Earth keeps getting warmer. Scientists believe this is caused by an increase in something called greenhouse gases.

 

Greenhouse gases collect in the Earth's atmosphere. The atmosphere is a layer of gases that surround the Earth. Carbon dioxide (CO2), methane (CH4), and ozone (O3), are kinds of greenhouse gases.

 

The greenhouse gases allow the sun's light to shine onto Earth's surface. Some of that heat gets reflected. It bounces from the surface of the Earth. Then, the gases trap the heat inside Earth. The gases act like the glass walls of a greenhouse. In other words, they are warming.

 

Animals and Plants Contribute to Greenhouse Gases

Without the greenhouse effect, Earth's average temperature would drop. Now, it is about 57 degrees Fahrenheit (14 degrees Celsius). It could drop to as low as 0 degrees Fahrenheit (minus 18 degrees Celsius). The weather would go from mild to very cold.

 

Some greenhouse gases come from nature. Animals and plants release carbon dioxide when they breathe. Methane is another greenhouse gas. It is released when soil and living things break down. Volcanoes also release greenhouse gases.

 

Factories and Vehicles Can also Be Blamed

The Industrial Revolution happened in the late 1700s and early 1800s. This led to more factories and machines being built. The factories burned fuel and released more greenhouse gases into the atmosphere. 

 

Greenhouse gases almost doubled between 1970 and 2004. 

 

The amount of CO2 in the atmosphere is growing. There is more CO2 now than Earth has seen over the last 650,000 years.

 

Much of the CO2 comes from burning fossil fuels. Cars, trains and planes all burn fossil fuels, such as gasoline. Many electric power plants do as well. 

 

More Gases Lead to Global Warming

Humans also release CO2 into the atmosphere when they cut down forests. Trees contain large amounts of carbon.

 

People add methane to the atmosphere through farming of livestock such as cows. It also happens when we mine for coal

 

Fluorinated gases are also greenhouse gases. Chlorofluorocarbons (CFCs) are one example of these. CFCs are used in refrigerators, air conditioners and aerosol cans. 

 

As greenhouse gases increase, so does Earth's temperature. This rise caused by humans is known as global warming.

 

The Greenhouse Effect and Climate Change

Even small increases in temperatures can have huge effects.

 

Perhaps the biggest effect is that glaciers and ice caps melt faster than usual. The meltwater drains into the oceans. This causes sea levels to rise.

 

Glaciers and ice caps cover about one-tenth of the world's land. If all this ice melted, sea levels would rise about 70 meters (230 feet).

 

Climate scientists say that the world's sea level has risen.

 

Rising sea levels cause flooding in coastal cities. This could force millions of people in lower-lying areas out of their homes.

 

Millions of more people in countries depend on water from melted glaciers. They use it for drinking and watering crops. Losing these glaciers would greatly hurt those countries.

 

Greenhouse gases also cause changes in rain and snow.

 

In the 1900s, rain and snow increased in eastern parts of North and South America. It also increased in Northern Europe, and northern and central Asia. However, it decreased in parts of Africa and southern Asia.

 

As climates change, so do environments. Animals that are used to a certain climate could become threatened. 

 

Many humans depend on predictable rain patterns. This helps them to grow specific crops. If the climate of an area changes, the people there may no longer be able to grow anything. Some of them depend on farming for survival. 

 

What Can We Do?

  • 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.

 

The Greenhouse Effect and our Planet
The greenhouse effect is a vital natural phenomenon, intensified by human activity.
aerosol can
Noun

container of liquid material under high pressure. When released through a small opening, the liquid becomes a spray or foam.

Noun

the art and science of cultivating land for growing crops (farming) or raising livestock (ranching).

Noun

layers of gases surrounding a planet or other celestial body.

carbon
Noun

chemical element with the symbol C, which forms the basis of all known life.

carbon dioxide
Noun

greenhouse gas produced by animals during respiration and used by plants during photosynthesis. Carbon dioxide is also the byproduct of burning fossil fuels.

chlorofluorocarbon (CFC)
Noun

chemical compound mostly used in refrigerants and flame-retardants. Some CFCs have destructive effects on the ozone layer.

climate
Noun

all weather conditions for a given location over a period of time.

Noun

dark, solid fossil fuel mined from the earth.

Noun

edge of land along the sea or other large body of water.

Noun

agricultural produce.

electricity
Noun

set of physical phenomena associated with the presence and flow of electric charge.

environment
Noun

conditions that surround and influence an organism or community.

Noun

process by which liquid water becomes water vapor.

Noun

overflow of a body of water onto land.

fluorinate
Verb

to add or combine with the element fluorine (F).

forest
Noun

ecosystem filled with trees and underbrush.

fossil fuel
Noun

coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

freshwater
Noun

water that is not salty.

gas
Noun

state of matter with no fixed shape that will fill any container uniformly. Gas molecules are in constant, random motion.

Noun

mass of ice that moves slowly over land.

Noun

increase in the average temperature of the Earth's air and oceans.

greenhouse
Noun

building, often made of glass or other clear material, used to help plants grow.

Noun

phenomenon where gases allow sunlight to enter Earth's atmosphere but make it difficult for heat to escape.

greenhouse gas
Noun

gas in the atmosphere, such as carbon dioxide, methane, water vapor, and ozone, that absorbs solar heat reflected by the surface of the Earth, warming the atmosphere.

Noun

environment where an organism lives throughout the year or for shorter periods of time.

hydrochlorofluorocarbon
Noun

greenhouse gas often used as an industrial cooling material.

hydroelectric power
Noun

usable energy generated by moving water converted to electricity.

hydrofluorocarbon
Noun

greenhouse gas often used as an industrial cooling material.

Noun

area of fewer than 50,000 square kilometers (19,000 square miles) covered by ice.

Industrial Revolution
Noun

change in economic and social activities, beginning in the 18th century, brought by the replacement of hand tools with machinery and mass production.

Noun

watering land, usually for agriculture, by artificial means.

landfill
Noun

site where garbage is layered with dirt and other absorbing material to prevent contamination of the surrounding land or water.

livestock
Noun

animals raised for human use.

meltwater
Noun

freshwater that comes from melting snow or ice.

methane
Noun

chemical compound that is the basic ingredient of natural gas.

microbial
Adjective

having to do with very small organisms.

Noun

process of extracting ore from the Earth.

molecule
Noun

smallest physical unit of a substance, consisting of two or more atoms linked together.

Noun

type of fossil fuel made up mostly of the gas methane.

nitrous oxide
Noun

greenhouse gas used in medicine and the manufacture of rockets. Also known as laughing gas or happy gas.

Noun

large body of salt water that covers most of the Earth.

ozone
Noun

form of oxygen that absorbs ultraviolet radiation.

power plant
Noun

industrial facility for the generation of electric energy.

Noun

all forms in which water falls to Earth from the atmosphere.

public transportation
Noun

methods of movement that are available to all community members for a fee, and which follow a fixed route and schedule: buses, subways, trains and ferries.

Noun

liquid precipitation.

recycle
Verb

to clean or process in order to make suitable for reuse.

reflect
Verb

to rebound or return light from a surface.

refrigerant
Noun

substance used to keep materials cool.

respiration
Noun

breathing.

Noun

base level for measuring elevations. Sea level is determined by measurements taken over a 19-year cycle.

snow
Noun

precipitation made of ice crystals.

Noun

land permanently saturated with water and sometimes covered with it.

temperate
Adjective

moderate.

Noun

degree of hotness or coldness measured by a thermometer with a numerical scale.

tropical
Adjective

existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.

vapor
Noun

visible liquid suspended in the air, such as fog.

Noun

an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.