Human impact Signs of environmental crises. Global environmental crises Causes of Environmental degradation Drivers of environmental degradation Impacts of environmental pollution Solving environmental problems.
The term "environment" means thesurroundings of an organism.The total environment of an organism isthe sum total of the biotic and abioticenvironments.
Natural environment is of crucial importance for social and economic life.
Humans are one partof a complex worldecosystem.Humans dominate theplanet and all its life.Human actions havea profound impact onthe environment
In many parts of the world : Forests are shrinking Water tables are fallingDeserts are expanding Rivers are running dry Soils are eroding Fisheries are collapsing Rangelands are Coral reefs are deteriorating disappearingThe lower atmosphere is Life forms are vanishing warming Pollutants and waste are Glaciers are melting rising Sea levels are rising Tropical diseases are Storms are destructive emerging
Disaster Source/place Month & year No. of victimsMinamata mercury Chisso chemical 1950s 2,265 deathspoisoning Corporation, JapanSeveso disaster - Chemical July 193 Human deathsDioxin cloud manufacturing 1976 3,300 animal deaths Industry, ItalyBhopal gas leak Union Carbide December 35,000 deaths pesticide plant 1984 .Bhopal, IndiaChernobyl nuclear Nuclear power plant April 4000 cancer deathsdisaster Ukraine 1986Exxon Valdez Oil tanker accident in March 250,000 sea birdsOil spill-Prince William Alaska coast 1989 2800 sea otterssound 300 seals- deathsSuper cyclone Orissa ,India October 10,000 deaths 1999Asian Tsunami Indian ocean December 227,898 deaths earthquake- 2004 11 countries
Pollution of ecosphere, Global warming Deforestation Loss of ecosystems Loss of biodiversity None of the above occur alone, each change triggers another
Environmental impact = population size X per capita consumption X pollution and resource use per unit ofEnvironmentalimpact refers to consumption.the alteration ofthe naturalenvironment byhuman activity
Professor Paul Ehrlich is a biologist and author of the best-selling book ‘The Population Bomb(1968)’. Paul Ehrlich is one of the worlds leading experts on population. He is renowned for his role in helping the world to think about resource scarcity and the impact of an ever- increasing population on demand for natural resources.
Environmental impact(I) = population(P) x consumption(C)Or I = PX CEnvironmental impact formula I=PATWhere I= environmental impact P=the number of people A= affluence=average resource use per person T= technology=environmental effects of technology
In the early 1970s, ecologist Barry Commoner published a book ‘The Closing Circle’. He insisted that the rapid growth of industry and technology have persistent effect on all forms of life. Based on Barry Commoners warnings, Time magazine warned in its cover story on Commoner (February 2, 1970), "the price of pollution could be the death of man." Barry Commoner’s four laws of ecology : Everything is connected to everything else. Everything must go somewhere. Nature knows best. There is no such thing as a free lunch.
Yoichi Kaya (1990)- Global CO2 emissions = Japanese energy (population)x(GDP/population) x(energy use /GDP)x (carbon economist emission/energy use). Human impact on environment can be calculated through 4 factors 1. Population 2. Gross domestic product /person 3. Energy use / unit of GDP 4. Carbon emissions/ energy unit.
Population growth Human Environmental impact crisisPe rc ap it ac on y og su ol m pti ch n o n Te
Human population growth is the number one threat to the worlds environment. The environmental impact of human activity is a function of population, consumption and technology.
The world’s population presently grows by about 250,000 people per day.
The human population is exceeding the carrying capacity of our planet.
Increasing human population and industrial activities have led to problems associated with the pollution of air, water, and soil.
a high birth rate a relatively low death rate due to advances in medicine and technology. more agricultural production, restrictions on women’s rights, and prohibitions on birth control .
According to the law of population growth, no population can continue to grow exponentially forever.
Earth has finite resources. Its ability to sustain the growing population is finite. Its ability to provide food and energy is finite. Industrialized nations consume more resources per capita
Global resource consumption is rising rapidly. This consumption is driven by population growth and rising wealth. As a result this ever-increasing consumption, emissions and wastes pollute the earth and destroy the ecosystems.
