What is Climate Change?
The phrase is often mentioned in political debates and conversations. But what exactly is it? This article will give an overview of what climate change is and how it is caused.
First, let's define climate!
Let's take a look at our home Seattle:
We can say that on a particular day the precipitation, humidity, temperature, and wind speed were the values listed up above. These values would give us a picture of the weather for that particular day in Seattle. We can also describe the weather of a place by looking at the sunshine, cloud cover, flooding, thunderstorms, atmospheric pressure and more (NASA).
However, weather is not the same as climate! Weather
is the condition of an atmosphere over a short period of
time (days, weeks, or months). Climate is the average
values of the weather of a place over a long period of time, usually 30 years or more. You can think of the climate of a location as what you would normally expect the weather to be like on a certain day (NASA). For example, in the fall we would normally expect Seattle to look like the picture to the right. What would you say the climate of Seattle is like?
Okay, so then what is climate change?
When talking about climate change it is important to note that our earth's climate has been naturally changing over the course of thousands and millions of years. Just an example of the naturally changing climate is the Little Ice Age, which was a period of time from the mid 14th century to mid 19th century when mean annual temperatures in the northern hemisphere dropped by 0.6°C (Britannica). The graph below from the National Oceanic and Atmospheric Association shows how the temperature of the earth has changed over the past 1000 years.
The climate change you hear in the news is human caused climate change.
Unlike natural climate change, human caused climate change, or anthropogenic climate change, is the alteration of the earth's natural atmospheric processes by human activities and industries.
The main ways humans contribute to climate change are:
Burning fossil fuels, like coal, for energy
Raising livestock, especially cattle
and there are more...
When we burn fossil fuels, an important bi-product is produced: carbon dioxide gas. When we raise cattle another important bi-product is produced from their fart: methane gas (National Geographic).
Carbon dioxide and methane are both known as greenhouse gases. They help retain the sun's heat, effectively warming up our planet.
Heat from the sun
Some heat does
Not to scale model of earth's atmosphere
Most of the heat from the sun
is retained inside earth's atmosphere
because of the greenhouse gases.
With a massive increase in world population and a surging demand for energy, fossil fuels are being burned at an intense rate. This in turn increases the amount of carbon dioxide in the atmosphere, warming up our planet. Similarly, with more people eating meat, cattle production increases. This increases the amount of methane gas in the atmosphere, also warming our climate and contributing to climate change.
According to the UN, in the year 2050 the world population is expected to hit 10 billion. Imagine all those people and the resources they need. Now imagine the carbon dioxide produced in order to support everybody.
Deforestation also contributes to climate change.
Trees and plants play a central role in taking in carbon dioxide from the atmosphere during photosynthesis. As we clear out entire forests, the earth's ability to control carbon dioxide levels is weakened. As a result, carbon dioxide levels continue to increase.
Okay so what if the earth gets hotter?
Well one devastating consequence of climate change is the rising of sea level. The hotter global temperatures melt the glacier ice in the Arctic. According to the United Nations, glacier melting will cause sea levels to rise about 3 feet by the end of this century.
But of course there are tons more negative consequences of climate change... Click the button below to learn more about the devastating impacts of climate change.
An Inconvenient Sequel: Truth to Power by Al Gore
intergovernmental panel on climate change: