hazardous earth - climate change

Question 1

define ‘glacials’

Answer 1

a time with very low global temperatures - some glacial periods came with ice ages which lasted several hundred years

Question 2

define ‘interglacials’

Answer 2

the warm periods in-between the glacials

Question 3

explain three ways in which we can tell what past climate was like

Answer 3

• tree rings - warmer and wetter years lead to larger rings/ more growth
• ice cores - bubbles of carbon dioxide are trapped in the ice layers. scientists can reconstruct past temps by measuring the amount of carbon dioxide
• historical sources - old photos, paintings, diaries and newspapers can be evidence of climate change but aren’t always accurate

Question 4

what is the eruption theory and how does it affect climate?

Answer 4

volcanic eruptions produce ash and gas which acts as a blanket, reflecting sunlight back into space so cools the planet

Question 5

what is the asteroid collision theory and how does it affect climate?

Answer 5

large asteroids blast ash and dust into the atmosphere, which blocks incoming sunlight and cools the climate. effects can last 5-6 years

Question 6

what is the sunspot theory and how does it affect the climate?

Answer 6

the number of spots on the sun changes, the more spots there are, the more active the sun is (hotter). climate change over a few hundred years may be explained by sunspots

Question 7

what is the orbital theory and how does it affect the climate?

Answer 7

the earth’s orbit, tilt and wobble affect the amount of sunlight the earth receives. these changes are called the milankovitch cycles

Question 8

what is the enhanced greenhouse effect?

Answer 8

it is responsible for global warming as there are more greenhouse gases in the atmosphere. these extra gases have been produced by humans

Question 9

what percent of the world’s glaciers are shrinking?

Answer 9

over 90%

Question 10

what is thermal expansion

Answer 10

when sea water warms up, it expands