Our World

Articles about our world, planet earth: its evolution, biogeochemical cycles, planetary subsystems, atmosphere (inc. ozone layer), biosphere (life), hydrosphere (oceans) & lithosphere (rocks). And The Anthropocene.

Fukushima Nuclear Disaster

What is the Anthropocene Epoch?

Worldwide pollution, the reckless exploitation of natural resources, the extinction of animals, and the over-consumption of fossil fuels aka global warming, are all hallmarks of the Anthropocene. We are living in an epoch of environmental & ecological disasters.

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Deep Mangrove Tree Roots

Which is the Largest Carbon Reservoir?

Which carbon reservoir is the biggest? To answer this, we explain how much carbon is stored in the Earth’s crust, the deep ocean, the atmosphere, and in plants and soils? We also examine how human activities have affected carbon sinks, and explain the main features of the fast and slow carbon cycles.

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Picture of Rainforest Jungle

The Oxygen Cycle: Controlled by Plants

We explain the importance of oxygen, where it comes from, where it is found, and how (and in what form) it circulates through the different reservoirs on Earth. In the process, we explain both the fast and slow oxygen cycle and examine how they are affected by climate change.

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Coal Fired Power Station

The Sulfur Cycle: A Simple Guide

We explain the 4 steps of the Sulfur Cycle as well as its impact on the environment. In particular we look at the pollution effects of acid rain (sulfur dioxide + water) – and show how chemical weathering of rocks by sulfuric acid rain releases carbon dioxide into the air, thus adding to global warming.

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Greenhouse gases are invisible but they remain a serious threat to our climate

Biogeochemical Cycles Explained

We explain the routes and importance of the main biogeochemical pathways (e.g. the carbon cycle, the nitrogen cycle) through the Earth’s atmosphere, biosphere, hydrosphere, pedosphere and lithosphere.

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The Phosphorus Cycle: The Slow Pathway

Phosphorus is essential for plant and animal growth, as well as the health of microorganisms in the soil. We plot the 4 main steps of the phosphorus cycle on land and sea. We also look at how the use of phosphorus-based fertilizers and other agro-chemicals is causing ecological problems, such as eutrophication of freshwater systems, as well as hypoxic zones in estuarine and coastal areas.

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Corn with chlorosis from lack of nitrogen

The Nitrogen Cycle: How Does It Work?

We explain the nitrogen cycle on land and sea, showing how processes like fixation, nitrification, denitrification and ammonification convert nitrogen into a usable form. We also look at how the over-use of nitrogen-based fertilizers has altered the global nitrogen pathway, causing a cascade of adverse effects including eutrophication, an increase in nitrous oxide emissions, loss of soil nutrients, increased acidification of soils and streams, damage to estuarine ecosystems, and a marked increase in air pollution.

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Troposphere Explained

What Is The Troposphere?

The lower atmosphere, which scientists refer to as the troposphere, is where greenhouse gases trap heat trying to escape from the Earth’s surface, thus causing global warming. The troposphere contains 99 percent of Earth’s water vapor, and is where all our weather happens, including regional weather cycles like the El-Nino-Southern Oscillation. The troposphere is also where ground-level ozone forms smog.

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What The Atmosphere Looks Like

Earth’s Atmosphere Explained

We explain the main layers of Earth’s atmosphere – including the troposphere, stratosphere, thermosphere, exosphere and mesosphere – plus their chemical constituents and evolution. We explain how the atmosphere is connected to climate change, and look at the main greenhouse gases and other pollutants that are present. We examine how it evolved and how it compares with Venus and Mars.

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Fisherman catches fish in coral reefs

What Is The Hydrosphere?

The hydrosphere is the water (H2O) component of Planet Earth. We explain how it’s affected by climate change and vice versa. We also describe how the water cycle works and how it moves H2O around the planet. We also detail how pollution, eutrophication, ocean warming, and acidification have caused serious problems for marine ecosystems and the health of the seas.

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Planet Earth from Space

Planet Earth: Facts And Information

We explain the origins, structure, chemical composition, tectonic and volcanic movements, and biogeochemical cycles of Planet Earth, plus its population, food, energy and climate. As far as climate change goes, the most important thing to remember is: There is no Planet B. If we lose Earth, we lose everything.

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San Andreas Fault Aerial View

What Is The Lithosphere?

The lithosphere is the rigid, solid outer layer of the Earth. We explain its structure and composition, its tectonic make-up and its lithification of carbon and other chemicals.

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Pedosphere Cliff Earth

The Pedosphere: Earth’s Soil & Earth

We investigate the important layer of soil, dust, stones, sand, and silt which covers the Earth’s surface. Known as the pedosphere, its soils nourish and support plants, the wonderful oxygen providers without which human life would be impossible. We also explain the related disciplines of pedology, edaphology and pedometrics.

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The Water Cycle Explained

The water cycle is a critical component of Earth’s climate system. We explain the 3 main stages of the cycle, how it helps to regulate global climate, and how in turn it is being affected by climate change.

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Picture Of The Ozone Layer

Ozone Layer In The Stratosphere

We explain the hole in the ozone layer and the damage caused by chlorofluorocarbons (CFCs) and other ozone depleting substances (ODS), in line with the Rowland-Molina Hypothesis. Thanks to the Montreal Protocol, ozone depletion is improving.

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Carbon Cycle Explained

The Carbon Cycle: How Does It Work?

We explain all the major processes of the carbon cycle such as photosynthesis, chemical weathering and lithification of carboniferous rock, as well as the difference between carbon sources, sinks and reservoirs.

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Information & Facts about Our World

• The Big Bang, or formation of the Universe happened about 13.8 billion years ago. The Sun formed 4.6 billion years ago and Planet Earth about 4.54 billion years ago. 

• Earth orbits the sun once every 365.25 days. As we set our calendar year to 365 days, we add an extra day every 4 years to settle the difference. 

• Earth hurtles through space at an average speed of 29.6 km (18.5 miles) a second.  

• Our planet is not as big as you might think. It only has a diameter of 13,000 km (8,000 miles). 

• Earth’s core consists of 88.8 percent iron, 5.8 percent nickel, 4.5 percent sulfur and less than 1 percent other stuff, including oxygen.  

• Earth’s atmosphere is about 480 km (300 miles) thick. It contains 5 main layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.  

• Ozone is a naturally occurring gas that resides in our atmosphere, occurring mainly in the lower stratosphere. It is important because it protects us from ultraviolet solar radiation, which can cause skin cancer and eye damage. 

• When Krakatoa volcano erupted on August 27, 1883, it caused the largest volcanic tsunami in history. It was formed in less than a minute after the eruption, and grew to be 40 meters tall. It is estimated to have killed over 36,000 people.