Precipitation can make a day seem gloomy but it is an important part of a healthy climate COOL STEM CAREERS CLIMATE SCIENTIST 2 1 S T C E N T U R Y S K I L L S L I B R A R Y CHAPTER ONE CHANGING CLIMATES Walt sighed as he looked out the window and saw the heavy raindrops splattering on the sidewalk All it ever does is rain he complained Walt’s dad looked up from his laptop computer The weather forecast says the rain might finally clear up in a few days he said
I wish there were more sunny days so I could go outside Walt answered I’m bored of staying inside all the time Sorry said Walt’s dad That’s just the climate we live in Be glad you don’t live in a place where it never rains at all Why Walt asked That sounds great I could go outside and play every day Yes but you might not have any water to drink or food to eat replied Walt’s dad You might also be hot all of the time Climate is about more than just how the weather feels when you go outside Climate describes the conditions of the atmosphere such as precipitation and temperature in an area over a long period of time Wind speeds and humidity are also part of an area’s climate Measurements of these conditions over a shorter period of time are known as weather Weather is usually measured by the hour or day Climates on the other hand are often measured over periods of tens hundreds or even thousands of years An area’s climate has a major effect on everything in that area Atmospheric conditions determine which plants and animals survive Some places that are too hot or too dry for one species might be perfect for another Climate also affects an area’s soil and rocks These determine the types of structures that are built in an area or whether farmers can grow crops
Volcanic eruptions and other natural events play a major role in the climate COOL STEM CAREERS CLIMATE SCIENTIST 2 1 S T C E N T U R Y S K I L L S L I B R A R Y Likewise Earth’s physical features and life-forms can affect climate For example trees and other green plants release a gas called oxygen into the air The plants absorb and store a gas called carbon dioxide Drastic changes in the number of green plants can make a difference in the amounts of these gases in the air over an extended period of time Volcanic eruptions release dust and many different gases into the air This also makes a difference in the surrounding atmosphere
Forces located outside Earth’s atmosphere can affect cli mate too For example the Sun provides Earth with light and heat This star has been growing brighter ever since it formed around 4 5 billion years ago This means that on average Earth’s global climate has become warmer over time The Sun also experiences smaller changes over shorter periods of time As the Sun’s energy increases and decreases it affects Earth’s climate in a variety of ways It might seem like a region’s climate doesn’t change very much The Arctic is always cold and the deserts of the southwestern United States are always dry and warm How ever climates are actually changing all the time This change usually happens on a very small scale For example a certain area might be slightly warmer on average one summer than the previous summer That summer might have had higher temperatures than the one before it and so on Or perhaps the average summer temperatures for the past 100 years were only a little bit higher than the previous 100 years Over a very long period these changes add up to something much more noticeable A certain amount of climate change is natural However these changes can be sped up or slowed down by human activities One example is the role humans have played in increasing the greenhouse effect The greenhouse effect describes the way certain gases in Earth’s atmosphere such
