Adding to the problem

Deforestation and the use of fossil fuels are not the only human activities causing climate change. Other aspects of modern life are adding to the problem. Some produce more carbon dioxide, as well as other greenhouse gases such as methane, nitrous oxide, and chlorofluorocarbons (CFCs). These other greenhouse gases are released in much smaller quantities than carbon dioxide, but they have a serious impact because they are much more powerful. A molecule of methane, for example, has the same...

Fossil Fuel Consumption

The main source of all the extra carbon dioxide in the atmosphere is the burning of fossil fuels. These include coal, oil in all its refined forms, and natural gas. All these fuels contain a lot of carbon. This chart shows that the annual consumption of fossil fuels varies by region and by country. The biggest consumers of fossil fuels are the United States, China, and the European Union. Coal produces far more carbon dioxide per unit of energy than the other fuels, so countries that burn a lot...

Checks and Balances

The energy that Earth soaks up from the Sun is more or less balanced by the energy that it radiates out into space, but only in the long term. Short-term imbalances can make the planet colder or warmer. These temperature changes can lead to mass extinctions, like the one that wiped out the dinosaurs 65 million years ago. Once the balance is upset, this can lead to other changes in Earth's climate system, which are called feedbacks. There are two types of feedback. Negative feedbacks resist...

Tidal barrages

A hydroelectric dam can be built across a tidal inlet on the coast. Gates in the dam open to allow water in as the tide rises every day. At high tide the gates are closed, and as the tide falls again, the water behind the barrage is allowed out through turbines linked to electricity generators. Some systems like this tidal plant in France exploit both the incoming and outgoing tide. Tidal barrages produce clean electricity, but they can be extremely damaging to coastal wildlife habitats because...

The Greenhouse Effect

Earth Atmospheric Layers

Earth would be a lifeless ball of rock if it did not have an atmosphere. This is partly because living things rely on the atmosphere to supply them with essential elements such as carbon, nitrogen, and oxygen. Living things also depend on the atmosphere to maintain the temperature that they need to survive. The layers of air that surround the planet act as both sunscreen and insulation, shielding life from the fiercest of the Sun's rays while retaining heat that would otherwise escape back into...

Climate Change

Satellite infrared image of Earth's temperature at night LONDON, NEW YORK, MELBOURNE, MUNICH, AND DELHI Project editor Margaret Hynes Managing editor Camilla Hallinan Managing art editor Owen Peyton Jones Art director Martin Wilson Publishing manager Sunita Gahir Category publisher Andrea Pinnington Picture researcher Sarah amp Roland Smithies DK picture library Lucy Claxton, Rose Horridge, Myriam Megharbi, Emma Shepherd, Romaine Werblow Production editor Hitesh Patel Senior production...

Power for the people

Small Scale Power Generation

Big power plants generating megawatts of electricity are essential for keeping large-scale infrastructure running, but households and small communities can provide some or even all of their own power without using fossil fuels. Some is in the form of electricity, and some in the form of heat energy. A lot of the technology used to produce this local power is still being perfected it is not as efficient as it might be, and it can cost a lot. But its efficiency will improve, and as more people...