evidence for climate change

Question 1

What is climate change?

Answer 1

Any significant change in the Earth’s climate over a long period. The climate constantly changes, it always has, and it always will.

Question 2

What’s the Quaternary period? How long ago did it start?

Answer 2

The most recent geological time period, spanning from about 2.6 million years ago to the present day.

Question 3

How was the period before the Quaternary period like?

Answer 3

The Earth’s climate was warmer and quite stable. Things then changed a lot.

Question 4

What was the global temperature like during the Quaternary?

Answer 4

Global temperature has shifted from cold glacial periods that last for around 100,000 years, and warmer inter glacial periods that last for 10,000 years.

Question 5

How long ago did the last glacial period end? What has been happening since then?

Answer 5

The last glacial period ended around 15,000 years ago. Since then, the climate has been warming.

Question 6

What is global warming?

Answer 6

The term used to describe the sharp rise in global temperatures over the last century. It’s a type of climate change.

Question 7

What are the four main sources we use as evidence for climate change? List them in order of how reliable they are.

Answer 7

Ice cores, Sea ice positions, temperature data, diaries and paintings

Question 8

What are ice sheets made up of?

Answer 8

Ice sheets are made up of layers of ice- one layer is formed a year

Question 9

What do scientists do to get long ice cores?

Answer 9

Scientists drill into ice sheets to get long cores of ice.

Question 10

Using ice cores, how can we tell the temperature from over the years?

Answer 10

By analysing the gas trapped into each layer of ice. They can tell us what temperature it was each year.

Question 11

Can we trust data collected from ice cores?

Answer 11

Data collected from ice cores and very reliable and detailed.

Question 12

How, when and where do sea ice form and then melt?

Answer 12

Sea ice forms around the poles in winter ocean temperatures fall below -1.8 degrees C. They melt during the summer when it’s warmer.

Question 13

How can scientists tell how ocean temperatures are changing from the sea ice?

Answer 13

By observing the maximum and minimum extent of sea ice each year, scientists can tell how the temperature is changing.

Question 14

Can we trust the data of sea ice positions?

Answer 14

The data is very reliable, but accurate records don’t go far back.

Question 15

How are global temperatures measures accurately since the 1850s?

Answer 15

Since the 1850s, global temperatures have been measured accurately using thermometers.

Question 16

Can we trust the data we get from measuring global temperatures using a thermometer?

Answer 16

They give a reliable but short-term record of temperature change. Also, weather stations are not evenly distributed across the world- data from some areas is patchy.

Question 17

How can historical diaries show what climate was like in the past?

Answer 17

By giving the number of days of rain or snow and the dates of harvest. An early harvest suggests warm weather.

Question 18

How can old paintings show how the climate was like in the past?

Answer 18

Paintings of fairs and markets on frozen rivers show that winters in Europe were regularly much colder 500 years ago than they are now.

Question 19

Can we trust diaries and paintings in telling us how climate has changed over time?

Answer 19

Diaries and paintings aren’t very reliable, as they just give one person’s viewpoint.