Hydrology and Climate: Water's Unique Properties

Environment Definition

• Environment encompasses the physical factors surrounding humans, including land, water, atmosphere, climate, sound, odor, taste.
• It also includes biological factors, such as animals and plants, and the social factor of aesthetics.
• This definition is from the Environmental Quality Act, 1974.

Overview of Environment & Related Elements

• Environment comprises Physical, Chemical, Biological, Social, and Aesthetic factors.
• Physical: Water, Earth's atmosphere, sources & processes of pollutants.
• Chemical: Ecological concept, biogeochemical cycle, natural resources (rivers, wetlands).
• Biological: Ecological concept, biogeochemical cycle, natural resources (rivers, wetlands), biodiversity & conservation.
• Social: Health & environment, socio-political & environment, environmental education, environmental regulation & laws.
• Aesthetic: (no further detail provided).

Establishment of Department of Environment in Malaysia

• The Environmental Quality Act was approved on March 14, 1974 and enforced on April 15, 1975.
• A Division of Environment (BAS) was created on September 15, 1975, under the Ministry of Local Government and Environment.
• BAS was later transferred to the Ministry of Science, Technology and Environment in March 1976.
• BAS was upgraded to the Department of Environment (JAS) on September 1, 1983.
• JAS was moved to the Ministry of Natural Resources and Environment in April 2006.

Our Common Future (Brundtland Report)

• Published in 1987 by the United Nations World Commission on Environment and Development (WCED).
• Focused on multilateralism and interdependence of nations.
• Recaptured the spirit of the Stockholm Conference, which brought environmental concerns to the political agenda.
• Viewed environmental and development as a single issue.
• Resulted from a 900-day international effort involving governments, researchers, organizations, and the public..

The Brundtland Commission's Mandate

• Re-examine critical environment and development issues, and create realistic action proposals.
• Strengthen international cooperation.
• Raise awareness and commitment to action among individuals, organizations, and governments.
• Focused on population, food security, species loss, genetic resources, energy, industry, and human settlements.

UN Conference on the Human Environment (Stockholm, 1972)

• The UN Conference on the Human Environment was held in Stockholm between June 5-16, 1972.
• Sweden hosted the conference.
• The conference fostered international cooperation on environmental issues, including human rights, natural resources, and pollution.
• A set of recommendations, an action plan, and a resolution were adopted.

Water & Properties

• Water's unique physical and chemical properties make it essential for life.
• Water plays vital roles in the biosphere.
• Water exists in all three states (liquid, solid (ice), gas) on Earth's surface.
• Water's density is a maximum at 277K.
• Water expands when it freezes. This has ecological implications (rock weathering, lake stratification)
• Water has high surface tension. High cohesive forces allow many organisms to move on the water's surface. Capillary action in plants is facilitated by water's high surface tension.
• Water has a high heat capacity. This is a function of its hydrogen bonding. Organisms are able to maintain stable internal temperatures.
• Pure water is colorless, odorless, and transparent. This transparency allows the penetration of light through water bodies, enabling photosynthesis in aquatic plants.
• Thermal stratification in lakes: Epilimnion (top), Metalimnion/Thermocline (middle), and Hypolimnion (bottom). These layers exist due to temperature and density differences in water.
• Water's role in the water cycle.

Water Usage

• Oceans hold 97.41% of all water on Earth.
• Freshwater accounts for 2.59%. Only 0.003% of water is readily available on Earth, mostly in lakes.

Atmospheric Science & Pollution

• Air pollution is defined as the presence of one or more contaminants in amounts and durations harmful to human, animal, or plant life or property.
• Primary pollutants: Emitted directly into the environment (e.g. CO, NOx, HC from motor vehicle exhaust).
• Secondary pollutants: Formed by reaction in the environment (e.g. O3, PAN in photochemical smog).
• Major environmental issues related to atmosphere: local (e.g., heat island), regional (e.g., acid rain), and global (e.g., ozone layer depletion, global warming).
• Major Pollutants in the atmosphere: Sulfur oxides (SOx), Nitrogen oxides (NOx), Carbon monoxide (CO), Carbon dioxide (CO2), Volatile organic compounds (VOCs), Particulate matter (PM), Toxic metals, and Chlorofluorocarbons (CFCs).
• Additional pollutants: Ammonia (NH3), Odors (garbage, sewage, industrial processes), Radioactive pollutants (nuclear explosions, natural processes like radon), Peroxyacetyl nitrate (PAN).
• Heat Island phenomenon: A metropolitan area is significantly warmer than its surrounding rural areas owing to the lack of vegetation, heat generated from buildings and people as well as from roads.
• Temperature inversions (from heat island effects): A stable layer of warm air above cooler air prevents pollutants from rising. They get trapped in valleys or near mountains.

Ozone Layer Depletion

• CFCs, halogens, and other ozone-depleting substances (ODS) lead to ozone depletion in the stratosphere.
• CFCs were widely used in refrigerants, aerosols, and cleaning agents.
• Ozone depletion results in increased levels of UV radiation reaching Earth's surface which damages living organisms, crops, and animals.
• Effects of depletion: Increased skin cancer rates, cataracts, harm to vegetation, and effects on animal populations.

Acid Rain

• Acid rain is precipitation with an unusually low pH caused primarily by human-produced sulfur and nitrogen compounds reacting in the atmosphere with water.
• Acid rain damages the environment (soils, water), structures (buildings, statues), and ecosystems.
• Natural sources that produce acid components exists: volcanoes and dimethylsulfide, from various biological processes.

Global Warming

• Global warming refers to an increase in the average temperature of Earth's surface.
• It has been observed for centuries and is now increasingly considered related to greenhouse effect.
• Gases in the atmosphere trap heat improving the average temperatures of the planet.

Greenhouse Effect

• Solar energy is absorbed by the Earth.
• Heat is radiated back into space.
• Greenhouse gases reflect some of this heat energy back towards Earth making the planet warmer.

Human Impacts on Global Warming:

• Greenhouse gases (e.g. CO2, Methane, Nitrous oxide, Florinated compounds).

Natural Impacts on Global Warming:

• Volcanoes, water vapor, clouds.

Who's Responsible : Greenhouse gasses emissions

• Burning fossil fuels is a primary source of greenhouse gases.
• The US has high emissions.

Ice Melting

• Observed reductions in ice coverage.
• Related to global warming impacts.

Changes in Global Temperature

• Global average temperatures have risen considerably.
• Changes are often measured in graphs showing trends through time.

What you have to do?

• Individuals and governments have a shared responsibility for improving environmental conditions.
• Prevent environmental degradation.
• Consider ways to lower emissions and lessen the effect of environmental degradation.