biodiversity

Just as nations have different levels of population, industrial and agricultural production, income and education, so they have varied environmental impacts. Such impacts aren’t stable over time: Countries’ use of resources and generation of wastes often rises as production grows, then may fall as cleaner technologies and better environmental practices come into use. While this trend has been theorized, empirical evidence has been mixed.

When humans hunt and fish, they tend to favor animals that provide significant resources. In the oceans, whales, sharks and other large vertebrates have been targeted for centuries, and while the international ban on whaling has helped some species recover in select areas, many populations have fallen to a fraction of their natural levels.

According to the Environmental Protection Agency, urbanized land in the United States increased by 48% from 1982 to 2003 and now covers more than 100 million acres. This expansion of cities and suburbs has had significant impacts on wildlife through habitat loss, pollution and the introduction of nonnative species.

Because wolves were considered to be the primary threat to the dwindling woodland caribou population in the petroleum-rich Alberta oil sands region, the Canadian government implemented an aggressive wolf eradication policy in 2010. However, human encroachment has also been exerting pressure on the caribou population, as part of expanding natural resources extraction efforts in that region.

Since the Endangered Species Preservation Act was signed into law in 1966, local and global endangered species lists have emerged as useful tools for protecting threatened animal and plant populations.  Prioritizing resources is essential, however, and local situations don’t always reflect global realities — a species could be threatened in one area but plentiful overall, or locally plentiful but in danger worldwide.