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 effect as 25 molecules of carbon dioxide. Soot and other cloudy forms of air pollution also affect the climate by reflecting or absorbing sunlight, causing cooling as well as warming.

CATTLE RANCHING

Our appetite for beef has caused a big increase in cattle ranching, especially in the tropics. But cows produce a lot of methane gas as they digest their food, releasing up to 98,420,000 tons worldwide each year.

RICE GROWING

About 10-15 percent of total global methane emissions come from rice fields. Microbes in the wet soil of flooded paddy fields absorb carbon released by rice plants and turn it into methane, which then seeps into the atmosphere.

Beef burger

CEMENT AND CARBON

Cement production plants like this one make cement from limestone, in a process that turns the rock into calcium oxide and carbon dioxide. It involves pulverizing the limestone and heating it to about 2,640°F (1,450°C), which uses a lot of fuel. Cement is very heavy, so transporting it also uses a lot of fuel. Altogether, producing and shipping each bag of cement releases roughly the same weight of carbon dioxide into the atmosphere.

Plastic and metal do not rot down

LANDFILL

Developed countries generate immense quantities of garbage. A lot of it gets burned, releasing carbon dioxide and other, more noxious gases. But a lot more is buried in "landfill sites"where the normal decay process is inhibited by lack of air. Instead, the food waste and other organic remains are broken down by bacteria that do not need oxygen. These return carbon to the air in the form of methane, which is an extremely potent greenhouse gas—so even burying garbage is helping to cause global warming.

Plastic and metal do not rot down

NITROUS OXIDE

This is a relatively scarce, but extremely potent gas, about 300 times as powerful as carbon dioxide. While it is produced naturally by bacteria in the soil, exposed soil may release twice the usual amount. It is also released from the artificial fertilizer that farmers spread on their fields.

. Trucks collect garbage from

Fridges are degassed before being scrapped

CHLOROFLUOROCARBONS (CFCs) A variety of artificial gases are now known to be potent greenhouse gases. They include the CFCs that were once used as refrigerants in domestic fridges. When old fridges are discarded, they must have the gas carefully removed to stop it from escaping into the atmosphere.

AEROSOLS

Some forms of air pollution create clouds of small particles known as aerosols. These can reflect or absorb sunlight and reduce its power. This has reduced the impact of the human-enhanced greenhouse effect over recent decades. But aerosols do not stay airborne for long, so reducing air pollution could actually accelerate warming.

. Trucks collect garbage from

GOES-12

WEATHER SATELLITE

Launched in July 2001, the GOES-12 environmental satellite is one of many orbiting spacecraft equipped with remote sensors for monitoring weather conditions in the lower atmosphere, 22,370 miles (36,000 km) below the satellite.

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