Climate Topic 2: Climate Change

Climate change refers to

• global warming

• global cooling

Which of the following best describes the temperature pattern shown in the graph?

• Temperature is mostly cold, with a few periods of warm

• Temperature fluctuates between warm and cold in fairly regular cycles

• Temperature is mostly warm, with a few periods of cold

• The warm and cold periods last approximately in a cycle of every 100,000 years

How does scientists determine the past climates of the Earth?

• By consulting ancient texts and scriptures

• By analyzing the color of the sky
• By analysing sediments from the seafloor and oxygen

• By observing the behavior of modern animals

• Lower concentrations of ​ (a)   (i.e. oxygen-18 isotope) in the ocean tells us that the earth's climate is ​ (b)  

• warmer.
• light oxygen
• heavy oxygen
• cooler.

• Higher concentrations of ​ (a)   (i.e. oxygen-18 isotope) in the ocean tells us that the earth's climate is ​ (b)  

• warmer.
• light oxygen
• heavy oxygen
• cooler.

Organise the natural causes of climate variability below over varying timescales.

Groups:

(a) Long-term natural causes

,

(b) Short-term natural causes

• • Large-scale volcanic eruptions.

• 1. Changes in Earth's angle of tilt.

  
  

• • Changes in Earth’s orbit.

• • Occurrence of sunspots.

When the Earth’s orbit is the most ​ (a)   , the Earth receives ​ (b)   solar radiation at its closest approach to the Sun than it does at its furthest departure from the Sun.​

• more
• less
• elliptic

When the Earth's angle of tilt increases, seasons become more extreme.

• True

• False

The Earth’s orbit stretches from circular to an elliptical shape and back again, in a cycle that spans around

• 40,000 years.

• 50,000 years

• 100,000 years.

• 140,000 years

The Earth’s angle of tilt varies back and forth between 21.5° and 24.5°, in a cycle that spans around

• 41,000 years

• 50,000 years

• 100,000 years

• 150,000 years