Monday, March 31, 2014

Killer chemicals in the environment

Everything in the world around us is made up of chemicals. Living organisms such as plants, animals and humans are all made up of chemicals. Chemicals are integral part of daily life of people around the world. Use of chemicals around the world is increasing with the growing production in countries. Chemicals have played a major role in the development of human societies – in agriculture and food; in industry and transport; in housing and in health. The entire World has poisoning itself with the “miracle of modern chemistry” as found in all the pesticides, plasticizers, additives, preservatives, detergents and other chemicals. Chemical impacts are complex, unknown.  Chemicals can enter the air, water and soil, when they are produced, used or disposed. These chemicals are known to exhibit various harmful effects on human biology, covering everything from neurological and infertility problems to cancer and hormonal disorders.


Over 11 million chemical substances are known and some 60,000 to 70,000 are in regular use. Between 200 and 1000 chemicals are produced in excess of one tonne annually. Currently new chemicals are entering the market at the rate of about 600 each month (or over 7000 per year) (Lillibridge 1997). Of the 80,000 chemicals in general use, only about 3,000 have been stringently tested for health impacts on humans. A new study from the University of California, San Francisco reveals that 100 percent of expectant mothers are contaminated with highly toxic synthetic chemicals. The study, published in Environmental Health Perspectives, concluded, “certain PCBs, organochlorine pesticides, PFCs, phenols, PBDEs, phthalates, polycyclic aromatic hydrocarbons (PAHS) and perchlorate were detected in 99 to 100% of pregnant women.”
Chemical contamination may originate from manufacturing, processing, transportation, storage, distribution, use and waste disposal. Chemical incidents can happen anywhere and at anytime. Lorries can spill their contents, rail tankers can overturn and clouds of chemical vapour can drift anywhere in the wind.  More than 4 billion tonnes of hazardous chemicals are moved each year around the world by motorway, rail, and pipeline systems.

PBT  chemicals

Persistent, bioaccumulative and toxic (PBTs) substances are a class of compounds that have high resistance to degradation by abiotic and biotic factors, high mobility in the environment and high toxicity to cause birth defects, cancers and other health effects. PBTs transfer easily among air, water and land and cross human boundaries. The U.S EPA has identified 31 as PBTs (28 organic chemicals plus 3 metals and their compounds) e.g., Polychlorinated chemicals (e.g., DDT, PCBs), Poly brominated chemicals (e.g., organo-bromines), Poly fluorinated chemicals (e.g., organoflurorines), benzopyrene, alkyl-lead and mercury compounds.

PAH chemicals

Polycyclic aromatic hydrocarbons are a family of long lived chemicals that cling to sediments, bioaccumulate in fats and difficult to degrade. PAHs are similar to PCBs and other polychlorinated chemicals but PAHs do not contain chlorine.  They are produced by incomplete combustion of fossil fuels and wood burning. Natural PAH sources include forest, grass fires and volcanic eruptions. Air borne PAH particulates settle on the water, food, crops and other vegetation. The route of 90% of human exposure to PAHs is from food consumption, especially leafy vegetables and unrefined grains. Breathing air borne PAH particulates cause respiratory distress. Benzopyrene is a best known human carcinogen.


Volatile organic chemicals (VOCs) are chemicals that transform quickly from liquid to vapour.  VOCs are found in paints, paint thinners, lacquers, hair sprays, perfumes, oven cleaners and dry cleaning liquids. VOCs also emanate from wood finishes, plywood, panelling, fibreboards, particleboards, carpeting, furniture, permanent- press fabrics, draperies and mattress ticking. Motor vehicle products such as gasoline and oils emit VOCs. VOCs contribute to the formation of ground level ozone.  VOCs are soluble in water which can result in pollution. VOCs are flammable and can be toxic to humans and wildlife. One of the most widespread VOCs is formaldehyde, classified as a probable human carcinogen by the U.S EPA. It causes nasal cancer in laboratory animals and it irritates the eyes, nose, throat and lungs. Another common VOC, chloroform is a by-product of the process used to sanitise drinking water, in some water treatment plants. VOCs that accumulate in air tight buildings/cabins of jet planes contribute to ‘sick building syndrome.’


They form the basic raw materials in the manufacture of a large number of materials such as fertilizers (ammonia), plastics, fibres, rubbers (nylon, polyester, acetate etc.), and paints. They have also been used in the manufacture of pesticides, lubricants, adhesives and solvents. The production processes of ammonia, acetone, ethyl alcohol, acetic acid, acetic anhydride, glycerine significantly based on petrochemicals. Nearly more than 80% of the organic chemicals used in chemical industry are based on petrochemicals.

Some notable injurious chemicals

Phthalates are chemical plasticizers. Pharmaceutical pills are often coated with phthalates to give them a shiny finish. They’re also used in children’s toys, medical devices, personal care products, sunscreens and even sex toys. On the personal care side, phthalates are found in perfumes, eye shadow, liquid soap, nail polish and hair spray. Phthalates are known as “endocrine disruptors” because they interfere with normal endocrine system function — potentially leading to obesity and birth defects. Oxybenzone, the active ingredient in many sunscreens, is a hormone disruptor and could even damage the nervous system. Perchlorate, also known as the “rocket fuel chemical,” is used in the manufacture of automobile airbags and other vehicle parts. It’s also present in many fireworks, and is frequently found contaminating the water supply. Metal like mercury is highly toxic and its compound methyl mercury is a confirmed neurotoxicant. It builds up in the food chain, notably in certain food fishes and enters the human food chain. It damages the developing brain. It is also genotoxic: it is known to pass through the placental barrier and the blood-brain barrier putting the unborn at risk. It can cause permanent damage to the central nervous system, lungs and kidneysPossible sources of metal contamination include residues migrating into foods from soldered cans, leaching from utensils, contaminated water, glazed pottery, painted glassware and paints.

