P2c: Global warming

Question 1

What can pass through the Earth’s atmosphere and what cannot?(2)

Answer 1

Electromagnetic radiation at most wavelengths can pass through

Electromagnetic radiation at certain wavelengths, especially infrared radiation, cannot pass through as they are absorbed by gasses in the atmosphere

Question 2

Greenhouse gases (3) + % of atmosphere + natural sources + man-made sources

Answer 2

water vapour; 0.4; water cycle; none of significance

carbon dioxide; 0.039; volcanic eruptions, waste product of respiration from all living things; extraction and burning of fossil fuels, transport, deforestation

methane; 0.0002; animal waste; intensive farming, extraction and burning of fossil fuels

Question 3

Explain the greenhouse effect (4)

Answer 3

short wavelength EM radiation from the Sun pass through the atmosphere and is absorbed by and heats the Earth

the Earth radiates heat as longer wavelength infrared radiation

greenhouse gases (CO2, methane, water vapour) absorb some infrared radiation, warming the atmosphere

gases then re-radiate heat in all directions, including back towards Earth

Question 4

ow do both human activity and natural phenomena have effects on weather patterns? (2)

Answer 4

soot/greenhouse gases in the atmosphere from factories, reflecting radiation from the city back to Earth, +temperature/global warming

dust/greenhouse gases in the atmosphere from volcanic ash and gases reflecting radiation from the Sun back into
space causing cooling; ice age

Question 5

Scientific evidence which refutes the idea of man-made global warming

Answer 5

part of a regular cycle of warming and cooling; some historical evidence - planet has been both cooler and warmer in the past

Question 6

Scientific evidence which supports the idea of man-made global warming

Answer 6

as more and more carbon dioxide is released (via +combustion, +deforestation), the process of global warming appears to be accelerating

Question 7

Describe the debate on climate change (2)

Answer 7

agreement about the greenhouse effect warming planet at an increasing rate, leading to climate change

disagreement about whether human activity is affecting global warming

Question 8

Why should scientists working on global warming allow other scientists to use their data?(2)

Answer 8

scientists use evidence to support their ideas

-the more evidence, the more accurate the conclusions - important that scientists share their data

Question 9

Difficulties of measuring global warming (2)

Answer 9

climate change takes place over hundreds of years

there are climate variations every year