1) Once in the air, DMS is converted to sulphate aerosol particles. Which statement about sulphate aerosols is not correct?
a) sulphate aerosols breakdown CO2 and reduce global warming
b) sulphate aerosols cool the Earth by reflecting sunlight back into space
c) sulphate aerosols are formed from sulphuric acid and this affects how acid our air is
d) sulphate aerosols help to form clouds and clouds affect our climate
2) Halogen containing gases are emitted into the air from seawater. These halocarbons reduce human health problems and decrease global warming by...
a) trapping radioactivity
b) lowering the amount of water vapor in the air
c) trapping ultraviolet rays from the sun
d) destroying tropospheric ozone
3) Which of the following greenhouse gases is not emitted by seawater?
a) CFC-11
b) methane (CH4)
c) water vapour (H2O)
d) nitrous oxide (N2O)
2. Phytoplankton and climate
Put these statements in the order in which they occur:
DMSP is released into seawater
phytoplankton produce DMSP
DMS is converted into sulphate aerosols in the air
phytoplankton die or are eaten
some DMS escapes from the sea into the air
sulphate aerosols cool the Earth by reflecting sunlight back into space or by forming clouds
DMSP breaks down into DMS
3. Halocarbons and human health
Describe at least two ways (direct or indirect) in which halocarbons from the ocean affect human health.
Authors: Ellen K. Henriksen and Camilla Schreiner - University of Oslo - Norway. Scientific reviewer: Lucinda Spokes - Environmental Sciences, University of East Anglia, Norwich - U.K. Quiz programmer: Julia Heres - University of Nürnberg - Germany. Last update: 2004-03-27.
> ENC Master > Climate Encyclopaedia > Oceans > basics > 3. Gases from phytoplankton > * Worksheet 2
