Greenhouse gases absorb heat from the Sun help warm the planet

Greenhouse gases absorb heat from the Sun help warm the planet, which makes it possible for plants and animals to live. Most greenhouse gases are a natural of life. For example, humans out small amounts of carbon dioxide into the air. But human activities have caused some gases to build up too much. Many scientists believe this increase in greenhouse is causing global warming.

What are greenhouse gases?

Carbon dioxide (CO₂) makes up more than 99 percent of the greenhouse gases in Earth’s atmosphere. The remaining 0.6 percent contains methane, nitrous oxide, ozone, and halocarbons.

The carbon cycle

Carbon flows between land, sea and sky in a natural cycle. But human activities are adding so much carbon to the atmosphere that these natural cycles have been thrown off balance. 

Plant-atmosphere cycle

As they grow, plants trap and store huge amounts of carbon. They release only a little as they decay. This keeps CO₂ levels in Earth’s atmosphere stable

The greenhouse effect

The greenhouse effect is a natural process discovered in 1896. It has kept our planet warm enough to support life for billions of years. But as the amount of greenhouse gases increases, more heat is trapped in the atmosphere. The natural process has sped up and Earth is getting hotter.

OUT Sky

The sky above us seems huge, but if Earth were the size of an onion, its atmosphere would only be as thick as the onion’s papery skin. The atmosphere can be divided into five parts.

Life in a greenhouse

Just as the glass of a greenhouse lets in light and traps warm air inside, the greenhouse gases in Earth’s atmosphere let sunlight pass through  and trap heat inside.

Solar energy Only about half of the Sun’s energy makes it to Earth’s surface. The rest is bounced back or trapped by clouds and the atmosphere itself.