. Svalbard is on the forefront of the local weather emergency, with winter temperatures rising at almost double the annual common. In actual fact, winter warming within the Arctic is now not an exception however a recurring function of a profoundly altered local weather system, difficult the long-held assumption of a reliably frozen Arctic winter.
Winter within the Arctic is unraveling. Svalbard’s rain-soaked tundra and vanishing snowpack are upending each local weather science and survival in one of many world’s fastest-warming areas. In Svalbard in February 2025, researchers met exceptionally excessive temperatures, blooming vegetation and widespread snowmelt.
In a commentary printed within the journal Nature Communications in July 2025, environmental scientists at England’s Queen Mary College of London describe their fieldwork marketing campaign to check freshly fallen snow in Svalbard. However over a two-week interval, they have been capable of acquire contemporary snow solely as soon as, as a lot of the precipitation fell as rain. This lack of snowfall in the course of winter not solely disrupted their sampling plan but additionally made them query how protected or possible winter fieldwork actually is underneath such quickly altering situations. The skinny and slushy snow that hindered snowmobile entry to subject websites compelled the scientists to rethink how and even whether or not they can proceed winter science as standard. This additionally presents new security considerations, together with throughout rescue efforts or for the flexibility of researchers to retreat shortly to the protection of the analysis station in the event that they encounter polar bears whereas working within the subject.
This firsthand expertise corroborates long-standing projections about Arctic amplification, nevertheless it additionally underscores the alarming pace at which these modifications are taking maintain. It’s having a transformative affect on the bodily surroundings, the dynamics of native ecosystems and the survival of Arctic wildlife. These warming occasions might also create a suggestions loop, accelerating permafrost thaw, microbial carbon degradation and the discharge of greenhouse gases throughout the Arctic. The noticed meltwater pooling above frozen floor—forming huge, short-term lakes and decreasing snow cowl to zero in massive areas—additional exposes the naked floor floor and results in widespread blooms of organic exercise.
The commentary requires pressing motion and elevated funding in wintertime Arctic monitoring, highlighting a major lack of information and understanding concerning Arctic techniques throughout this fastest-changing season. Local weather coverage should catch as much as the truth that the Arctic is altering way more shortly than anticipated, say the authors, and winter is on the coronary heart of that shift. Extra observations and experimentation are essential, not solely to determine baselines but additionally to undertaking future impacts. Moreover, the authors stress that policymaking should morph from reactive to anticipatory methods, recognizing winter as a vital season of threat. The challenges already confronted by well-equipped scientific bases on account of midwinter warming underscore the immense stress this would possibly place on distant Indigenous Arctic communities, their emergency responses, infrastructure and transport.
In a shortly warming Svalbard, polar bears face habitat loss and elevated battle with people as they’re compelled ashore extra usually on account of melting sea ice. This drives them to seek out new meals sources, typically raiding hen nests or looking reindeer, and results in extra bear-human encounters.
In conclusion, the researchers state that “We would have been too cautious with our messages. Irreversible modifications to the Arctic local weather are occurring in entrance of our personal eyes.”
Ice degradation and the life under
When lakes and rivers freeze, there are two predominant layers of ice: white ice and black ice. White ice is mostly opaque, like snow, and stuffed with extra air bubbles and smaller ice crystals, diminishing its energy and stability; whereas black ice is evident and dense with few air pockets and bigger ice crystals, making it so much stronger. White ice is roughly lower than half the energy of black ice. Ice high quality is necessary due to its direct implications for load-bearing capability for human security and for the way a lot mild will transmit underneath the ice for the life beneath it.
The issue is that local weather change is contributing to the unpredictable and hotter winter climate, creating thinner layers of black ice and typically a corresponding thicker layer of white ice, the unstable sort. The 2 mixed could make for treacherous situations for hockey gamers, ice anglers, ice truckers, skaters and snowmobilers, say researchers at Toronto, Canada’s York College in a paper printed within the journal Nature Critiques Earth and Setting in September 2024.
A number of research have checked out lake ice amount and its period, however there’s little analysis on the standard of the ice, which instantly corresponds to how protected it’s for venturing out on.
Thickness alone is now not predictor of protected ice. If there’s an excessive amount of white ice and never sufficient black ice, the ice might not be sturdy sufficient to carry an individual’s weight. 4 inches of black ice are required for a human to exit on the ice to play or skate. A transport truck requires about 42 inches of black ice. However with a predicted 95% to 99% loss in ice-road transportation infrastructure with out significant diversifications for ice security, distant communities are vulnerable to being cutoff and unable to entry meals, medicines and provides in the course of the winter.
The shortage of consideration for high quality ice is already resulting in a lack of life. In Canada in December 2023, six individuals died inside every week of plunging by skinny ice. Two extra died in Ontario in February 2024. In that very same yr in Finland, 4 individuals died from falling by weak ice in January and February alone, the place the typical is eighteen individuals yearly. In Sweden, 16 individuals drowned from falling by the ice in 2014 and at the least 9 died for a similar cause in 2021.
For the September 2024 examine, the York College researchers needed to cease taking ice measurements in mid-February on Ontario’s Lake Simcoe and in early March on Paint Lake within the Muskoka area as a result of the ice cowl was dangerously skinny. Adjustments in precipitation from unseasonably heat climate is creating a variety of the unsafe ice situations and unpredictability. Hotter temperatures, rain and even snow can alter the energy and thickness of lake ice. Lake ice has a reminiscence; all climate fluctuations are saved in it. If the temperature is above 32 levels Fahrenheit for a time period, if there’s rain, if there are extraordinarily sunny situations or if there are freeze-thaw occasions, the ice can develop into structurally much less steady, affecting its security for human use.
In winter on an ice street, a transport truck requires about 42 inches of black ice.
The diminishing high quality of ice additionally has an affect on the life under: the quantity of vitamins obtainable for fish and different aquatic organisms, comparable to invertebrates, in addition to phytoplankton which want mild for photosynthesis. A few of that mild is blocked with elevated white ice, compromising the well being of an ecosystem.
This examine is certainly one of only some that appears on the high quality of lake ice, state the researchers, and but that ice is altering dramatically. What’s wanted, they are saying, is common measurements of ice high quality, together with black and white ice thickness, all through the Northern Hemisphere.
Heavy snowfalls and mountain gazing
Lately, I traded my Midwest stomping floor for a spot within the Pacific Northwest. I usually miss the snows of “the earlier than”—once I lived in a distinct place and in a distinct time, previous to such a quickly warming local weather.
I miss the snows of “earlier than”: those I skilled earlier to my change of handle and such a quickly warming local weather. I’ll be glancing at Oregon peaks, like Mount Hood, subsequent summer season, hoping that the snow line strikes evermore downslope because the years go on.
Now, in my much less snowy bodily surroundings, there’s a time period I like to think about: snow line. It’s the border between winter and summer season expressed in altitudinal phrases. The snow line resides at sea degree towards the poles and climbs greater as one strikes towards the equator, in line with now fellow Oregonian and creator Kim Stafford within the e-book Dwelling Floor: Language for an American Panorama. The snow line fluctuates up and down a mountain between steady snow cowl and perennial open floor, he says. A excessive snow line within the mountains speaks to drought under, so a metropolis dweller within the West can usually gauge the approaching predicament with a look towards naked, summer season peaks.
I’ll be glancing at these summits subsequent summer season and each summer season thereafter, hoping at all times that the white line begins to maneuver down the slopes because the years go on.
Right here’s to discovering your true locations and pure habitats,
Sweet
