Permafrost—soil, rocks, and sand that are held together by ice and remain frozen for at least two consecutive years—covers about 15% of the Northern Hemisphere's land area.

Arctic permafrost may store twice as much carbon as the entire atmosphere

Rising greenhouse gas concentrations are expected to continue to increase average global temperatures and threaten to thaw ground that has been frozen for thousands of years. The release of greenhouse gases from remnant organic matter would exacerbate the greenhouse effect, creating a positive feedback loop.

Why does it matter that the tundra is melting?

This article explores the tundra's unique environment, where specialized plants and animals thrive despite harsh conditions. One of the most important elements of this ecosystem is permafrost, a layer of permanently frozen soil that many tundra...

What threats are the tundra facing?

This article discusses the threats endangering the tundra, including climate change, air pollution, and human industrial activities. Climate change is causing permafrost in the tundra to thaw, releasing greenhouse gases and contributing to a cycle...

How glaciers melt

Greenland and Antarctica are home to most of the world's glacial ice, including its only two ice sheets, making them areas of particular interest to scientists. Watch this three-minute video to learn why understanding them is not just interesting, but crucial to our near-term adaptability and our long term survival in a changing world.

Soil is the largest terrestrial carbon sink on the planet, storing almost twice as much carbon as the atmosphere and all living plants and animals combined.

Without greenhouse gases, Earth's average surface temperature would be below freezing

Atmospheric molecules that absorb and emit infrared radiation from the planet's surface effectively trap additional incident solar energy that would otherwise escape to space. Without the greenhouse effect, the planet's average surface temperature would be approximately -18 degrees Celsius (0 degrees Fahrenheit).

Adapt or freeze: How plants and animals thrive in the Arctic Tundra

This article explores the fascinating ways both animals and plants adapt to survive in Alaska's arctic tundra, an ecosystem marked by its extreme weather. Most tundra plants are perennials with short growing seasons that focus on gathering and...

How melting ice impacts the whole world

Melting glaciers and ice caps are far from where most people live, but their impact can be felt across the planet. Visit four places—the American West, a Himalayan valley, the northern Atlantic, and Texas—with this immersive interactive to see the various impacts of melting ice around the world.

The Arctic is greening from rising temperatures

This one-minute video summarizes a new study that used satellite data to look at plant life across the entire Arctic area for the first time. It found that from 1985 to 2016, 38% of the areas studied—including parts of Alaska, Canada, and...

What is the tundra?

This article provides a geographical overview of the tundra biome. It explains the Arctic tundra is found in the Northern Hemisphere surrounding the Arctic Circle. A second type of tundra, called the alpine tundra, exists on high-altitude mountain...

The 300-million-year period where Earth looked like a snowball

Life has existed on Earth for at least 3 billion years, but the planet has not always looked like it does today. Rather than the blues and greens of our modern globe, for a 300 million-year period, the Earth was covered in ice and snow, from the poles to the equator. Surprisingly, life was thriving at the time.

The Arctic warms more quickly than the rest of the planet because of the loss of surface ice, a lack of vertical air circulation, and the release of thermal energy as water vapor condenses.

The world's largest deserts—areas that receive less than 10 inches of annual rainfall—are led by the Antarctic and Arctic regions.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Search for psychrotolerant and psychrophilic microorganisms found in Antarctica

Developed following a five-week expedition to the southern continent, "Life Under the Ice" allows users to examine a petri-dish-like microscopic world and uncover recordings of organisms that can withstand, or even thrive, in the harsh environment.

Ice ages are periods of glaciation that last tens of millions of years

During these periods, Earth grows cold and is covered in massive continental ice sheets. Scientists have outlined at least five major ice ages, which result from the alignment of complex factors, like the flow of ocean currents and the movement and location of tectonic plates.

'Watermelon snow'—patches of pink, orange, and red in snow—is the result of extremophilic green algae that thrive in extremely frigid conditions and take the shape of red spheres in winter.

Earth has shifted between extreme warming and cooling phases for 500 million years

Earth is in an interglacial period of the Quaternary glaciation, resulting in receding glaciers and mild temperatures. However, today's warming trend is occurring much faster than previous warming periods in the climate record.

Dinosaurs thrived in the Arctic year round

The Arctic in the Cretaceous Period was a rough place to live, especially in winter. And yet, the fossils of many kinds of dinosaurs have been discovered there. So how were they able to survive in this harsh environment?

Watch an animation of Arctic sea ice grow to its maximum

Each year, Arctic sea ice freezes over millions of square miles amid colder temperatures. This 1-minute animation depicts that process using data from the winter of 2022-23.

Journey through Norway's frozen frontier

This 44-minute video takes viewers through the Arctic landscapes of Norway, as they learn about the area's life and challenges. Viewers can observe the wildlife that thrives in this harsh setting—from reindeer and polar bears to red foxes. They...