General characteristics of hazardous chemicals

Toxicity is the inherent property of a chemical to produce adverse biological effect.
Mobility is the ability of a chemical to travel through the environment.
Persistence is the ability of the chemical to remain in the environment for a long time.
Synergistic action - the combined effect of two different chemicals is greater than the individual effect.
Bioaccumulation is the selective accumulation in the bodies of living organisms.
Biomagnification – the concentration of bioaccumulated chemical in the bodies of living organisms increases as they travel up the food chain.

“Be aware of our potential exposure to hazardous chemicals in the home, workplace and environment.”

The Stockholm Convention and POPs

The Stockholm convention on persistent organic pollutants (POPs) 2001 is an international agreement by the nations of the world to address the global chemical pollution. It was signed by 128 country parties in 2001 and come into force from May 2004. POPs are chemical substances that persist in the environment, bioaccumulate through the food web and pose a risk of causing adverse effects to human health and environment.  POPs include 12 chemicals (dirty dozen) such as the organochlorine pesticides: DDT, endrin, dieldrin, aldrin, chlordane, toxaphene, heptachlor, hexachlorobenzene, mirex; and the industrial chemicals and by-products: PCBs, dioxins, and furans. The Convention aims to eliminate the production, use and emissions of POPs.

Green chemistry

Green chemistry is the science – based design of chemicals, chemical processes and products that minimize the use and generation of hazardous substances.
12- Guiding principles of green chemistry
1.       Prevention –prevent waste generation.
2.       Atom economy –design efficient design synthetic methods.
3.       Less hazardous chemical syntheses- design production methods – less toxic by-products.
4.       Design safer chemicals-minimum toxicity of products.
5.       Use safer solvents and auxiliaries.
6.       Design for energy efficiency.
7.       Use renewable raw materials.
8.       Reduce derivatives
9.       Use catalytic reagents.
10.   Develop in-process control of hazardous substances.
11.   Prevent the potential for chemical accidents.
12.   Design for chemical degradation.

Warnings for safe chemical use

Stay informed – be aware of the characteristics for e.g., toxicity of chemicals.
Choose non-toxic or less-toxic household products – follow instructions and warnings for safer use.
Make healthy diet and life style choices – avoid tobacco products. Choose fresh foods.
Reduce the potential for indoor and outdoor chemical exposures.
Get involved – participate in public policy development. 

Sunday, March 30, 2014

Techniques of creative thinking

 Creativity is ‘having the power to create’ or ‘doing things differently.’ Creativity is an ability to generate new ideas or concepts that are both innovative and functional.  Generally creativity is viewed as a special mental power to solve difficult problems (process) and generate spectacular ideas (products). The process of creativity often leads to the creation of products that are novel and valuable. Creativity demands imagination, ability to improvise, the courage to combine known factor or thing to create something new. Creativity is the key for achieving a better standard of living.  Creativity will make and keep one’s life interesting. Creativity can be developed through training (education) and application. Creativity requires 6- interrelated resources such as intellectual abilities, knowledge, styles of thinking, personality, motivation and environment. Creativity shows a set of human characteristics like ‘inventiveness,’ ‘innovativeness,’  ‘productive thinking,’ ‘an act of discovery,’ ‘newness,’ ‘novelty,’ and ‘originality.’  Creativity resembles thinking –out-of-box or reaching over the moon. Tony Buzan said that creativity is as essential to your survival as breathing. Berk (2002) defined creativity as the ability to produce work that is original, but still appropriate and useful. The source of creativity is both intrapersonal (cognition, personality) and social factors that support creativity.

“More creativity is the only way to make tomorrow better than today.” – Anon.


Richards (1985) defined creativity as ‘the personal discovery process, partially unconscious, which leads to new and relevant insights.’Creativity is the ability to generate new ideas by combining, changing or reapplying existing ideas. Creativity is possible in all areas of human activity including  the arts, sciences, at work, at play and in all other areas of daily life. Creativity is the process of sensing problems or gaps in information, forming ideas or hypotheses, testing and modifying this hypothesis, and communicating results.

Types of creativity (Boden,1998)

The combinational creativity involves new combinations of familiar ideas.
The exploratory creativity involves the generation of new ideas by the exploration of structured concepts.
The transformational creativity involves the transformation of some dimension of the structure so that a new structure can be created.
Creativity may be two types such as cognitive and artistic creativity. Artistic creativity consists in the creation of artwork and expressing one’s ideas and emotions through various forms of art. Cognitive creativity is a matter of coming up with solutions to a practical or theoretical problem. The examples include creating a new scientific theory or launching a innovative product.

Forms of creative discoveries

Koshland (2007), the former editor of Science, categorizes three forms of creative discoveries: charge, challenge and chance discoveries. Charge discoveries solve problems that are quite obvious. Charge discoveries occur when someone “sees what everyone else has seen, and thinks what no one else has thought e.g. Einstein’s theory of relativity. Challenge discoveries occur from the accumulation of facts or concepts and the discoverer perceives a new concept or theory that pulls these together onto one coherent whole e.g. Darwin’s theory of evolution. Chance discoveries occur when people have what Louis Pasteur called ‘the prepared mind’ e.g. discovery of penicillin and x-rays.

Origin of creativity (Jane Henry 1991)

Grace – creativity comes through divine inspiration.
Accident – creativity arises by serendipitous good fortune.
Association – creativity occurs through the application of procedures from one area to another.
Cognitive – creativity relies on normal cognitive processes such as recognition, reasoning and understanding.
Personality – creativity is something that we are born with.

Factors contributing to creativity

A gift for associating thoughts and feelings in unusual combinations;
An attitude of playfulness, openness and flexibility;
Knowledge of how the creative process works;
Skill in using the tools of the trade;
Persistent effort to keep trying until the result is satisfactory; and
A favorable setting in which creativity can find free expression.