The burning of fossil fuels has almost quintupled since 1950. The consumption of freshwater has almost doubled since 1960. The consumption of cereals has more than doubled in the last 30 years. World meat consumption has tripled since 1961. The consumption of fish and fishery products has increased more than five fold since 1950.
Improved quality of life Greater economic growth Rapid and bulk production of goods Better transportation faster communication Comfortable housing Enjoyable recreation Pollution of life support systems Degradation of natural habitats Global warming & climate changes Depletion of natural resources Impact of industrial agriculture Toxic contamination Depletion of ozone layer
Deforestation is the removal trees from a forest and converting the land for other use. Tropical rainforests are disappearing at an alarming rate. Destruction of forest leads to extinction of species
The gradual transformation of healthy fertile land into a desert. Desertification is usually caused by climate change or by destructive use of land .
Air pollution is made up of a mixture of gases and particles that have been released into the atmosphere by man- made processes.. We breathe about 2 gallons of air every minute. A typical human lifespan can be reduced by 1-2 years from inhaling polluted air.
Global warming is a gradual rise of the earth’s temperature. It is a function of the greenhouse effect. There is a rise in global mean surface temperature by 4 -6 degrees C..
Non-greenhouse Greenhouse gases gases (GHGs) Carbon dioxide (CO2)- burning Nitrogen,N2 fossil fuels and wood. Nitrous oxide (NO2)- Oxygen,O2 fertilizer use and decomposition of animal wastes. Argon,Ar Methane (CH4)- sediments, swamps, landfills, and in flooded rice paddies. Chlorofluorocarbons (CFCs)- Freon (a refrigerant) Halons, such as halocarbons- fire extinguishers. Water vapor -clouds reradiate heat back to Earth.
Combustion of fossil fuels Volcanic eruptions Land use changes & deforestation Sources of global Power generation & oceans carbon dioxide transport emissionsBreathing & Industrial processesDecomposition ofplants and animals Forest and wild fires
The atmospheric carbon dioxide is the principal climate –altering gas. Carbon dioxide absorb heat radiation( infrared) from the sun and emit towards the earth. Elevated CO2 means more heat will be radiated. Water vapor act as an amplifier of warming.
Greenhouse gases have been essential to the survival life on planet earth. They trap heat and cause the earth to warm. Human activities alter the proportion of GHGs in the atmosphere. They add more GHGs and induce more heat trapping by the atmosphere.
Gas formula Contribution, %Water vapor H2O 36-72 %Carbon dioxide CO2 9-26%Methane CH4 4 – 9%Ozone O3 3 – 7%
Regions World population,% Responsibility for Global warming, %The West 15 46Central/Eastern 7 19EuropeThird world 78 35 Source: New International, April 1990,
Chemical Conc. In Atmospheric GWPGreenhouse formula 2005 life , years gasCarbon CO2 379ppm variable 1dioxideMethane CH4 1774ppb 12 21Nitrous N2O 319ppb 114 310oxide
1. Frequent temperature extremes ( killer heat waves).2. Changing rainfall patterns. 3. Rise in sea levels.4. Frequent storms and coastal flooding 5. Drought 6. Air pollution made worse by warming. 7. Asthma, bronchitis, emphysema complications 8. Expansion of Deserts. 9. Unable to contain spread of infectious diseases
Sun light☼ The term smog was derived from the words ’fog’ and ‘smoke’. The term was first used in 1905 by H.A. Des Voeux. VOCs and NOx react in presence of sunlight to produce ozone and PAN (peroxy acetyl nitrate)
Los Angeles smog London smogPhotochemical smog Sulfurous smogSummer smog (July1973) Winter smog (Decem 1952)Petroleum combustion Coal combustionAutomobile exhaust Industrial sourcesLight-brownish in colour Yellow-black in colourSecondary pollutants – H2So4, O3, PAN, Organics, acidssulfate aerosolsRespiratory distress Lung disease
Ozone (O3)Stratospheric ozone Tropospheric ozone-upper atmosphere (ground –level ozone)-good ozone -lower atmosphere -bad ozone Absorb UV-B rays Greenhouse effect Global warmingPrevent skin cancerCataract etc. Global climate change
Ozone depletion results in ‘ozone hole’ in upper atmosphere. During the 1980s, scientists discovered a "hole" in the ozone over Antarctica. Breathing O3 affects both the respiratory and nervous systems, resulting in respiratory distress, headache, and exhaustion. Ozone is damaging to plants, resulting in leaf mottling and reduced growth. Hazards of UV radiation include skin cancer and cataracts and depression of the immune system. Each 1% drop in ozone is thought to increase human skin cancer rates by 4-6%.
