What is global warming?

Global warming is the heating up of the planet, the globe. It’s also known as climate change.

The Earth is always going through temperature changes. Thousands of years ago, the temperature was very cold and Earth was stuck in an ice age. Now, the temperature is going up. Never before in history has the Earth heated up as quickly as it is now. Some scientists believe humans are the main cause of global warming today.

Earth is surrounded by a layer of gases called the atmosphere. When sunlight hits the Earth, it passes through the atmosphere. Some of the heat from the Sun goes back out into space and some of it is trapped by the gases in the atmosphere. 



The gases that trap the heat from the Sun are called greenhouse gases. Greenhouse gases keep the Earth warm like a greenhouse keeps plants warm. Without these gases, the Earth would be freezing cold and nothing could live on it!

There’s just one problem, the more greenhouse gases there are in the atmosphere, the warmer the Earth becomes!

 

What happens when temperatures rise?

In the last 100 years, the temperature has been getting hotter and hotter. Here’s what happens when the temperature goes up:

  • Glaciers melt making sea levels go up. When sea levels are higher, land by coastlines can end up underwater.
  • Animals migrate or die which interferes with the food chain.
  • The weather goes through extreme changes. Hurricanes, floods and droughts become more common.



 

Did you know?

  • Every time we drive our cars or use electricity, greenhouse gases are released into the air.
  • Since 1990, 20% more carbon dioxide has been released into the atmosphere.
  • Volcanoes can change the temperature of the Earth. When they erupt, huge clouds of ash can block out the light of the Sun and make the Earth cool down. They also let out large amounts of carbon dioxide.
  • When oil, gas and coal are burned they release carbon dioxide into the air. Carbon dioxide is a greenhouse gas.