http://www.ck12.org Chapter 5. Understanding Biodiversity: Global Climate Change
5.1 Global Climate Change and Biodiversity
Understanding Biodiversitydoes not attempt to provide a complete review of climate change. For additional
information about climate change, see theCommunities and Populationschapter in the CK-12 Biology FlexBook®
textbook at http://www.ck12.org/flexbook/book/2537 and theEcology and Human Actionschapter in the CK-12
Biology I - Honors FlexBook® textbook at http://www.ck12.org/flexbook/book/829.
Does global climate have an effect on biodiversity? How could it not?
A major problem caused by increased air pollution is global climate change. Global climate change refers to a
worldwide significant and lasting change in the distribution of weather patterns over periods ranging from decades
to millions of years. This change may be a change in average weather conditions or the distribution of events that
influence the average weather conditions.
What causes this change? It is probable that gases such as carbon dioxide from the burning of fossil fuels increase
the natural greenhouse effect. This raises the temperature of Earth’s surface. This has numerous consequences. Does
this climate change affect biodiversity? Of course it does. And probably in a negative fashion.
What Is the Greenhouse Effect?
Thegreenhouse effectis a natural feature of Earth’s atmosphere. It occurs when gases in the atmosphere radiate the
sun’s heat back down to Earth’s surface (see theFigure5.1). Otherwise, the heat would escape into space. Without
the greenhouse effect, Earth’s surface temperature would be far cooler than it is. In fact, it would be too cold to
support life as we know it.
FIGURE 5.1
The Greenhouse Effect. Without green-
house gases, most of the sun’s energy
would be radiated from Earth’s surface
back out to space.