Gases
Around the Earth Trap Heat
by
Alana Ringen, age 9
People
talk about climate change all the time. You can see the effects of it
everywhere you go, but some people don’t really know what it is, or
why it’s happening.
The Earth was formed a long time ago, about 4.5 billion
years ago to be exact. The climate on Earth during its first billion
years was very different than it is today. The sun was cooler, but
the Earth was much warmer because there were higher levels of carbon
dioxide and methane in the atmosphere. These gases are called
greenhouse gases.
These
gases, also known as heat trapping gases, exist naturally in the
atmosphere. They trap heat in the atmosphere to keep Earth warm
enough for plants and animals to live.
When
photosynthesis became common two million years ago, the amount of
greenhouse gases in the atmosphere decreased. During photosynthesis,
plants take carbon dioxide out of the atmosphere and replace it with
oxygen. This process reduced the level of greenhouse gases in the
atmosphere, making Earth’s climate cooler.
For
at least the last 650,000 years, the Earth’s temperature has
increased and decreased in a cyclical pattern. Although the climate
has always experienced these fluctuations, people weren’t around to
cause these changes. Instead, they occurred naturally.
In
the 1900s, however, people started burning coal and other fossil
fuels. People use these fuels to power their homes, factories and
vehicles. This created a lot of pollution and released extra amounts
of gases like carbon dioxide and other greenhouse gases into the
atmosphere. The extra greenhouse gases humans put into the atmosphere
are causing the climate to warm more rapidly than it does during its
natural cycle.
If
humans continue releasing these gases into the atmosphere, the Earth
will get even hotter, and climate change will become more severe.
This could have serious impacts on the environment and society. We
should find ways to reduce the burning of fossil fuels and get rid of
excess greenhouse gases!
[Source:
The Environmental Protection Agency
]
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