Learn about endoliths, the polyextremophiles that thrive inside rocks

These organisms include species that live in Antarctica, where they perform photosynthesis using light and water that makes it through pores in sandstone. Others residing in Earth's crust can survive temperatures reaching 60 degrees Celsius (140 degrees Fahrenheit) while generating energy through chemical reactions involving nutrients and gases trapped in rocks.

Excluding water vapor, greenhouse gases make up less than 1% of Earth's atmosphere

Although carbon dioxide, methane, nitrous oxide, ozone, and most fluorinated gases account for only a minority of the planet's greenhouse effect due to their lower concentrations, they are more effective at trapping thermal radiation. While water vapor condenses within two weeks, other greenhouse gases linger in the atmosphere for years on average.

In 2025, UK scientists began studying climate data from a 1.5-million-year-old ice core

The Antarctica sample will be melted and analyzed in Cambridge to learn about prehistoric environmental conditions. Researchers hope the ice core reveals how Earth's glacial cycles shifted dramatically around 800,000 years ago.

Atmospheric greenhouse gases trap thermal energy and make Earth habitable

The moon and Earth are at the same distance from the sun, but the moon experiences large fluctuations in surface temperature because it lacks an atmosphere to insulate it. Gases such as water vapor, ozone, carbon dioxide, and methane can intercept about 90% of the infrared radiation emitted by Earth's surface.

The fragility of the alpine tundra

This article takes readers into Rocky Mountain National Park's Alpine Tundra, an area above the tree line where only specially adapted plants can survive. One such plant is the cushion plant, which avoids strong winds by growing close to the ground...

Billion-year-old Arctic fossils suggest Earth had fungi far earlier than previously thought

Named Ourasphaira giraldae, this new species of fungus, reported in 2019, was found in the Grassy Bay Formation in the Canadian Arctic. It pushed the fossil record of fungi back by about half a billion years since the oldest previously recognized fungi fossils came from the Rhynie chert, a Scottish site that dates back roughly 400 million years. This fungal discovery also suggests that fungi may have occurred on land much earlier than plants, raising questions about what ancient fungi used for nourishment.

How is climate change reshaping the Great Northern Wilderness?

This article focuses on how climate change is drastically altering Kluane National Park in Canada and nearby areas in Alaska. Glaciers are struggling: One large glacier is melting so fast that it has redirected a river's flow, a phenomenon that...

Instabilities in the polar jet stream can bring cold Arctic air southward

The polar jet stream marks the boundary between mid-latitude air and the much colder polar air, which are normally contained by the polar vortex—a ring of strong winds that circles the Arctic around 16 to 50 kilometers (10 to 30 miles) above the Earth's surface. Climate change may be responsible for "blocking patterns" that distort the jet stream, allowing polar air to leak into lower latitudes.

Why parts of the Earth are colder when the planet is closer to the Sun

The Earth orbits the Sun in an elliptical shape, and winter in the Northern Hemisphere occurs when the Earth reaches the point in its orbit closest to the Sun, known as perihelion. The lower temperatures result from the hemisphere tilting away from the Sun.

There may be 74,963 kinds of ice, resulting from water molecules rearranging themselves

The theoretical limit greatly expands the known types of ice, with type Iₕ being the most common on Earth and forming hexagonal crystals. The extreme environments of planets like Uranus and Neptune can create a variety of ice with unique structures and properties, as these conditions can reshape these crystals into new geometries.

What is freezing fog?

Freezing fog is a weather condition in which fog containing supercooled water freezes on contact with objects, forming a layer of ice and possibly dangerous driving conditions. Get the breakdown with this explainer.

Carbon dioxide acts as a 'control knob' for Earth's climate

Although Earth's ice ages were primarily triggered by slow changes in the planet's orbit—known as Milankovitch cycles—these changes do not explain the extreme temperature swings during glacial periods. Carbon dioxide acts as a feedback mechanism, intensifying both cooling during ice ages and warming during their ends by reinforcing the initial changes sparked by orbital shifts.

Glacial ice loss can be determined by listening to escaping bubbles

Glaciers form from the accumulation of layers of snowfall over hundreds to thousands of years, trapping air bubbles that serve as time capsules of atmospheric conditions at the time. When glaciers melt, these bubbles produce a distinctive sound that can be detected by underwater microphones, allowing assessment of melting from a safe distance.

The British Antarctic Survey created a map of what Antarctica would look like if it lost all 27 million cubic kilometers (6.5 million cubic miles) of its ice—enough to fill almost 6,500 Grand Canyons.

Carbon sinks absorb more greenhouse gases than they produce

The largest on Earth are oceans, which capture 25% of all carbon emissions and 90% of excess atmospheric thermal radiation while generating half of the world's oxygen. Wildfires and deforestation have reduced forests' net sink capacity, though fungi are believed to capture and store over a third of global carbon emissions.

Hail forms in freezing temperatures thousands of feet above the ground

Even if surface temperatures are well above freezing during the summer, updrafts during thunderstorms can push raindrops high into the atmosphere, where they can freeze and form hail. Giant hailstones the size of softballs require updrafts of close to 100 mph.