Acid rain is the term used to describe polluted rainfall (acid pollution). Acid rain is directly linked air pollution. Acid rain is defined as the precipitation with pH less than 5.6. The phenomenon of Acid rain is becoming a global environmental problem.
Acid rain is mainly due to the reaction of water vapor with sulfur dioxide and the oxides of nitrogen. Acid rain often has a pH as low as 2.4 2SO2 + O2 + 2H2O → 2H2SO4 4NO2 + O2 + 2H2O → HNO3
Sterilization of lakes and forests.Reducing the populations of smallinvertebrates and decomposers.Reducing agricultural yields.Causing structural damage by corrodingmarble, metal, and stonework.Leaching heavy metals from the soil intodrinking-water supplies.Increases in lung cancer and coloncancer.
Loss of soil quality and productive capacity Loss of organic matter, Reduction of vegetative cover Loss of soil life
Degradation results in soil compaction and erosion, a reduction in water holding capacity and increased salinization. Soil is getting thinner , “tired” and “worn out”.
Land pollution is caused by poor agricultural practices, usage of pesticides, mining for coal and minerals, and dumping industrial and urban wastes.
Approx. 700 million people in 43 countries suffer as a result of water scarcity. Nearly 1 billion people lack safe drinking water. Half of the world’s 500 major rivers are polluted. 75% of India’s lakes and rivers are too polluted for safe use.
Water shortage - levels of available water do not meet minimum requirements. Water scarcity – the relationship between demand for water and its availability. Water stress – decline in water quality. Water security – access to adequate quantity and safe quality.
Toxicity- acute / chronic – damages aquatic / human lifeChanges in Sub-lethal toxicityWater chemistry Endocrine disruption / Changes in biodiversity Effects of water Acidity/alkalinityEutrophication pollution Changes pH regime Altered water Spread of microbial temperature diseases Deoxygenation- Lack of O2 in water
Biodiversity is our living wealth Biodiversity is a global resource. It is a vital part of the earth’s life-support system. Biodiversity is the mainstay of agriculture , forests and fisheries. Biodiversity today is the result of 3.5 billion years of evolution.
Biodiversity is under threat Biodiversity is under threat globally, nationally and locally. There are TWO main causes of Biodiversity loss: 1.Destruction of species 2.Destruction of habitats
Assessment Risk analysis Public education Political action Follow-through
The gathering of information Performing experiments Make predictions
Use the available information to predict the consequences of environmental degradation. Evaluate the potential to solve the environmental problems.
Inform the public. Explain probable costs and results. Present alternative actions.
The public, through officials, selects and implements a course of action.
Prevent pollution. Reduce waste. Try composting of biodegradable garbage. Use water, energy and natural resources efficiently. Maintain the diversity of life. Protect the worlds natural, cultural and indigenous heritage. Support environmental education. Support local action and community participation.
Dr.B.Victor is a highly experienced professor, recently retired from the reputed educational institution- St. Xavier’ s College, Palayamkottai, India-627001. He was the dean of sciences and assistant controller of examinations. He has more than 32 years of teaching and research experience He has taught a diversity of courses and guided 12 Ph.D scholars. comments to : email@example.com