What is climate change?
Submitted by: Wilson
Grade level: 11
Answered by: Kayla Burgher
In the American west, the wildfire season is longer and more extreme than ever before. Polar bears in the Arctic struggle to find food as their icy landscape melts. Across the world, people are facing record-breaking heat waves. Storms are becoming stronger and more dangerous. All these things are happening because Earth’s climate is changing. But what is exactly is climate change?
Weather vs. climate
Before we can talk about climate change, we first need to talk about a topic that is confusing to many people: what is the difference between weather and climate?
Weather is what is happening in our atmosphere right now or in the next few days. We say the weather is hot or cold, rainy or sunny, windy or calm. The weather can change fast, and it’s often difficult to predict with accuracy. Think of a sudden afternoon thunderstorm that you didn’t expect. Or the first snowstorm you look forward to every year but are never sure when exactly it will happen. You might also look at a weather app to see the daily high and low temperatures. These are all examples of weather.
Climate, on the other hand, refers to the typical temperature and weather patterns in a place. Imagine a desert, which has a hot and dry climate, or a rainforest with a rainy and humid climate. Each place has a predictable climate, with similar temperatures and amounts of rainfall from year to year. What is the climate of the place you live? You might live in a temperate climate, with warm, humid summers and relatively mild winters. Or perhaps you live in a hot and dry desert climate.
What is climate change?
Climate change happens when there are big, lasting shifts in the usual climate. Unlike day-to-day changes or seasonal shifts, climate change happens slowly. It can take many decades, centuries, or even millions of years for the climate to change. There are two types of climate change: natural and human-driven.
Natural climate change
Earth’s climate has always changed naturally. For example, over the past 450,000 years, the Earth has repeatedly cycled through cold and warm periods. During the cold glacial periods, temperatures drop and ice sheets extend from the poles. When temperatures warm, ice retreats towards the poles. We call this an interglacial period.
The most recent glacial period (usually called “The Ice Age”), was at its maximum around 20,000 years ago. Ice covered much of North America and Europe. The Earth was a very cold and dry place. Around 11,000 years ago, the temperatures rose and the next interglacial phase began. Today, we are still in this warmer interglacial climate.
These natural shifts in Earth’s climate are mainly caused by changes in the Earth’s orbit. For example, there are predictable shifts in the Earth’s distance from the sun and how much the Earth tilts. Ocean currents, volcanoes, and other natural events can also impact the climate.
Human-driven climate change
Today, however, climate change is happening much faster than expected. The Earth is warming up, changing the usual weather patterns we expect to see. This is mainly due to humans burning fossil fuels, like oil, coal, and gasoline. Burning fossil fuels releases greenhouse gases into the air. These greenhouse gases trap heat in the atmosphere that would otherwise escape into space. This raises Earth’s temperature.
We are now starting to see the effects of human-caused climate change. Recently, Europe and many cities in the United States have seen deadly, record-breaking heat waves. Hurricanes in the Atlantic are becoming more common and more damaging. Ice sheets are melting rapidly, which causes sea level to rise and flooding to intensify. These impacts and more are only going to get worse if humans do not make efforts to slow climate change.
Sources
https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/ice-ages-what-are-they-and-what-causes-them
https://www.climate.gov/news-features/climate-qa/hasnt-earth-warmed-and-cooled-naturally-throughout-history
https://www.nature.com/articles/d41586-023-03523-3
https://science.nasa.gov/climate-change/evidence
https://www.ces.fau.edu/nasa/module-4/causes-2.php
https://thesciencebehindit.org/how-is-earths-climate-changing
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