Creative attitude

Domain –relevant skills – includes talents and competencies that are valuable for working in the domain. An example of Michelangelo’s skills in shaping stone, developed when he lived with a stone cutter’s family in the childhood.
Creativity –relevant processes – includes work habits and personality traits such as John Irving’s habit of working 10-hours to write and rewrite and rewrite until he perfected his stories.
Intrinsic task motivation or a deep curiosity and fascination with the task – this aspect of creativity can be greatly influenced by the social environment by supporting autonomy, stimulating curiosity, encouraging fantasy and providing challenge.

Qualities of creative people

  1. General intelligence – powers of analyzing, synthesizing and valuing; ability to store and recall information.
  2. Highly self motivated – a high degree of autonomy, self sufficiency and self-direction.
  3. Negative capability – the ability to hold many ideas often contradictory.
  4. Curiosity – sustained curiosity and keen powers of observation and good listening skills.
  5. Independence of mind – marked independence in making judgments.
  6. Ambiversion – ambivert in character (intro/extrovert combination)
  7. Wide interests – a broad range of interests especially the ones with creative dimension.

Intellectual characteristics of creative people

Fluency – is the ability to generate a large number of different ideas rapidly.
Originality – is the ability of generating unusual answers to questions, responses to situation and interpretation of events.
Flexibility – is the ability to move from on frame of reference and one method of approach to another.
Tolerance of ambiguity – is the ability to live, perform and be comfortable with unclear situations, unfamiliar methods and unusual resources.
Playfulness and humour are hallmarks of the highly creative people.

Technique for generating more ideas (fluency)

Bob Eberle (1971) developed the acronym SCAMPER for generating more ideas. Each letter represents a key word that stimulates the production of ideas.
S – substitute; C – combine; A – adapt; M – modify, magnify, minify; P – put to other uses; E – eliminate; R – reverse, rearrange.

Personality characteristics of creative people

Strong work motivation – they are positive, enthusiastic and optimistic about the work/ problem undertaken.
Independence and autonomy – they are strongly self-disciplined , independent and self-assertive in solving new and unfamiliar problems.
Nonconformity both intellectually and personally is the central characteristic of highly creative people.
High energy – they have greater motivation to work on several projects at once.

Stages in the Creativity  process (Claxton, 1999)

There are 4 steps in any creative process: preparation, incubation, illumination and verification.
Preparation – it includes information gathering, talking to people about aspects problem, experimentation and doodling. Louis Pasteur said that chance only favors the prepared mind.
Incubation – it appears to be gestation period in which the process goes on subconsciously and takes a different shape.
Illumination – it is the sudden flash of understanding in which the solution appears in the mind.
Verification - the idea created must pass the tests of validity, reality, utility, reliability, cost, time and acceptance in market.

Methods of  creative thinking 

Analogies - creative people use resemblance in form or function of viewing essentially two different things.
Modelling - model is a primary type of anything (prototype), a pattern, a standard and an example. An individual can translate his experience into a model of the world is through action. Modelling can be used for the identification of a problem.
Reframing – changing the frame in which a person perceives events in order to change the meaning. Reframing is ‘thinking about things differently’ or see a new point of view o to take other factors into consideration. It can be content reframing or context reframing.
Lateral thinking – tries to restructure the pattern by putting its parts together in different ways. It explores multiple possibilities and approaches instead of pursuing a single approach.  It is divergent thinking.
Critical thinking - encompasses a variety of cognitive skills such as analysing, synthesizing, applying and evaluating information. Both critical and creative thinking are complementary. In productive problem solving, one can creatively generate ideas and critically evaluate ideas. The combination of critical and creative thinking is considered ‘Good thinking.’ 
Synectics – is a technique that uses analogies and metaphors in a systematic way to change the frame of reference in which the problem is perceived.
Forced associations – a number of techniques build upon the idea of the association of unlikely elements.
Random associations – the associative capabilities of the human mind are so great that bringing two randomly selected elements together, most people make sense of them.
Matrices –a two-dimensional or three-dimensional matrix using problem and solution attributes as its headings is a convenient tool for examining each intersections of column and rows one at a time.

Characteristics of creative thinking

 Creative people have the ability to make remote associations between ideas with divergent thinking. They are flexible in their thinking and switching back and forth between conventional and unconventional ideation to generate original novel ideas that appropriate to the task at hand. Creative people are very flexible in jumping from idea to idea. They are willing to take risks.
Creative thinking is associative thinking. Creative thinking requires divergent thinking before convergent thinking.Creative thinking is thinking outside the (negative thinking) box. Creative thinking is an active version of wishful thinking.Creativity can be improved through training.
The positive benefits of creativity include self-directed learning, self-expression, personal integrity, personal growth and well-being. Creative thinking provides a sense of control over the external world.
         "On your creative journey, you travel through the hearts of your audience."

Key facts of neuroscience research on the act of creation

1. Instinct plays a leading role in complex decision making.
2. Eighty percent of our grey matter is dedicated to unconscious thought.
3. Imaginative play is one of the most direct means of activating our creativity and problem solving abilities.

Quotes on creativity

"Creativity is thinking up new things.Innovation is doing new things." -Theodore Levitt.

"Creativity is allowing yourself to make mistakes.Art is knowing which ones to keep."
 -Scott Adams.

"Creativity is inventing, experimenting, growing, taking risks, breaking rules
 and having fun." -Mary Lou Cook.

"Creativity is the sudden cessation of stupidity." -Edwin Land.

“Creativity is contagious, pass it on.”-Albert Einstein.

“Creativity is intelligence having fun.”- Albert Einstein.

“Imagination is more important than knowledge.” -Albert Einstein.

“Play is the highest form of research.”-Albert Einstein.

Saturday, March 29, 2014

What is the future of global biodiversity?

A definition of biodiversity is ‘the spatial and temporal variability of the structure and function of living systems’. Biodiversity drives the functioning of ecosystems through countless reciprocal interactions with the physical and chemical components of the environment. Biodiversity is the foundation and mainstay of agriculture, forests and fisheries as well as soil conservation and water quality. Biodiversity is our wealth and a vital means of sustenance.

