Heat from the Sun supplies our planet with warmth. But over the past 150 years the amount of heat that is trapped by Earth has increased, causing global warming.
Click on image for full size
Courtesy of USGS Astrogeology Research Program
What Controls the Climate?
Climate can change if there is a change in the amount of solar energy that gets to Earth. A change in the solar cycle can impact climate. The effect is too small to be the reason that global warming that is happening now. Over thousands of years, changes in the way Earth orbits the Sun can cause big changes in climate too.
When volcanoes erupt they spew more than lava and ash. They also release tiny particles so small that you can’t even see them. These particles get into the stratosphere and reflect solar radiation away from Earth. This shades the planet, causes cooling. After a year or two the little particles fall out of the air and the climate warms up again.
Greenhouse gases trap heat through a process called the greenhouse effect. Greenhouse gases are a natural part of the atmosphere. But the amount of them has grown over the past 150 years as fossil fuels are burned.
Snow and Ice
Because snow and ice are light in color, they have a high albedo. That means they reflect most of the solar energy that gets to them back out to space. When snow and ice melt as Earth’s climate warms, less energy is reflected and this causes even more warming.
There are also other parts of our planet that have an impact on climate too. For example, scientists are studying the impact of clouds and aerosols on climate.
Last modified June 11, 2008 by Lisa Gardiner.
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
How do you know to pack your bathing suit and sunhat for a trip to a tropical island or pack warm sweaters and coats for a trip to Alaska? If you know a little about regional climates, then you know what...more
Did you know that the Sun has spots on it? The number of spots on the Sun changes. Sometimes there are lots of spots and other times there few spots. Scientists have wondered for a long time if the number...more
Ash is formed as a volcano erupts when rocks made by the volcano blow apart into millions of tiny pieces. The rocks are still very hot, because they just formed from lava. If the hot rocks come into contact...more
When you look up at the sky, you are looking at more than just air. There are also billions of tiny bits of solid and liquid floating in the air. These tiny particles are called aerosols or particulates....more
Only a tiny amount of the gases in Earth’s atmosphere are greenhouse gases. But they have a huge effect on climate. There are several different types of greenhouse gases, but they all have something in...more
Not all of the energy from the Sun that arrives at Earth can leave easily. After being transformed into heat, it can become trapped by certain gases in the air. This is a natural process called the greenhouse...more
This picture was taken from high above our planet. Looking at the Earth from very far away like this we can see that some parts of our planet look light in color, and some parts look dark. The color of...more