The effects of global warming have caused humans to open their eyes to the vulnerability of ecosystems and the inhabitants who live in them. The cause of global warming can be attributed to greenhouse gases (Robinson et al 2009). Greenhouse gases in the atmosphere allow the Earth to stay warm by providing blanket-like coverage. However, since the 19th century, humans have caused an increase in the production of greenhouse gases in the atmosphere due to the growing oil and coal economy (Robinson et al 2009). The increase in greenhouse gases resulting from the use of fossil fuels is like throwing a second blanket over the Earth. Consequently, the increase in greenhouse gases causes an increase in temperature (Maxwell 1992). From 1840 to the mid-20th century the Arctic warmed to its highest temperatures in four centuries (Overpeck et al 1997). The average air temperature in the Arctic has increased by 5 degrees Celsius over the last 100 years (wwf). Another cause that influences global warming is deforestation. Trees act like a sponge that absorbs carbon dioxide from the air, yet trees are continually cut down to build cities. Cutting down trees essentially increases carbon dioxide levels in the air. As a result, over the last twenty years there has been a 20% increase in CO2 levels in the atmosphere (Arctic ecosystems in a). In nature the climate system will fluctuate periodically, but the critical point is that the baseline will continually be raised as the years pass. Polar bears (Ursus maritimus) live in the circumpolar Arctic on frozen ice, along or near coasts, and on islands. Today, scientists believe that there are approximately 22,000 polar bears in the world (Derocher 2004). Most of... half the paper... is fractured and labile, likely to move more in response to winds and currents, so polar bears will need to walk or swim more and therefore use a greater amount of energy to maintain contact with the remaining preferred habitats. Rising temperatures in the Arctic, toxic pollution, the introduction of oil and excessive hunting have led to polar bears being placed on the endangered species list. If these factors are not drastically reduced the species will become extinct. The effects of climate change are not constant but can change drastically at any moment. Therefore we humans cannot adequately measure and predict the effects of climate change 100%. Behavioral plasticity has been used to describe the adaptation of polar bears to climate change, however with the increasing effects of greenhouse gases bears will be unable to adapt leading to extinction.