Consider an example--restoring the ecosystem at the Savannah River Plant

• government facility no longer needed to make bomb material
• new task--clean up the mess
• restore the ecosystem
• but even the natural areas have been changed by wild pigs and invasive species
• what was there before you built the reactors was exhausted farmland in bad shape
  

If we have messed up the environment and want to restore it to its original state, what is that original state?

• before there were any human beings there?
  
• when the Indians lived there?
• what was it like in 1492?
• what was it like when the Europeans started farming there?
• before settlers really changed things a lot?

Watch out for "common sense" assumptions that may be wrong, such as:

• there is a balance of nature and all we have to do is restore that
• the native Americans lived in harmony with the environment and didn't mess it up

The natural state of the natural world isn't balance:

• the natural state of some piece of land is something that changes over time as the environment changes
• do ecosystems have a natural equilibrium?
• the old idea was: "Except for a catastrophic event such as a widespread fire, for example, a forest will maintain itself and its inhabitants over a long period of time. If there is a catastrophic event, the ecosystem will reestablish itself through succession over a period of time, and eventually return to a stable populations of plants and animals." (originally from http://members.bellatlantic.net/%7Ebjmcg/Story4_vietnam_rats_deer.html)
  
• is this true? Not most of the time, according to scientists.  Are those catastrophic events not a part of nature?
• even setting aside catastrophic events, the pattern of an ecosystem is always shifting
• since the balance of nature is a myth, it is hard to figure out what ecosystem to restore
  

Human beings have affected the environment long before the 20th century

• even Native Americans modified the environment in fundamental ways (see below)
• human beings have changed the environment in a lot of different ways--do we count some and not others?
• what if we ask what was the environment like before there were people there
  

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Continental drift


200 million years ago all the continents had combined to form Pangaea
when they split North America stayed with Europe at first, so the plants and animals are less different
the plants and animals in Australia and New Zealand were more different because they were isolated for so long

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What happened when the first human beings arrived in some of the isolated areas?

• the ice ages lowered sea level and connected the continents that had been isolated
• human beings are able to quickly adapt to new areas--they don't have to wait for evolution
  
• humans arrived in Australia about 40,000 years ago, North America later
• some 10,000 years ago with the end of the ice ages isolation resumed
• they changed the environment
  
• some large mammals disappeared shortly thereafter (extinction of the megafauna), but probably not just from hunting
• human-started fires shaped the longleaf pine-wiregrass ecosystem of the sandhills and other environments

Consider the California Condor:

• it was part of the ecosystem with the megafauna
• has been in decline since the extinction of the megafauna
• it would probably be going extinct even if civilization hadn't come along
• should we save it?
• Europeans came into an environment that was not stable, it was changing
  

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The people of Australia and the Americas did not develop as advanced technology and farming as the people of Europe and Asia.  In particular they had far fewer kinds of domestic animals and were particularly short on animals to do work

Around 5000 years ago the people of Mesopotamia (Sumerians) had a full range of domesticated livestock and cities and writing appeared (Crosby lumps this with the invention of agriculture, but there are two steps, agriculture and irrigation)

Weeds, varmints (mice, rats, flies, etc.), and diseases  were problems Europeans struggled with on an ongoing basis

• Particularly in winter animals were often stabled in the ground floor of the family home
  
• Living in close proximity to livestock meant diseases went back and forth (eg. smallpox, influenza)
• People lived in crowded conditions and and raised tightly packed crops
• People coming from a crowded area have a disease advantage when they spread to other areas.

Even in Siberia, which had almost the same plants and animals as Europe, the indigenous people were laid low by diseases brought by Europeans