How does Earth maintain a constant level of oxygen?

It doesn’t! The oxygen level of the planet has varied quite dramatically in the last 500 million years. It was 35 per cent during the Carboniferous period, around 300 million years ago; as the climate, cooled and land plants died off, oxygen fell to as low as 12 per cent by the beginning of the Triassic. Back then, the air at sea level would have felt thinner than at the top of the Alps today.

Burning fossil fuels has reduced oxygen levels very slightly – about 0.057 per cent over the last 30 years. Deforestation only has a small effect because when rainforest is cut down, other plants are usually grown in its place. But it’s marine phytoplankton (plant plankton), rather than trees, that produces about 75 per cent of atmospheric oxygen. Global warming will have a significant impact on phytoplankton, which is a much more serious threat to oxygen levels.

Comments

Most visited

From Confusion to Clarity: How One Study Method Changed Everything

Rohan was an average student—hardworking, but not systematic. His days were filled with long study hours, underlined textbooks, and endless rereading. Yet, when exams came, his mind went blank. Concepts slipped away, and confidence followed. Preparing for NEET , the pressure was immense. Everyone around him seemed to know what to study and how to study—except him. One day, his teacher gave him a simple suggestion: “Don’t study more. Study smarter . Follow the PQRST method.” Skeptical but desperate, Rohan decided to trust the process. Weeks turned into months. His reading became purposeful, his revision sharper, and his confidence stronger. When results were declared, Rohan didn’t just clear NEET—he cracked it with clarity, not chaos. The difference wasn’t intelligence. It was method . The PQRST Study Method: A Smart Way to Learn The PQRST method is a scientifically proven study strategy that promotes active learning , deep understanding, and long-term memory rete...

Oyilattam: The Graceful Tamil Folk Dance of Rhythmic Movements

Introduction Oyilattam , a vibrant and energetic folk dance from Tamil Nadu, is a mesmerizing art form that blends rhythmic movements, colorful costumes, and traditional music. The word “Oyil” means grace or beauty , and “Attam” means dance —together, they describe a performance that celebrates elegance and cultural pride. Often showcased during festivals and community gatherings, Oyilattam is not just entertainment—it’s a living expression of Tamil heritage and unity. 🌿 Origins and Cultural Significance Oyilattam traces its roots to rural Tamil Nadu, where it was traditionally performed by men during harvest festivals, temple rituals, and even to mark victories in battle. Over the years, women too began participating, enriching the art form with new layers of expression and vibrancy. This dance carries deep cultural meaning, symbolizing unity, valor, and devotion . It is most commonly performed during: Pongal – the harvest festival of Tamil Nadu 🌾 Temple festivals ...

Old Rock Day : Exploring Earth’s Ancient Stories Written in Stone (January 7)

Old Rock Day Exploring Earth’s Ancient Stories Written in Stone Introduction Old Rock Day , observed every year on 7th January , celebrates rocks, fossils, and the ancient geological history of our planet. Though it may sound light-hearted, the day carries deep scientific significance—rocks are the oldest storytellers on Earth, preserving evidence of planetary formation, climate change, and the evolution of life. Old Rock Day invites us to slow down and appreciate the quiet witnesses of deep time beneath our feet. Why Rocks Matter Rocks are fundamental to understanding Earth’s history. They help scientists: Determine the age of the planet Study past climates and environments Understand tectonic movements Discover fossils and early life forms Identify natural resources Every rock carries a record of processes that occurred millions—or even billions—of years ago. Types of Rocks and Their Stories There are three main types of rocks: Igneous rocks – Formed from cooled magma or lava,...

Search This Blog