 Wilson (1993) said “biodiversity is vital to healthy forests, while proper forest management is vital to the maintenance of biodiversity.”  At least 40% of the world’s economy and 80% of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for the discovery of new medicines, economic development and adaptive responses of species to climate change (The convention about life on earth).

The present biodiversity is the result of 3.5-4.0 billion years of evolution. According to some estimates there could be as many as 30-50 million species on the planet earth. About 1.7 million of earth’s species have been identified and designated with a scientific name. About 6% of the identified live in boreal or polar latitudes, 59% in the temperate zones and the remaining 35% in the tropics. Our biodiversity is under threat globally, nationally and locally.  Biological diversity is diminishing all over the earth. Large scale global extinction of species occurred in the 20th century at a rate that was a thousand times higher than the average rate during the preceding 65 million years. Human beings have been elevated the extinction of 5-20% of the species in many groups of species. All available evidence points to a sixth major extinction event currently underway. Previous five mass extinction events were due to planetary change, natural disasters and biological competition. They have eliminated between 35-96% of all species on earth. The current massive wave of biological extinction is mainly due to human activities.
In the year 2006, large numbers of earth’s species are formally classified as rare or endangered or threatened. About 40% of the 40,177 species assessed using the IUCN Red List Criteria are now listed as threatened species with extinction – a total of 16,119 species. Some 10-30% of the mammal, bird and amphibian species are currently threatened with extinction, all due to human actions. Climate change from carbon dioxide emissions accelerate the demise of many forms of life.

Global loss of biodiversity

Of the approximately 265,000 plant species in the world, more than 60,000 are at risk of extinction. About 6000 plants are known to be used in agriculture, forestry and medicine, while only 150 species are used for intensive cultivation (about 20 species producing 90% of the world’s food)Some studies show that about one-eighth of known plant species is threatened with extinction. About 12.5 % of the world’s plant species to become critically rare. Three-fourths of the world’s bird species are declining in population or threatened with extinction. About 27% of the world’s 330 parrot species are in danger of extinction. Amphibians (frogs, salamanders and related species) declining worldwide. About 20% of all reptiles and a third of the world’s 266 known species of turtles are threatened with extinction. About one-third of all fishes and 90% of all large fishes have disappeared from the world’s oceans. Every year between 17,000 and 100,000 species vanish from our planet. Some people say that up to one-fifths of all living species could disappear within 30 years.

Global loss of ecosystems

The ecosystems of the world are maintained by their biodiversity.  Healthy ecosystems support high biodiversity. Every ecosystem can be characterized by its own species composition. Ecosystems differ in their physical structure, temperature, water availability, food types and richness and complexity of biological communities including the number of niches, trophic levels and ecological processes. These differences make certain ecosystems habitable to some species but not to others and enable a great diversity of species to exist across the globe. The habitat heterogeneity hypothesis states that an increase in habitat heterogeneity leads to an increase in species diversity. The increase in the number of habitats leads to an increase in species diversity in a landscape.  Of all marine habitats, the coastal waters are under greatest pressure. Ninety percent of the world’s fish catch (measured by weight) depend on coastal habitats for at least part of their life cycles.Coral reefs, which rival rain forests in diversity, are being destroyed through siltation, coral mining and pollution. Mangroves, which line one quarter of tropical coastal lines, are being cut down for lumbar, fuel wood and to build aquaculture ponds. Estuaries and wetlands, important sites for migratory species, are threatened in many areas by coastal development. Deeper waters, which are rich in diversity, are threatened by the disposal of toxic chemicals.  Global ocean primary production has declined more than 6%. One fourths of marine fish stocks are currently overexploited or significantly depleted. Tropical rain forests are shrinking by 11 million hectares per year. About 31 million hectares forest cover in industrial countries has been changes apparently by air pollution and acid rain. In many parts of the world, logging, grazing and mining are the major threats to endanger forest ecosystems. An estimated 26 billion tons of top soil are lost in excess of new soil formation annually. Some 6 million hectares of new desert are formed annually by land mismanagement. Thousands of lakes in the industrial towns are now biologically dead, thousands more are dying. Underground water tables are falling as demand for water rises above aquifer recharge rates. Fresh water systems tend to be the first habitat to experience a  huge biodiversity loss due to closer contact with human beings. The biodiversity of freshwater lakes, streams, rivers and wetlands may be the most threatened ecosystems on earth. Fully one fifth of the world’s freshwater fishes are either endangered or extinct.

Root causes of biodiversity loss

The Global Biodiversity Strategy (1992) has identified several of the root causes of biodiversity loss.
Population bomb (Paul Ehrlich) – the world’s population has more than tripled in the 20th century and continued growth is expected over the next 50 years especially in the developing countries. As the number of people increases, crowding generates pollution, destroys more habitats and uses up additional natural resources. In addition human beings have the habit of controlling the nature.
Over exploitation and mass consumption of natural resources – population growth and increasing resource consumption affect biodiversity in two ways: they create pressure to convert wildlife habitats into agricultural and urban land and they produce wastes that pollute habitat and poison wildlife.
Ignorance of people about species and ecosystems – most people are not aware of the ecological and economic value of species and the ‘ecological services’ they provide.
Poorly conceived policies – government policies designed to encourage some sectors such as agriculture or forestry can have the side effect of destroying biodiversity.
Global trading systems -  in developing countries which rely heavily on agricultural commodities for export earnings those pressures have pushed farmers toward large scale plantations  growing a relatively narrow range of crops that are in demand (for e.g., coffee, cocoa and bananas) on world markets.
Inequity of resource distribution – globally, there are inequities between richer countries with the technological and financial capacity to develop and exploit natural resources and the poorer countries without such capacity and technology. The environmental impact person varies greatly among and within countries, largely depending on the nature and degree of industrialization.
Failure to account for the value of biodiversity – markets tend to undervalue biodiversity, thereby promoting (directly or indirectly) its depletion. Ironically biodiversity produces and supports immense benefits to society, but it is totally ignored in national economic accounts because it is difficult to value. When market undervalues biodiversity, policies and subsidies may encourage sustainable or destructive activities.

