The Greenhouse Effect and Climate Change
Even slight increases in average global temperatures can have huge effects. Perhaps the biggest, most obvious effect is that glaciers and ice caps melt faster than usual. The meltwater drains into the oceans, causing sea levels to rise.
Glaciers and ice caps cover about 10 percent of the world’s landmasses. They hold about 75 percent of the world’s freshwater. If all of this ice melted, sea levels would rise by about 70 meters (230 feet). The Intergovernmental Panel on Climate Change states that the global sea level rose about 1.8 millimeters per year from 1961 to 1993, and 3.1 millimeters per year since 1993.
Rising sea levels could flood coastal cities, displacing millions of people in low-lying areas such as Bangladesh, the U.S. state of Florida, and the Netherlands. Millions more people in countries like Bolivia, Peru, and India depend on glacial meltwater for drinking, irrigation, and hydroelectric power. Rapid loss of these glaciers would devastate those countries.
Greenhouse gas emissions affect more than just temperature. Another effect involves changes in precipitation, such as rain and snow. Over the course of the 20th century, precipitation increased in eastern parts of North and South America, northern Europe, and northern and central Asia. However, it has decreased in parts of Africa, the Mediterranean, and southern Asia.
As climates change, so do the habitats for living things. Animals that are adapted to a certain climate may become threatened. Many human societies depend on specific crops for food, clothing, and trade. If the climate of an area changes, the people who live there may no longer be able to grow the crops they depend on for survival. Some scientists also worry that tropical diseases will expand their ranges into more temperate regions if the temperatures of those areas increase.
Most climate scientists agree that we must reduce the amount of greenhouse gases released into the atmosphere. There are lots of ways to do this, including:
Drive less. Use public transportation, carpool, walk, or ride a bike.
Fly less. Airplanes produce huge amounts of greenhouse gas emissions.
Reduce, reuse, and recycle.
Plant a tree. Trees absorb carbon dioxide, keeping it out of the atmosphere.
Use less electricity.
Eat less meat. Cows are one of the biggest methane producers.
Support alternative energy sources that don’t burn fossil fuels.