The starting point for the analysis of the impact of human factors on the environment is the work by Burke and collaborators that shows that almost all variation in agricultural land use in the Great Plains is explained by variation in environmental variation. Not much room is left for human intervention. Different ethnic groups continue to crop differently, all other things equal. In an interesting note, Gutmann and Cunfer point out that in the absence of plowing, high temperatures could have been part of a weather complex that produced grass fires, which would have also cleared the soil and made it vulnerable to become blowing dust. In addition to transforming the environment, the human population is shaped by the environment and by environmental change.
Migration is a key component of the impact of environmental change on population.
The environment has another impact on migration, in the opposite direction. Beginning in the 1960s, high elevation counties in the Great Plains experienced significant positive net in-migration. This is a result of lifestyle and recreational migration, with population growth near mountains and recreational boating. The farm family surveys are being analyzed for a number of purposes. One of the first research undertakings based on the surveys is an exploration of household income packaging.