Climate is the pattern of weather a place gets over a long period of time, usually 30 years or more. If weather is what’s happening outside your window right now, climate is what you’d expect to happen based on where you live. A desert climate means you can expect hot, dry days most of the year. A polar climate means you can expect freezing cold. Understanding climate helps explain why different parts of the world look so different and why certain plants and animals live where they do.
Weather vs. Climate
Weather changes from hour to hour and day to day. It’s the rain that catches you without an umbrella, the surprise snow day, or the sunny afternoon nobody predicted. Climate is the bigger picture. Scientists figure out a place’s climate by averaging things like temperature, rainfall, humidity, wind, and sunshine over 30 years. These averages are called “Climate Normals,” and they tell us what’s typical for a location.
Here’s a simple way to remember it: climate is what you expect, weather is what you actually get. You expect summers in Arizona to be scorching hot. That’s climate. But one particular July afternoon might bring a thunderstorm. That’s weather.
The Five Main Climate Zones
Earth has five general climate zones, and each one creates a completely different world for the people, animals, and plants living there.
- Tropical: Warm all year round with no real winter. Think rainforests and places near the equator.
- Subtropical: Still warm, but with a wider range of temperatures than tropical areas. Parts of the southern United States and Mediterranean countries fit here.
- Temperate: Warm summers and cold winters, with four distinct seasons. Much of Europe, the northeastern United States, and parts of China have temperate climates.
- Polar: Extremely cold year-round. The Arctic and Antarctic are polar climates.
- Highland: Found in mountainous areas, where temperatures can swing dramatically between day and night. The higher you go, the colder it gets.
What Shapes a Place’s Climate
Three big factors determine what kind of climate a place has: how far it is from the equator, how high above sea level it sits, and how close it is to the ocean.
Distance from the equator (called latitude) is the single most important factor. The equator gets the most direct sunlight, so places near it are the warmest. As you move toward the North or South Pole, average temperatures drop steadily. That’s why Canada is colder than Mexico even though they’re on the same continent.
Elevation matters just as much in some places. Air cools as you go higher, so a mountain in the tropics can actually have polar-like temperatures at its peak. That’s why you can find snow-capped mountains near the equator in places like Ecuador and Kenya.
Oceans act like giant temperature regulators. Water heats up and cools down much more slowly than land, so cities near the coast tend to have milder winters and cooler summers compared to cities far inland. San Francisco stays cool in summer while Sacramento, just 90 miles east, bakes in the heat. The ocean is the reason.
Earth’s Heat-Trapping Blanket
Earth’s atmosphere works like a blanket wrapped around the planet. Gases in the atmosphere, especially carbon dioxide, trap some of the sun’s heat and keep Earth warm enough for life. Without this natural blanket, our planet would be frozen.
The problem is that burning fossil fuels like coal, oil, and natural gas adds extra carbon dioxide to the atmosphere. It’s like making the blanket thicker and thicker. The thicker the blanket gets, the more heat gets trapped underneath and the harder it becomes for that heat to escape back into space. Right now, carbon dioxide levels in the atmosphere are around 428 parts per million, far higher than at any point in hundreds of thousands of years.
How Climate Is Changing
Earth’s average temperature has risen by about 2 degrees Fahrenheit (roughly 1 degree Celsius) since the 1850s. That might sound tiny, but it represents an enormous amount of extra heat energy circulating through the oceans, ice, and air. Since 1975, the warming has sped up to more than three times the earlier rate.
That extra warmth is already changing the natural world. Plants are blooming earlier in the year, which throws off the timing for pollinators that depend on those flowers for food. Brook trout, which need cold streams, struggle to compete with other fish species as waters warm. The wood thrush, a songbird that migrates from Central America to the eastern United States each summer, faces shrinking habitat as its usual breeding grounds grow too warm. These birds must fly farther north to find suitable homes, and the fruits and insects they rely on for fuel during migration may not be available at the right time.
What Kids Can Do
Small everyday choices add up when millions of people make them. Here are practical things you can start doing right away:
- Turn off lights and electronics when you leave a room. Power plants burn fuel to make electricity, so using less electricity means less carbon dioxide in the air.
- Walk or bike short distances instead of riding in a car. It’s good for the planet and good for your body.
- Cut down on food waste. When food gets thrown away and rots in a landfill, it releases heat-trapping gases. Take only what you’ll eat.
- Repair or reuse things instead of tossing them. Making new stuff takes energy, so keeping things in use longer helps.
- Sort your waste. Separating paper, plastic, glass, and metal for recycling keeps materials out of landfills and reduces the need to pull new resources from the earth.
Learning about climate is itself one of the most powerful things you can do. The more you understand how Earth’s systems work, the better equipped you are to protect them.