Past Climate Change

Question 1

When did the Quaternary period start?

Answer 1

2.6 million years ago.

Question 2

What period started 2.6 million years ago?

Answer 2

The Quaternary period started 2.6 million years ago.

Question 3

What is a glacial period?

Answer 3

A period with cooler temperatures and ice advances, lasting thousands of years (about 100,000).

Question 4

What is a period with cooler temperatures and ice advances?

Answer 4

A glacial period.

Question 5

What is an interglacial period?

Answer 5

A period with warmer temperatures and ice retreats, lasting thousands of years (10,000 years on average).

Question 6

What is a period with warmer temperatures and ice retreats, lasting thousands of years (10,000 years on average)?

Answer 6

An interglacial period.

Question 7

Give an example of a glacial period.

Answer 7

An example of a glacial period is the Little Ice Age.

Question 8

Give an example of an interglacial period.

Answer 8

An example of an interglacial period is the Medieval Warm Period.

Question 9

What are all the pieces of evidence for climate change?

Answer 9

Ice and Sediment Cores, tree rings and pollen analysis are all pieces of evidence of climate change.

Question 10

How are ice cores obtained?

Answer 10

Scientists drill into glaciers and pulling out cylindrical ice cores to analyse.

Question 11

How can scientists tell temperature from ice cores?

Answer 11

If there are low levels of CO2 in the ice cores then there was a low temperature, whereas if there are high levels then, most likely the temperature was higher.

Question 12

How far back can ice cores tell the temperature?

Answer 12

Ice cores can give evidence from at least 400,000 years.

Question 13

How can scientists tell climatic conditions with sediment cores?

Answer 13

Scientists use organisms found in sediment cores, which are more accurate and hold records going back 5 million years.

Question 14

How long ago can sediment cores hold information about the climate?

Answer 14

5 million years.

Question 15

Ice cores can only collect data when?

Answer 15

Ice cores can only collect data during periods of snowfall. No snowfall means no data.

Question 16

How often is a tree ring grown?

Answer 16

Tree rings are grown once per year if the tree is alive.

Question 17

What do thicker tree rings indicate?

Answer 17

Thicker tree rings indicate warmer, wetter conditions.

Question 18

What do thinner tree rings indicate?

Answer 18

Thinner tree rings indicate cooler, drier conditions.

Question 19

What do tree rings measure?

Answer 19

Tree rings measure multiple aspects of climate - temperature and precipitation.

Question 20

How long back can tree rings collect data?

Answer 20

Tree rings can measure data from up to 14,000 years ago.

Question 21

What can make tree rings inaccurate?

Answer 21

Non-climate factors such as soil, fire and disease affects tree rings, making the size possibly less valid.

Question 22

What does pollen analysis involve?

Answer 22

Pollen analysis involves examining preserved pollen from plants that has become trapped in sediment.

Question 23

What are scientists able to do with this pollen trapped in sediment?

Answer 23

Scientists are able to identify and date the pollen to show which species were living at a given time, and as they know what conditions the plants that are living now they are able to deduce the climatic conditions of the time.

Question 24

What is a disadvantage of weather stations?

Answer 24

They are not evenly distributed across the world, meaning that climate change is difficult to measure.

Question 25

Since when were global temperatures accurately measured?

Answer 25

Global temperatures have been measured accurately since the 1850’s.

Question 26

What are the natural causes of climate change?

Answer 26

The natural causes of climate change are sun spots, Milankovitch cycles (eccentricity) and volcanic eruptions.

Question 27

What is the shape of Earth’s orbit?

Answer 27

The shape of Earth’s orbit is eccentric.

Question 28

What causes Earth’s orbit to be eccentric?

Answer 28

The gravitational pull from gas giants Jupiter and Saturn causes the Earth’s orbit to be pulled from circular to slightly elliptical.

Question 29

What is obliquity and what does it cause (short answer)?

Answer 29

Obliquity is the Earth’s tilt, and is why the Earth has seasons.

Question 30

What has obliquity varied between?

Answer 30

The Earth’s obliquity has varied between 22.1 and 24.5 degrees with respect to Earth’s orbital plane.

Question 31

How long is the cycle of obliquity?

Answer 31

The cycle of obliquity lasts about 41,000 years.

Question 32

What is precession, and what is it for the Earth?

Answer 32

Precession is the Earth’s wobble, and it wobbles like a slightly off centre spinning toy top.

Question 33

What is the cycle of axial precession?

Answer 33

The cycle of axial precession runs about 26,000 years.

Question 34

When the Earth’s orbit is at its most elliptic, what percent more solar radiation reaches the planet?

Answer 34

When Earth’s orbit is at its most elliptic, about 23 percent more incoming solar radiation reaches Earth at our planet’s closest approach to the Sun each year than does at its farthest departure from the Sun.

Question 35

What do volcanic eruptions release?

Answer 35

Sulfuric acid and carbon dioxide.

Question 36

What does more sulfur and carbon dioxide mean for the atmosphere?

Answer 36

The atmosphere is able to deflect more solar insoation from reaching the Earth, pushing us into a little ice age as it cools temperatures.

Question 37

Every 11 years, the output of what increase?

Answer 37

Every 11 years, the output of sun spots increases.

Question 38

What does more sunspots result in?

Answer 38

More sunspots means there will be more sulfur, and more flares.

Question 39

What does more sulfur and more flares result in?

Answer 39

More sulfur and flares results in increased light and heat towards Earth.

Question 40

What does increased light and heat towards Earth result in?

Answer 40

Increased light and heat towards Earth results in increased insolation.