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