10.3 2 Human influences on climate change Flashcards
climate change
global temperatures are increasing
levels of carbon dioxide and other green house gases are increasing in the atmosphere
greenhouse gases
reduce heat loss from the surface of the earth
without life would not be possible-maintain surface temperature suitable for life
examples of greenhouse gases
carbon dioxide
methane
water vapour
greenhouse effect
when radiation of sun reaches the earth some is reflected back into space by the atmosphere and the surface
some is absorbed by the atmosphere
infrared has a relatively short wavelength is absorbed by the surface and then radiated at a longer wavelength
some of this radiation is abdorbed and re-radiated back to the earth surface by green house gas molecules in the atmosphere
evidence for global temperature increases
UK met office has temp records back to late 1800s but even more from diaries
frozen isotopes
in antartic and greenland
analyse air trapped in different layers of ice
co2 levels can be measured
oxygen isotopes in melted ice reflect air temperature
carbon dating
tree-ring growth
evidence for increasing levels of carbon dioxide
Mauna Loa curve hourly average co2 level since 1958
incrasing
ice core data
ph of oceans
The role of methane
CH4 has greater warming effect in the atmosphere
decay of organic material cattle rice paddy fields
remember
correlation vs causation
since industrial revolution
burnt increasing quantities of fossil fuels
what is the greenhouse effect
the process
gases in earths atmosphere absorb and re-radiate radiation from the sun which has been reflected from earth’s surface
Dendrochronology
dating of past events using tree-ring growth
Anthropogenic
produced by people
