entropy > energy flows in an ecosystem energy sources for organisms
TRANSCRIPT
entropy >
Energy flows in an ecosystem
Energy Sourcesfor Organisms
Figure 9.3
IN OUT OUT
GhE
The Great Weather Engine
7
2
collects
3
1
4Cycle drives thehydrologic cycleby loading water,moving it andunloading it.Chapter 10
Moving aircreates the pressure differences
Figure 9.6
The Great Weather Engine
5collects
10
Ecological Economics
neoclassical economics ecological economicsnatural resources
obtain... use... discard obtain... use... reuse... recycle natural capital
regarded as plentiful, cheap seen as valuable recycling of materials
takes place in ecosystems that are regeneration part of the valued as resources & waste dumps economy
fossil energy built food forest consumed environment land products
energy consumed farm land forest land land land
FOOTPRINT takes into account
the land use for supporting
humans shown in the diagram at
the left.
ECOLOGICAL FOOTPRINT- amount of land needed to support a given activity… for example, life of a city
126 billion acres of earth surface
31 billion acres of bio-productive land
6 billion people on earth
5.2 acres of bio-capacity… a 5.2 acre footprint
7 acres per person is the average footprint at present
1 acre per person is the footprint allowed it we allot 80 % of the earth for non-human ecosystems
0 10 20 50 100 150 2000
1000
2000
500
3000
4000
5000
6000P
opu
lati
on in
Mill
ion
s
Per Capita Energy Use Kcal/day
World load in 1986
World load in 1999At US per capita level
World load in 1800
World load in 1500
US load in 1986
Stress-effect of population and resource/energy use on Earth is the “Footprint”. Ecological economics will reduce per capita use of energy and natural resources Less load on the Earth
Recallthe thirdfactorthat isrelated toload onthe EarthCARE
fossil energy built food forestconsumption environment land products
graph areas
representthe size of
thisfootprint
Ecological Economics
Shrinking the Waste Stream• some approaches to waste reduction
– producing less waste the most basic and effective one • life-cycle assessment of products to reduce waste, toxics
• evaluate mining, harvesting, manufacturing, packaging processes