Significance of biodiversity loss

Biodiversity is an extremely important as well as a fundamental component of life on earth. It creates and maintains ecological systems. It is important to the global economy and is essential for food security. It safeguards human health. Without vegetation or organisms, landscapes would be virtually indistinguishable from one another. Biodiversity creates complex environments that could never be reproduced by human beings. The loss of species diversity is unique among other anthropogenic changes because it is irreversible. The value of biodiversity is immeasurable and thus must be protected. Biodiversity is an important concern of scientists, environmental activists, and society as whole and even politicians. Conservation of biodiversity requires communication and cooperation between all of these parties.

Global initiatives on biodiversity conservation

The World Conservation Union, World Resources Institute and United Nations Environment Programme are the three important agencies, whose mandates center on the conservation of the world’s biodiversity. They have developed the ‘Global Biodiversity Strategy’, an international programme to help to protect biodiversity. The broad objectives are to: 1) preserve biodiversity; 2) maintain earth’s ecological processes and life- support systems and 3) ensure that natural resources will be sustainably used by humans.

“Biodiversity is the strength of the web of life, binding together all living things. It is greatest expression of the truth that diversity holds the key to life. It is also one of the most important and threatened assets left to mankind. The protection, promotion and wise utilization of biodiversity may very well form the cornerstone of our future global survival.”     -Marthinus van Schalkwyk (Biodiversity synthesis report).

Thursday, March 27, 2014

Is the marine environment threatened?

Oceans are the largest ecosystem of the planet earth. They are the lifeblood of planet earth. Oceans cover greater than 70% of the earth’s surface. About 70% of the earth’s oxygen is produced by oceanic phytoplankton. Ocean is crucial for the maintenance of oxygen-carbon dioxide balance of the biosphere. About 97% of world’s water resides in oceans. Oceans provide a sixth of the animal protein people eat. They are the essential source new medicines to combat cancer, pain and bacterial diseases. Oceans absorb carbon dioxide from the atmosphere and reduce the impact of climate change. About half of the world’s population lives within the coastal zone. About 80% of non-biological marine pollution comes from land based activities.


Marine pollution is the introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries), resulting in such deleterious effects as; harm to living resources: hazards to human health; hindrance to marine activities including fishing; impairing the quality for use of sea water and reduction of amenities (The Inter-Governmental Oceanographic Commission, -UNESCO).

Causes of coastal marine pollution

The dominant driving factors of marine pollution are population growth, industrialization and urbanization. Marine pollutants include sewage, oil, garbage, nutrients, pesticides, and toxic chemicals, and heavy metals, thermal and radioactive wastes.

Categories of marine pollutants

The wastes can be divided into two major categories such as domestic and industrial wastes. The domestic wastes include municipal sewage, agricultural and urban runoff, garbage, plastic debris and land clearing wastes. Industrial wastes include heavy metals, radioactive nuclides, inorganic chemicals and heated water.

Marine eutrophication/ Nutrient pollution

It is the over-enrichment of nutrients which may of two types: natural eutrophication and anthropogenic eutrophication
Natural eutrophication is the upwelling of nutrient inputs, river-borne nutrients (not polluted). It is a slow process (time scale 10³-10 years) and induces ecosystem adaptations.
Cultural eutrophication results in the disposal of sewage, solid wastes, industrial effluents and agricultural fertilizers. The Mississippi river carries an estimated 1.5 million tons of nitrogen pollution into the Gulf of Mexico each year.This anthropogenic eutrophication add excessive amounts of plant nutrients primarily P,N and C. This leads to excessive algal growth and decay.
Features of Eutrophication- Eutrophication is characterized by high concentration of nutrients, high phytoplankton densities, and frequent incidence of red tides, high densities of herbivores and predators and mass mortalities of near –shore organisms. The oxygen level in bottom waters is depleted by the decomposition of organic matter. Near -bottom anoxia leads to the loss of benthic organisms.

Eutrophication – induced changes

Increased input of nutrients results in deterioration of water quality. There is a large scale incidence of red tides, a bloom of red colored phytoplankton (typically dinoflgellates) or growth of coastal macro algal vegetation. These marine algae produce toxins that are poisonous to vertebrates like birds, mammals and humans. Filter feeders like clams and shellfish strain the algae out of sea water during a bloom. Illnesses caused by toxins are being passed through food chain and cause Ciguatera fish poisoning (CFP), diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP). The water transparency is decreased due to mineral turbidity and cloudy detritus which reduces light penetration in euphotic layers. Hazards to Human health hazards are caused by industrial or domestic effluents with toxic metals, detergents, pesticides, phenols, ammonia, H2S etc. This may also reduce aquaculture opportunities or impairing quality of its products. There is a reduction in species and tropic diversity which may cause loss of fisheries resources. Loss of water clarity, dead animals on shore, foul smells, toxic shell fish etc. damage recreational value.

Garbage and plastics disposal

Solid wastes are generally garbage and rubbish which present the most visible form of pollution (visual pollution). About 14 billion pounds of garbage are dumped into the ocean every year. Disposal such wastes pose a major threat to marine communities. Plastics thrown into the sea can stay there for many years and harm marine life. A huge number of marine animals die every year from either ingesting or become entangled in plastic trash. More than 180 species of animals have been documented to ingest plastic debris. Seals and sea lions starve after being entangled by disposed nets. Plastic debris kills 100,000 marine mammals and 2 million sea birds per year.

