Unit 1: Is our climate really changing? Flashcards
Describe the trend of … (chart)
(list out the aspects to describe)
1) In general, the global average temp has been increasing/decreasing
2) FIGURES (it increased from … to … in (year))
3) phenomenon -> name
Global warming vs Climate changes
Global warming:
1. GRADUAL increase of global average temperature due to intensified greenhouse effect in the atmosphere
Climate changes:
1. LARGE-SCALE SIGNIFICANT long term changes in pattern of WEATHER
2. from global to local scale
3. changes occur over decades or longer
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include:
1) Average temperature + precipitation
2) Seasonal / geographical variation of temp + precipitation
What evidence is there to prove that our climate is really changing?
1) Increasing global temperature, ocean temperature, global mean sea level
2) Shrinking + reclining Arctic sea ice
3) Shrinking + retreating glaciers
4) Increase in extreme weather events
5) changes in global precipitation patterns
6) lengthening of growing season of crops
7) poleward migration (warmer climate fish, tree species)
8) earlier breeding + flowering + migration patterns of plants and insects in the NORTHERN HEMISPHERE
warmer earth leads to..
1) melting of glacier ice on land (-> melts and flows into oceans -> sea level rise)
2) thermal expansion of seawater
SEA ICE IS NOT GLACIERS
proof of increase in extreme weather events
1) heat waves have become common (etc, eu)
2) more intense periods of rainfall
-> high risk of flooding (etc. hawaii)
3) stronger tropical cyclones
4) more frequent droughts (etc. USA, the Sabel)
proof of changes in global precipitation pattern
1) generally increased over the mid latitude land area of the northern hemisphere (etc. northern + central EU.
, central + eastern north America
2) some places have become drier (etc. East Asia, the Sahel region)
3) global precipitation pattern changes
- more intense rainfall
- shorter duration of rainfall
- precipitation often falls as rain than snow in higher latitude regions
How are some hurricane caused by global warming?
warmer ocean temperature -> moisture increases -> rising sea levels ->’easier to form
Why do some people believe that global warming is fiction?
1) There have been numerous changes in global climate throughout the Earth’s history
2) Ice ages have occurred several times during the past millions of years (last ice age ended about 10 000 years ago)
3) Approximately every 100 000 years the Earth’s climate warms up temporarily. (inter-glacial periods)
4) Since the end of the last ice age, the Earth’s temperature has raised approximately 10°C and sea levels have raised a total of 100 metres
5) It is normal for average temp to fluctuate
6) lack of precise and accurate dimatic data in the old days to prove whether the recent rise in air temperatures is not normal
8) The long-term fluctnation may be caused by some natural factors.
Why do some people believe that global warming is fact?
Pattern of temperature increase coincides with the rapidly surging CO2 concentration on the atmosphere since 1950s
What is the greenhouse effect?
- a natural phenomenon
- refers to part of the long-wave radiation being absorbed by greenhouse gases in the atmosphere and re-radiated back to the Earth’s surface
-> keeps lower atmosphere warm
cause-and-effect relationship: intensified greenhouse effect -> global warming
solar radiation comes to the earth in form of short wave radiation
some of the radiation from the sun is:
1. reflected by earths surface + atmosphere
2. absorbed by earths surface + atmosphere
-> earth surface heats up
What are greenhouse gases?
Greenhouse gases are gases that absorb radiation
1) CO2
2) CH4
3) SF6
4) H2O
5) CFCs
6) HFCs
7) PFCs
8) ozone
9) water vapour
-> most abundant, absorbs heat
natural sources of carbon dioxide
1) respiration
2) wildfires
3) volcanic eruptions
4) decay of organic matter
