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Environmental Problems
Environment: is everything that effects living organisms.
Ecology: is biological science that studies relationship between living
environmental problems include:
Ozone depletion. Acid rains and smogs.
Ozone (O3):
– Highly reactive gas – harmful to breath – 3 atoms of oxygen
1- 90% of the O3 is in Stratosphere and it is called Ozone Layer
2- O3 absorbs a band of ultraviolet (UV) radiation called UVB
Ozone Layer (O3):
– A region of Earth’s stratosphere – At an altitude of about 10 KM
1- Absorbs and protect the earth from most of the Sun’s UV radiation.
2- absorbs much of the radiation between 240 and 310 nm
The atmosphere has 4 layers:
1- Troposphere 2- Mesosphere 3- Stratosphere 4- Thermosphere
Stratospheric ozone is good ozone.
It forms about 10-30 miles above the Earth’s surface.
Ozone harms human health and the environment when it forms
close to the ground.
The most significant things that cause ground-level ozone to form
are:
o NOX and VOCs (from mobile source emissions and industrial
processes), and UV radiation (from sunlight).
o People with respiratory conditions such as asthma, or those who are active outside on days when ozone amounts are
high can feel shortness of breath, wheezing, and coughing. o We can all take actions to help protect ourselves and reduce the damaging effects of this pollutant on our health and
environment
The Reasons of Ozone Depletion
1- Excessive use of CFCs 2- Not water soluble 3- Quite unreactive 4 –diffuse easily to the stratosphere
Ozone layer depletion
The thinning of the ozone layer present in the upper atmosphere.
This happens when the chlorine and bromine atoms in the
atmosphere come in contact with ozone and destroy the ozone.
One chlorine can destroy 100,000 molecules of ozone.
Some compounds release chlorine and bromine on exposure to
high ultraviolet light, which then contributes to the ozone layer
depletion.
Such compounds are known as Ozone Depleting Substances
(ODS).
Discovery of Ozone Depletion
In 1970, Crutzen revealed that naturally occurring nitrogen oxides destroy ozone
In 1974 Rowland and Molina discovered that chlorine from chlorofluorocarbons (CFCs) may be depleting the supply of ozone in the upper atmosphere by reacting with it.
Revealed in 1978
First published paper in 1985
“Ozone Hole Watch” website launched in 1999
Ozone Depletion solution
• Montreal Protocol was issued in 1987, reducing the substances using the CFCs
• Banning the production of CFCs in 1996 was agreed and implemented by 100 nations.
• Ozone depletion will continue for some time because of the tremendously unreactive nature of CFCs.
• Hydrofluorocarbons (HFC-134a) are the alternatives
Acid rains and Smog
• Rain is naturally slightly acidic pH 5.6.
• CO2 in the air dissolving into the water forming carbonic acid.
• However, when sulfur and nitrogen oxides dissolve in the rain they
form sulfuric and nitric acid and can have a very low pH (1-3)
• pH scale is logarithmic, pH1 is x10 more acidic that pH 2, and x100
stronger than pH 3
Sulfur (Acid rain)
• Sulfur dioxide is a by-product of the burning of coal or oil.
• It reacts with water vapor in the air to form sulfuric acid (H2SO4) • Sulfuric acid (H2SO4) It is primarily responsible for acid rain. Smog
• Nitrogen oxides NO2 come from car exhaust, coal power plants,
and factory emissions.
• Volatile organic compounds are released from gasoline, paints,
and many cleaning solvents.
• When sunlight hits these chemicals, they form airborne particles
and ground-level ozone—or smog.
Photochemical smog: also known as summer smog, is a type of smog that is produced when UV light originating from the sun interacts with the oxides of nitrogen present in the atmosphere.
Most seen in highly populated cities that are placed in relatively warm climates.
Furthermore, photochemical smog is most prominently visible during the mornings and afternoons.
Global warming is the progressive increase of Earth’s average temperature
Effects of global warming:
1- Rise in sea levels 2- melting of glaciers 3- severe storms
4- Climate changes 4- Loss of habitat for tempe-sensitive species
Climate Change
• Temperatures are rising, especially in winter.
• Extreme rainfall and flooding events (24-hr and 7-day) are more
frequent.
• Extreme droughts and massive wildfires are more common
• In rural communities, forests and farmland are impacted, making
crops and food scarcer and more expensive for all
The Greenhouse Effect
• Greenhouse gases are the mixture of carbon dioxide, water vapor, methane, nitrogen oxide and ozone in the atmosphere.
• These gases are what keeps the earth a warm plant, but in excess these gases cause global warming.
Cause of Global Warming
1- Burning of Fossil Fuel 2-Deforestation 3 -Livestock Farming
Photosynthesis:
• is the process by which plants and other microorganisms trap light energy from the sun.
• It takes Carbon dioxide and combines it with water, using light energy to produce glucose and oxygen.
• It is done by plants and some bacteria, but not by animals or fungi.
Deforestation: clearing of forests for farming and human settlements
• 25% of carbon dioxide added to the atmosphere comes from cutting and burning forests in the tropics.
• Replanting helps decrease carbon dioxide levels
Biggest sources of carbon dioxide emissions:
1-Industry 2-Commercial 3-Transportation 4-Residential 5-agricultural
During the Conference of Parties (COP) 19 meeting on Climate change. They committed to address climate change from an economic, social, and environmental point of view, including:
Implementing commercial clean energy projects.
Making investments into clean technologies.
Making clean energy accessible to all.
76% of the UAE’s Ecological Footprint is due to CO2 emissions, resulting largely from consumption of energy and desalinated water.
The UAE and Actions on Climate Change
1- Peaceful Nuclear Power 2- Energy Efficiency and Conservation 3- Renewable Energy 4-Transport 5-Building Design 6-Carbon Capture and Storage
Challenges facing the UAE to reduce its emissions
1-Cars dependent country 2-High provision of roads for car usage 3-High demand for AC 4-Low provision of public transport
Masdar Initiatives:
1- Solar Powered Hydrogen Fueling Station 2-Sustainable Buildings (Eco Villa) 3-EV Rapid Charger Station 4- Seawater Agriculture
Plastic to Fuel–Masdar Park–Eco Bus–Masdar Farms–Air to Water—Seawater Energy—Driverless cars (Navya)
UAE powers towards sustainable future
Major developments that have taken place from 1971?
Health – life expectancy in the UAE increased to now exceed 76 years. mortality indicators have all improved.
Education – 40 years ago, only 48% of UAE adults were literate. today, over 93% are literate, with nearly equal rates for men and women.
Economy – UAE’s GDP has now exceeded 1 trillion dirhams, from 11 billion dirhams in 1973. The UAE has the world’s third highest GDP per capita.
Infrastructure – world-class infrastructure.
Travel & Tourism – the UAE one of the leading tourist destinations worldwide.
Environment – CO2 emissions per capita have been declining, from 80 metric tons per capita in 1971 to 31 metric tons per capita in 2007