4 Chapter 1 WHAT IS CLIMATE CHANGE Look outside What is the weather like today Weather changes from day to day Some days are warm and some are cold Climate is the usual weather for a place For example some places are warm in summer but cold in winter Earth's climate is the climate of the whole planet It's what you get when you add up all the different climates around the world Rain is a type of weather Some places have a rainy climate while others have rain only occasionally
5 This illustration shows the ice age a time period in the past when Earth was much colder than it is in modern times Just as weather can change so can climate Weather can change quickly but it takes a long time for climate to change Climate change takes hundreds or thousands of years Through Earth's history the climate has changed many times At times in the past Earth was warmer At other times it was colder These warm and cold periods lasted for thousands or even millions of years
6 Earth's Fever Scientists tell us Earth's climate is changing again This time the climate is growing warmer The planet's temperature has gone up a little more than 1°F 0 6°C over the past hundred years Scientists say Earth will keep growing warmer over the next hundred years The extra heat will cause rising seas flooding droughts and severe weather A warming climate can mean more extreme storms of all kinds even blizzards
7 Cutting down forests contributes to climate change Without trees to soak up carbon dioxide more of the gas builds up in the atmosphere In the past Earth's climate changed because of natural events Sometimes the sun would send out more or less energy Sometimes a volcano would erupt and that would change the climate But this time is different Human activity is changing the climate Riding in cars turning on lights and heating and cooling our homes all contribute to climate change These activities require the burning of fossil fuels such as coal natural gas and oil Burning these fuels has a big effect on the planet's climate