Negative impact of sewage disposal

Sewage disposal cause turbidity of sea water which depresses phytoplankton production. Sedimentation changes benthic environment and induces hypoxia/anoxia (oxygen demand). This oxygen depletion pollution causes loss of biodiversity, changes in the species composition and dominance which leads to species – poor communities. This pollution related makes the habitat unsuitable for benthic organisms of commercial importance. The contamination of sewage leads to offensive odor,bacterial and viral enteric infections. The consumption of contaminated shell fish leads to human health problems.

Pesticide contamination

Pesticides are chemicals used to kill insect pest, weeds and pathogenic microorganisms that might damage crops. Pesticides can enter the sea water through urban and agricultural land runoff (nonpoint source). Pesticide contamination of sea water results in fish kills, reduction of growth and impairment of reproduction fish and invertebrates. Poisoning of DDT induces egg-shell thinning in marine birds, which drastically reduces their population. Poisoning in humans leads to potential toxic effects, neurological disorders and reproductive and birth defects.

Contamination of petroleum hydrocarbons

Oil spills cause huge damage to the marine environment but are responsible for about 12% of the oil entering the seas each year. Tankers and cargo ships discharge petroleum hydrocarbons either deliberately or accidentally. In 1992, more than 4 million tons of oil was released into the world’s oceans. In 1992, there are 611 incidents of oil pollution in UK coastal waters alone. Many of the major oil spillages during the last 20 years have been caused or made worse by human error. Exposure to oils causes smothering and clogging of organs which interferes with feeding, reproduction, growth and behavior. The tainting sea foods lead to un-marketability. Human health effects include cancer risks.

Contamination of heavy metals

Heavy metals are of great concern because they enter animal and human food chain. Most dangerous metals include mercury, cadmium, lead and copper. Copper is dangerous to marine organisms and has been used in marine antifouling paints. Exposure to heavy metals causes mortality of juvenile stages of marine organisms and toxicity to phytoplankton, invertebrates and fish. Heavy metal exposure may affect morphology, physiology and behavior of marine organisms. Heavy metals cause potential mammalian toxicity and skeletal, muscular and neurological problems.

Contamination of radio nuclides

The term “nuclear waste” is generally used to represent all radioactive waste materials regardless of their origin, material form or radioactivity levels. Exposure to radioactive waste cause both somatic and genetic effects. The somatic effects include acute lethality and skin allergies. The genetic effects are mutations and cancers.

Impact of Global Climate Change

Climate change damages plant and animal physiology, abundances, and distributions. It has altered bio-productivity and species interactions. It may decreased or increased precipitation, thereby altering coastal and estuarine ecosystems. Species that are unable to migrate or compete with other species for resources may faced extinction. Changes in precipitation and sea-level rise affected the water balance of coastal ecosystems. The increases in precipitation and runoff may caused the risk of coastal flooding. Climate change affected the structure (e.g., plant and animal composition) and function (e.g., plant and animal production, nutrient cycling) of estuarine and marine systems.

Critical coastal ecosystems

Wetlands, estuaries, and coral reefs are particularly vulnerable to climate change. Such ecosystems are among the most biologically productive environments in the world. Climate change may degrade these valuable ecosystems, threatening their ecological sustainability and the flow of goods and services they provide to human populations

Conservation of global oceanic environment

The ocean is international property or global commons. No nation has any right, moral or legal to pollute any part of it, including territorial waters. Habitat protection is the most serious need for coastal and marine biodiversity. The presence of toxic wastes in offshore waters must be curtailed by stricter laws. There should be an optimum exploitation of living and non-living resources. There is a need for co-ordinated, centralized and highly sophisticated research programmes to identify various pathways by which pollutants enter the ocean and to analyze the behavior of individual pollutants. The damaged habitats are restored by re-vegetation of mash grasses, mangroves and sea-grasses. International and national bodies should be initiated to monitor the growth of marine pollution.

Wednesday, March 26, 2014

Developing reasoning skills

The ability to reason is the fundamental characteristic of human beingsReasoning is a form of thinking or the highest activity stage of thinking. John Dewey described reasoning as ‘speculative thinking’ or ‘reflective thinking.’ Reasoning refers to the act or process of drawing conclusion or inferences from information(observations, facts, guesses or assumptions) following principles or rules of logic.Reasoning is the process by which we advance from what we know already to new knowledge and understanding. Reasoning skills involve clarifying, meaning, explaining, analyzing, opinion forming, decision making, interpreting and giving reasons for conclusions.Though reasoning, problem solving and decision making are different, but they represent overlapping aspects of human intelligence.

Theories of reasoning

Reasoning processes revolves around two theories, mental rules theory and mental model theory. According to mental rules theory, the basic processes involved in deductive reasoning problems are (a) encoding the premises into representations stored in working memory, (b) applying abstract, rule-based schemas to these representations to derive a conclusion and (c) applying other rules to check the contents of working memory for incompatibilities. The mental models theory of deductive reasoning posits that the individual first transforms the premises of an argument into another representation (i.e., mental model) that is consistent with the premises.

Elements of reasoning

1.  All reasoning involves thinking.
2. All reasoning has a purpose.
3. All reasoning is an attempt to figure something out, to settle some question, to solve some problem.
4. All reasoning is based on assumptions.
5. All reasoning is done from some point of view.
6. All reasoning is based on data, information and evidence.
7. All reasoning is expressed through, and shaped by concepts and ideas.
8. All reasoning contains inferences or interpretations by which we draw conclusions and give meanings to data.
9. All reasoning leads somewhere or has implications and consequences.

Kinds of reasoning

Tacit (intuitive) reasoning is the reasoning without conscious intervention and outside awareness. It depends on the network of ideas and associations in the memory. Intentional (explicit) reasoning is the strategic or rule – based reasoning. It requires effort and accumulation of varied experiences. Thus reasoning involves both conscious (and explicit) and unconscious (or tacit) processes. Reasoning depends importantly on knowledge. Everyday reasoning depends on the efficacy of past reasoning processes (stored as knowledge) as well as the efficacy of present reasoning processes.

