Nearly half the oxygen we breathe comes from photosynthetic plankton, not plants

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.

The history of Earth's breathable atmosphere, made possible by photosynthetic bacteria

Between 3.2 billion and 2.8 billion years ago, threadlike microorganisms called cyanobacteria began consuming available water vapor, carbon dioxide, and sunlight to produce oxygen. However, molecules released from Earth's interior by volcanoes consumed this oxygen via chemical reactions, preventing it from accumulating until volcanism had sufficiently decreased about 2.4 billion years ago.

Why the abundance of RuBisCO in photosynthetic cells may come from its inefficiency

Despite pulling about 115 billion tons of carbon dioxide from the atmosphere to build organic molecules each year, the enzyme instead binds oxygen at least one in five times, needlessly costing cells energy. To compensate for this and its processing of no more than 10 molecules per second—versus thousands processed by a typical enzyme—it's become the most abundant enzyme on Earth.

About 99% of Earth's atmosphere is made of nitrogen and oxygen

At 78% and 21% respectively, the two elements are followed by argon with almost 1%. Trace amounts of other molecules, including greenhouse gases such as methane and carbon dioxide, and particulate matter such as dust and pollen, make up the remainder of the atmosphere's contents.

An overview of oxygenic photosynthesis, which releases oxygen from breaking down water

Within the membranes of chloroplasts, electrons in pigments are energized by light and transferred across a series of molecules until they create the energetic NADPH molecule. This transfer also powers a hydrogen pump, which creates an ion imbalance that, when relieved, produces energetic ATP molecules. Outside the membranes, both NADPH and ATP are used to synthesize G3Ps, which are funneled into other metabolic pathways to produce sugars.

The largest river on Earth is actually in the sky

High above the canopy of the Amazon rainforest drifts an airborne river fed by the towering trees below. The trees pull water from their roots into their trunks, pushing any excess water out of their leaves and into the atmosphere as vapor. Watch this six-minute video to learn how.

Brief article explaining why the Amazon rainforest might now produce more carbon dioxide than it absorbs

Climate change and deforestation may have transformed the Amazon rainforest into a net source of planet-warming gases instead of a carbon sink, according to Smithsonian magazine.

Watch a time-lapse from space of photosynthesis across Earth

Using NASA satellite imagery, carbon absorption can be tracked and serves as a proxy for photosynthetic activity on land and in the oceans. Over the course of a year, seasonal changes can be observed as plants become dormant in the fall and active again in the spring.

Imagining if humans could perform photosynthesis and how it would change our anatomy

Since chloroplasts reflect green light, becoming photosynthetic would give our skin a green appearance. Because photosynthesis has efficiencies of only 5% to 9%, and humans burn 2,000 Calories daily compared to about 200 burned by a tree, becoming photosynthetic would also require us to adopt a less active, sun-filled lifestyle.

Why 75% of ocean animals glow

About 75% of ocean creatures can make their own light. It's called bioluminescence—and it all comes down to a special chemical reaction happening inside their bodies.

Plant based milk is good for the planet, but not quite as good for you

Rising in popularity, plant-based milks are a practical alternative for consumers concerned about sustainability and climate change. Plant-based milks, such as oat, almond, rice, and soy milk, generate about one-third of the greenhouse gases and use...

Nonprofits strive to replant the Amazon and slow global warming

This article explores the efforts of nonprofit organizations like Rioterra in reforesting the Brazilian Amazon to mitigate climate change. Their goal is enormous: reforest an area twice the size of Germany, costing over 20 billion dollars. In order...

Ozone protects against the sun's UV radiation and enhances the greenhouse effect

In the stratosphere, trioxygen molecules can absorb harmful ultraviolet radiation from the sun, preventing it from reaching Earth's surface, where it can harm organisms and raise surface temperatures. In the lower atmosphere, ozone acts as a greenhouse gas, trapping thermal radiation.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

How Oceans were formed

Nonprofit organization American Oceans briefly explains the formation of the oceans, which cover over two thirds of Earth’s surface. They were formed by centuries of rain from the condensation of Earth's original gasses.

The Google Doodle honoring Jan Ingenhousz, who discovered oxygenic photosynthesis

Born in 1730, the Dutch scientist expanded on existing knowledge that plants produce and absorb gases in his 1779 paper, which detailed that light was necessary for the biochemical processes that produce oxygen in plant leaves. He also identified that all parts of plants produce carbon dioxide at night.

A breakdown of where water is located on Earth and where it is most used worldwide

About 97% of Earth's water volume is in the oceans, 2% is trapped in polar ice caps and glaciers, and almost all of the remaining 1% is found in groundwater reserves. Roughly 70% of the easily accessible surface water in rivers and lakes—0.01% of all water—is used for agriculture, contributing to 20% of the world's population living in water-scarce areas and 2.1 billion people lacking access to clean drinking water.

Synthetic textiles and tires are the top sources of secondary ocean microplastics

These sources contribute more than 60% of the primary microplastics polluting the oceans, followed by city dust and road markings. City dust is made of pieces of building coatings, synthetic footwear, and other human-made objects that have broken off due to weathering and abrasion.

Photos and descriptions of unique plants found in the Amazon rainforest

It’s the plants that provide homes for the incredible diversity of Amazon animals. Read about 29 of the most fascinating Amazon rainforest plants.

Earth is the only planet in our solar system with fire

And while the sun seems like fire, and other planets have volcanoes, the sun and lava aren't the same thing as fire. To produce fire, a planet needs three ingredients: oxygen, fuel, and heat. No other planet has all three.

Watch students comically portray how plants can detoxify the environment

Through a series of processes that collectively make up phytoremediation, plants can take up pollutants from soil and water through their roots, then break them down, release them as less harmful gases, or store them within their cells. Any plants that sequester heavy metals or other toxins must be removed and managed after the environment is decontaminated.

One-third of the world’s food supply relies on pollinators

By supporting crop production and farmland ecosystems, these animals contribute over $200B to the global economy. A 3% to 5% decrease in this production may result in as many as 427,000 deaths due to nutritional deficiencies.

Space tourism rockets emit up to 100 times more CO₂ per passenger than airplanes

Rocket launches release significant amounts of water vapor, nitrous oxide, and rocket propellants, which generate greenhouse gases and air pollutants. High-altitude emissions can persist for years, affecting the ozone layer.

The world derives more of its energy from oil than from any other resource

Coal and gas are second and third, respectively, in terms of where the bulk of the world’s energy consumption stems from. These interactive charts can help you visualize where the world sources the most of its energy.

Aerial photos of red tide off the Gulf Coast

The toxic algae grows naturally in warmer oceans in small amounts and is typically harmless. With extended warm periods and unusually-high additions of nutrients from run-off, the algae blooms extensively, posing health risks to wildlife and humans...

The US produces far more waste and recycles far less of it than other developed countries

The US represents just 4% of the world’s population, but it produces 12% of global municipal solid waste. In comparison, China and India make up more than 36% of the world’s population and generate 27% of that waste.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

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.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

See the 25 of the best photos of auroras from around the world.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

How the most famous Ebola book, The Hot Zone, which sold 3.5 million copies and was translated into 30 languages, got aspects of the disease so wrong.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.