However, the vast majority of illegal immigrants come to developed countries for the more menial job opportunities. They rarely are able to substantially or quickly raise their socio-economic condition.
We know that environmental impacts generally vary according to standard of living and economic status. That is, the higher the standard of living, the greater the consumption of natural resources (usually externalized to poorer areas and developing nations), as well as generated pollution. On the other hand, people in developing nations usually degrade and pollute their environments locally, and don't have the same high level of technology to mitigate these effects.
What is the relevance of this to our discussion on the environmental impact of immigrants vs that of native-born citizens?