Mental processes in reasoning (Steinberg, 1986)

1.       Selective encoding refers to the process of distinguishing relevant from irrelevant information.
2.       Selective comparison means retrieving and then comparing only a subset of potentially relevant information about the associated concepts from long-term memory.
3.       Strategic combination is the orderly, strategic or planful combination of information in working memory. It requires deductive reasoning (formulating logical arguments or a mathematical proof).

Categories of reasoning

Analytical reasoning includes classifying, organizing and evaluating information. In some cases analysis is based on deduction. Deduction works by elimination, being a process of dividing the appropriate from the inappropriate items of information.
Spatial reasoning is the deduction of differences, likenesses and parallels in shape and size. It is an  ability to visualize, compare and transform objects.
Numerical or mathematical reasoning is an ability to apply quantitative methods and using models (real-world situations) to make predictions and informed decisions.
Scientific reasoning involves deduction (‘drawing out’ conclusion from an assumed generalization) and induction (drawing conclusions from observations) as well as experiments and statistical analysis.
Verbal reasoning is the ability to understand and communicate using language or ability to analyse information and solve problems using language based reasoning.
Logical reasoning is the ability to find inherent relationship among facts – provided there is one – so that the facts yield ideas or principles. Logic is the science of valid reasoning. Aristotle was the founder of the science of logic.

Development of reasoning ability  

Logical method is studying the logical connections of premises and conclusions and the practical connections of causes and effects.
Scientific method consists of systematic observation, measurement and experiment. It is an ongoing cycle of formulating, testing and modifying hypothesis. Hypothesisàexperimentationàrefines the ideaàexperimentationàfinal statement.
Systems method applies a systems or holistic perspective by taking all aspects of the situation  into account and by concentrating on the interactions between the different elements (systems and components).

Aspects of reasoning

Inductive – begins with a small fact, building upon that to a major conclusion. This is a process of reasoning from parts to the whole from examples to generalization.
Deductive –starts with a major point and gradually defends that point down to the smallest fact. This type of reasoning moves from the whole to its parts, from generalization to underlying concepts and examples.
Chronological – organized according to time, often earliest to most recent.
Spatial – uses diagrams, maps or pictures to guide  the direction of a oral presentation.
Logical – follows some sequence of events or steps in an evolutionary manner.
Topical – presents several content areas with no apparent connection.

Basic processes of reasoning

Storage and retrieval skills enable the thinker to transfer information to and from long-term memory. Visual imagery is used for the information to be remembered. Mnemonic strategies are also examples of storage and retrieval skills.
Matching skills enable a thinker to determine how the incoming information is similar to or different from information already stored in long-term memory. There are 5 types of matching skills.

  1. Categorization enables thinkers to classify objects or ideas as belonging to a group and having the characteristics of that group. This has been referred to as chunking.
  2. Extrapolation enables a thinker to match the pattern of information from one area to that found in another area.
  3. Analogy involves seeing the similarities among essentially different objects or ideas and using the existing knowledge about the first set of objects or ideas to understand others.
  4. Evaluation of logic is the process of comparing the structure of information with an internalized system of logic to see if the information is valid or true.
  5. Evaluation of value is the process of matching information to an internalized value system and analyzing the logic of that system.

Analysis and synthesis

Analysis is taking apart and examining the pieces of collected data. In other words analysis means understanding the whole of something by breaking it down into its parts. It can be contrastive or comparative analysis. In contrastive analysis, you break something down into parts in order to understand something that is different from or that contrasts with the original object of analysis. In comparative analysis, you break something down into parts in order to understand something that is similar with the original object of analysis.
Synthesis is pulling the pieces together again and simplifying and organizing them in a meaningful way. Synthesis is just the reverse of analysis. Synthesis proceeds by induction. It is essentially a process of organizing and adding together concepts and other intellectual data in order to reach new knowledge.

Quotes for reflection

“Man is a reasoning rather than a reasonable animal.”  -Alexander Hamilton.

“The energy of the mind is the essence of life.”  - Aristotle.

“Give a man a truth and he will think for a day.

  Teach a man to reason and he will think for a lifetime.”

Tuesday, March 25, 2014

Why is the earth warming? Carbon footprints and impacts

Humans have extensively altered the global environment. Exponential growth in population and resource use has drastically changed the face of our home planet. Every year more forests, grasslands and wetlands disappear and the deserts grow larger. Burning fossil fuels, cutting down and burning forests raise the concentration of carbon dioxide and other heat trapping gases in the lower atmosphere. Fossil fuel consumption and deforestation have increased the concentration of atmospheric carbon dioxide by 30%. We have more than doubled the concentration of methane and increased the concentration of greenhouse gases (GHGs) that contribute to climate warming. Within next 40-50 years climate is warm enough to disrupt agricultural productivity, alter water distribution and drive countless species to extinction. Every hour, we drive as many as 4 wild species to extinction.

Global climate machine

Greenhouse gases (GHGs) have been essential to the survival life on planet earth. These atmospheric gases envelop the earth. The gases in the atmosphere are held in place by gravity. The gaseous envelope regulates Earth’s temperature. They trap heat and cause the earth to warm. This is called natural greenhouse effect. To make sure that the Earth's temperature remains constant, the balance of these gases in the atmosphere must not be upset.

Enhanced/amplified greenhouse effect

Human activities alter the proportion of GHGs in the atmosphere. The burning of fossil fuels - coal, oil and natural gas – releases more carbon dioxide into the atmosphere. Since 1990, yearly emissions of greenhouse gases have gone up by about 6 billion metric tons (6.61 billion tons) worldwide, an increase of more than 20 percent. The addition of  more GHGs induces more heat trapping by the atmosphere which results in enhanced greenhouse effect. The average surface temperature of the Earth has increased by 0.8 degrees Celsius in the last 130 years, since 1975. It will rise from 1.5 degrees C to 4.5 degrees C by 2060.

