Study this graphic to see how the sources of primary pollutants produce

Study this graphic to see how the sources of primary

This preview shows page 16 - 18 out of 22 pages.

Image of page 16
States, before and after industrialization, 90 percent of indigenous forests have been destroyed since 1600.As noted earlier, the only regions that still feature indigenous boreal forests are mostly located in central Canada, Alaska, northern Russia, northern Japan, and northern Mongolia. The largestremaining indigenous tropical forests are found in the northwestern Amazon Basin and what is called the Guyana Shield of northern South America. That includes Guyana, Surinam, Venezuela, Colombia, and Ecuador. Other regions that support extensive tropical forests, as noted earlier, include Indonesia, Cambodia, Vietnam, Thailand, the southernmost "cone" of India, and the Congo Basin in the Democratic Republic of Congo.In general, global forests act as carbon dioxide sinks at the same time that they upload oxygen into the atmosphere. The capacity of that vital carbon sink is, obviously, reduced as trees are cleared. At the same time, trees and other kinds of vegetation emit carbon dioxide when they die, thus adding to global greenhouse gas and contributing heavily to global warming. According
Image of page 17
Image of page 18

You've reached the end of your free preview.

Want to read all 22 pages?

  • Fall '16

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture