Compare the effects humans have on the south american continent to those that effect the african continent. provide two examples of how these effects are the same or different.

One of the main problems that the world faces nowadays is that of environmental degradation. Environmental degradation occurs when the natural ecosystems of an area deteriorate due to the depletion of resources such as air, water and soil. It can also be affected by habitat destruction, extinction of wildlife and pollution. Although this undesirable process takes place all over the world, Africa and South America are particularly at risk for several reasons.

One reason that both areas share is overpopulation. Population growth is particularly fast in Sub-Saharan Africa. For example, from 1950 to 2010, the population of Sub-Saharan Africa grew over three and a half times, from about 186 million to 856 million. It is the fastest growing rate in the world. Latin America has also struggled with unplanned growth for decades, with many cities growing in an unplanned way and without equal access to resources. This has led to the depletion of resources and the destruction of ecosystems.

Another example of practices that both regions share is that of unplanned deforestation for agriculture. This leads to reduced wildlife, loss of ecosystems, and depletion of nutrients in soil. It can also increase the effects of global warming.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)

answer; knowledge,reason,and judgement;