You will be able to: Discuss human causes of climate change Explain the greenhouse effect Describe some of the implications of climate change.
16.1 How Do We Know That Our Climate Is Changing?
As we learned in Chapter 15, climate is the average weather across a large region measured over a period of time (30 years). Climate change means there has been a large change in the climate records of temperature, rainfall, wind speeds, etc., lasting decades or longer.
The earth’s climate has changed many times during its history. However, this current period is different, as there is evidence that human activity is speeding up natural climate change. In this chapter, we will look at the evidence that shows our climate is changing.
Temperature pre-1900
You will remember from Chapter 13 that temperature is measured using a thermometer . However, humans began to use thermometers to record temperature data only in the last 140 years. This means that there are no reliable weather records before the 1880s detailing the earth’s weather patterns, such as its temperature.