🚀 go-pugleaf

Hi,

With this mail I want to encourage a discussion on the term 'threshold' in
relation to the environment and to climate change.

I am myself doing research on climate change and its thresholds for
migration of people in Africa. By going along my research, I found out that
the term 'threshold' has been used, nearly over-used in many contexts
without that any author gave clear definitions on the term. Therefore, I
thought I could use this lack of definition to write in my university
course (I am student at the University of Oslo, Norway) a paper on
'thresholds - how to be defined from natural and social science point of
view'.



My questions I am addressing are the followings:

1)  How can a 'threshold' be defined, in the view of a natural scientist
and social scientist?

definitions so far a very scarce: I looked into Britannica on-line,
Webster's dictionary, etc where I found in brief just such definitions:

it is -
- a kind of limit that - when exceeded - causes a reaction
- the smallest maginitue at which something can happen
- an end
- point of entering/beginning

2) Is it right, that a social scientist defines 'threshold' more in
relative terms and a natural/environmental scientist rather in absolute terms?

example: A threshold for becoming angry after verbal atacks varies among
individual people. A threshold for clorine per liter water still allowing
fishes to survive is xxx mg.

3) A threshold for many environmental issues is variable, depending on a
systems adaptive capacity and vulnerability.

If a certain negative influence - e.g climate change - occurres only slowly
- a certain bird specie still can migrate and thus, it's threshold for
extinction is higher than under a sudden climate change.

The more vulnerable a society (little economic resources and technological
performance,high illiteracy,...) the lower the threshold for migration
under climate change.



I would appreciate it very much if I could get comments on my brief
statements. It would be helpful and interesting to start a discussion on
the topic.



Elisabeth Meze
CICERO Center for International Climate and Environmental Research - Oslo
University of Oslo
P.B 1129 Blindern
0317 Oslo
Norway