Download Environmental Concerns

Environmental Concerns
Bio.2.2.1 Infer how human activities (including population growth,
pollution, global warming, burning of fossil fuels, habitat destruction
and introduction of nonnative species) may impact the environment
Bio.2.2.2 Explain how the use, protection and conservation of natural
resources by humans impact the environment from one generation to
the next.
Atmosphere
• Important parts of the
atmosphere are greenhouse
gases, which trap heat on
Earth, and the ozone layer,
which shields Earth from UV
• The atmosphere’s ability to
trap heat is called the
greenhouse effect.
The rest of the Bioshpere
• The biosphere includes all parts of
Earth where life exists.
• A very small portion of the hydrosphere
is fresh water, and much of this fresh
water is not easily usable.
• The geosphere exchanges materials
with the atmosphere, hydrosphere, and
biosphere.
Biodiversity
• Biodiversity refers to the variety of life found in an
area.
• Biodiversity can be measured in different ways,
including by species richness, species evenness, and
genetic diversity.
• Species richness – the number of different species
• Species evenness – how close in numbers each species is
• Genetic diversity – total number of genetic characteristics
in the genetic makeup of a species
Pollution
• Ozone Thinning
• Industrial chemicals called
chlorofluorocarbons (CFCs) act as
catalysts in chemical reactions that
break down O3 molecules in the
ozone layer.
• Most countries have banned
CFCs, and the ozone layer seems
to be recovering.
Pollution
• Global Warming
• The correlation of increasing
atmospheric CO2 and rising global
temperature suggests a cause-andeffect relationship.
• Considering several types of
evidence, many scientists have
concluded that increased CO2
levels have caused warmer surface
temperatures on Earth.
Pollution
• Acid Precipitation
• Air pollutants such as sulfur
cause acid precipitation, which
harms or kills many organisms.
Pollution
• The release of toxic
chemicals, such as DDT,
into the biosphere can
impact ecosystems in
many ways, especially
when chemicals undergo
biological magnification.
Extinction
• Human impacts on the environment are causing an
increasing number of extinctions.
• Important causes of extinctions are habitat destruction,
the transfer of invasive species to new habitats, harvesting,
and hunting.
• This loss of species has both known and unknown effects
on ecosystems.
• Species such as the sea otter that affect many other species in
a community are called keystone species.
Conservation and Restoration Biology
• Conservation biologists are
concerned with identifying and
maintaining ecosystems, while
restoration biologists are usually
involved with repairing badly
damaged ecosystems.
• Species and Habitats
• A bioindicator is a species that is
especially sensitive to ecological
change.
• Ex. Lichen
Conservation and Restoration Biology
• Case Study: Saving the Whooping
Crane
• Populations of many migratory birds,
such as the whooping crane, are in
decline because of human activities.
• However, some populations are
recovering as a result of legal
protection, breeding programs,
habitat restoration, and international
partnerships.
Protecting Ecosystems
• Biodiversity Hotspots
• International and cooperative
efforts to preserve habitat and
prevent extinctions include
identifying biodiversity hotspots,
making debt-for-nature swaps
(preserve your country’s
environment and this country will
forgive some or all of your debt) ,
and promoting ecotourism.
Conservation Case Study: The Everglades
• The Everglades restoration project is the most
ambitious ecosystem-wide restoration project
attempted in the United States.
• Authorized by congress in 2000 to “restore, preserve, and
protect south Florida ecosystem while providing for other
water-related needs of the region, including water supply
and flood protection.”