What % of the USA land surfaces has been altered by any kind of human development?
Also, if all roads & highways were placed together, what % of the USA would be paved or unpaved over? The destruction of US landscapes by road building is horrendous if not insane!
- AlexLv 78 years agoFavorite Answer
There are about 3 million miles of paved roads in the US. Assuming an average width of 70 feet (roughly a 4-lane highway), this would be about 40,000 square miles. The total area of the 48 contiguous states is 3.12 million square miles, so 1.2% is roads.
I would say almost 100% of it has been altered. Even national parks have a roads, buildings, and trails. According to the USDA in 2002, land use in the US (including Alaska) is as follows:
Grassland pasture: 26%
Parks and preserves: 13%
Urban areas: 3%
- 8 years ago
If you're really picky, it's 100%. The building of a factory in California creates pollution, which wind carries the pollution across other areas of the USA, possibly as far as the very north west. While a single factory would have limited consequences to the other side of somewhere as vast as the USA, when the effect is multiplied by several thousands, the effects are profound.
Also, consider that the great wilderness' of the world such as Northern Siberia and Antarctica still contain people affecting the area around them. As these contain population density's that aren't even close to the least dense areas of the US, you can begin to appreciate just how much impact humans have on US land.