What is Climate Change?

Polar Bear

You may have heard a lot about climate change. Will the ice caps and glaciers all melt? Will the sea level rise? Will our weather change? Is climate change the biggest environmental problem facing our planet today? If you'd like to find out more, check out some of these questions...

What is the Climate?

Climate is the average pattern of weather, over many years, for a particular area. This could be a region like Northern Ireland, or the United Kingdom, or Europe. Climate is not the same as weather - the weather is what you notice each day – such as sunshine, rain or wind.

What is Climate Change?

The climate of the Earth is always changing. In the past the climate has changed as a result of natural causes. For example, after a volcano has erupted, large quantities of dust are blown high into the atmosphere (the air around the Earth). That reduces the amount of sunshine reaching the Earth's surface.

But the words 'climate change' are usually used to mean changes in our climate, which have been seen since the start of the last century (the year 1900). Scientists believe the changes they have seen over this time are mainly because of human behaviour, rather than natural changes.

Climate change is caused by something known as the "greenhouse effect". A greenhouse (or glasshouse) is good for growing plants because it traps heat inside and stays hotter than the air around it. The Earth's atmosphere behaves like a gigantic greenhouse, trapping some of the warmth of the sun. This is called the natural greenhouse effect. Without it, the earth would be much too cold to support all the different kinds of plants and animals that live here.

The problem is that human activity is causing a greater warming of the Earth. This is because the gases released when we burn fuels are changing the atmosphere.

What Causes Climate Change?

Scientists think that climate change is being caused mainly by “greenhouse gases” that we release when we burn fuels (for example, to heat our homes, generate electricity or power industry). Humans have been using energy in far greater quantities since the start of the last century (the year 1900), than they ever did before.

When fossil fuels like coal, gas, oil, or petrol are burnt they create a gas called carbon dioxide. Carbon dioxide makes the greenhouse effect stronger. As a result, more of the sun's heat gets trapped in the atmosphere and the planet warms up. This is what causes climate change. If it continues, it will have a big effect on climates and weather systems all over the world!

Global warming is often described as an anthropogenic process, which simply means "humans caused it".

There are six important greenhouse gases, but carbon dioxide is the most important of them all, because we produce so much of it.

Another very important greenhouse gas is called methane. This is made inside cows and sheep, by the bacteria in their insides. It comes out when they burp!

Do we need to worry?

Scientists predict that climate change will affect much of our world. Many scientists and politicians believe that climate change is a threat greater than anything humans have faced in recent history. Unless we tackle the problem soon, it could cause serious problems, by making the climate much more unpredictable. This could make it much harder to grow enough food for everyone, especially in the developing countries where many people are already poor. Some types of animals and plants could become extinct.

Can we stop Climate Change?

Most climate experts think we need to act quickly to reduce the amount of greenhouse gases that humans are releasing into the atmosphere. We will probably be unable to stop the effects of climate change completely, but we might be able to limit them. To do this we all need to think about the energy that we use in our everyday lives, and try to use less.

No one can do everything, but if everyone does something to reduce the amount of energy we use, we have a chance to limit the effects of climate change. Is there something that you or your family could do to help make a difference?