Mechanism of greenhouse warming

The energy from the sun that reaches the top of the earth’s atmosphere consists mainly of infrared (IR) and visible light, with a small amount of ultraviolet light (UV). Of  these solar radiation, about 50% is absorbed by the surface of the earth, 20% is absorbed by water droplets in the air and GHGs. The remaining incoming sunlight is reflected back into space. The energy emitted by the earth must equal the energy absorbed for the temperature to remain constant. Currently, the planet is absorbing more than it emits.  Water vapor acts as an amplifier of warming.

Carbon dioxide: the principal climate altering gas

Generally single element gas molecules like oxygen and nitrogen are transparent to heat and they constitute about 99 per cent of our atmosphere: 78 per cent nitrogen and 21 per cent oxygen. They do not really affect the climate regulation on the planet. The six trace gases that are blamed for global warming make up only 1 per cent of gases in the atmosphere. The gases created mainly by human activities are: carbon dioxide, methane, nitrous oxide, sulphur hexafluoride, hydrofluorocarbons and perfluorocarbons. The polyatomic  gases such as water vapor, methane and carbon dioxide trap heat in the atmosphere much like glass in a greenhouse traps heat. The atmospheric carbon dioxide is the principal climate –altering gas. An individual molecule of CO2 has a short residence time in the atmosphere. The warming potential of CO2 has very little to do with the residence time of CO2. What really governs the warming potential is how long the extra CO2 remains in the atmosphere. Around 20% of carbon dioxide which is emitted due to human activities can remain in the atmosphere for many thousands of years.
Global CO2 Level à1750: 280ppm à1958: 315PPM à2002: 372PPM à2008:384PPM à2100:650-700PPM
China tops the list of global cumulative energy-related CO2 emitting countries. In 2008, china produced 23.5 % of world CO2 emissions while the USA 18.27%, EU 13.98%, India 5.83%, Russia 5.72%, and Japan 4.04%.

Sources of heat – trapping gases (GHGs)

Non-greenhouse gases are nitrogen,N2, oxygen,O2 and argon, Ar. Greenhouse gases  (GHGs) include carbon dioxide (CO2), nitrous oxide (NO2), methane (CH4), chlorofluorocarbons (CFCs)- Freon (a refrigerant), halons ( fire extinguishers) and water vapor -clouds reradiate heat back to Earth. The heat retention capacity of methane is 25 times greater than carbon dioxide. Nitrous oxide is about 200 times more than carbon dioxide. Water vapor and ozone occur naturally in the atmosphere. Carbon dioxide produced also naturally when people and animals breathe. Increased amounts are produced when human beings burn more fossil fuels and wood.Volcanoes also produces this gas. Methane comes from cattle as they digest their food and from the paddy fields, sediments, swamps and landfills. Nitrous oxide is produced from fertilizer use and decomposition of animal wastes.

Global warming

Global warming is a function of increase in carbon dioxide level, increase in greenhouse effect and increase in global temperature. Global warming is caused by the emission of greenhouse gases. 72% of the emitted greenhouse gases are made up of carbon dioxide (CO2). Carbon dioxide emissions therefore are the main cause of global warming. CO2 is caused by burning fuels like oil, natural gas, diesel, petrol and ethanol. Emissions of CO2 have been increasing at a rate of approximately 3% yearly for the past 50 years. Once it is released into the atmosphere where it remains for 100 to 200 years. A warming of 2ºC corresponds to an amount of 250 ppm carbon dioxide concentration in environment. In February 2007, the United Nations Intergovernmental Panel on Climate Change (IPCC) released a report that said global warming was “very likely” – meaning an at least 90 per cent certainty – caused by human activity.

History of global warming

In 1824, French mathematician and scientist Lean Baptiste Fourier described earth as a giant greenhouse with an atmosphere that traps heat from the sun, making life on earth possible. In 1860, John Tyndall, a British scientist postulated that a reduction in the amount of carbon dioxide in the atmosphere decrease the greenhouse effect. After 36 years, Svante Arrhenius, a Swedish chemist hypothesized that doubling the concentration of carbon dioxide would increase the temperature by 5-60C.  In 1938, G.S. Callender, a British meteorologist had gathered information from 200 weather stations around the world and demonstrated that the average surface temperatures had increased between the 1880s and the 1930s.

Ecological effects

Global warming could lead to natural disasters, large-scale food and water shortages and devastating outcomes for wildlife. According to the Intergovernmental Panel on Climate Change, the sea level could rise between 7 and 23 inches (17.8 and 58.4 centimeters) by the end of the century. Rise of just 4 inches (0.9 meters) of sea level would submerge much of the world’s population living near coastal areas. According to research published in Nature, by 2050, rising temperatures could lead to the extinction of more than a million species.
More than a million species face extinction from disappearing habitat, changing ecosystems and acid rain. Scientists have come up with the firmest evidence so far that global warming will significantly increase the intensity of the most extreme storms worldwide. The maximum wind speeds of the strongest tropical cyclones have increased significantly since 1981, according to research published in Nature. Global warming causes more violent swings between floods and droughts. Climate change is expected to have the most severe impact on water supplies. Shortages in future are likely to threaten food production, reduce sanitation, and hinder economic development and damage ecosystems.
 The International Panel on Climate Change estimates that the sea level will rise between 0.6 and 2 feet in the next century. This poses a great threat to coastal wetland ecosystems. Wetlands are a thriving habitat for thousands of species and also serve to protect nearby areas from flooding. The EPA has estimated that a two foot rise in sea level would result in the loss of 17-43 percent of wetlands in the United States. Scientists believe that global warming will cause an increase in global hunger since plant crops become inefficient to produce. Studies show a rise in wild fires due to the slight increase in temperature. Wildfires have the potential to demolish dozens of square miles of both agricultural land and natural habitat of thousands of species of wildlife.

Biological effects

Global warming is currently a critical problem for many species of plants and animals around the globe. Global warming directly affects the metabolic and developmental rates in many animals and processes such as photosynthesis, respiration and growth in plants. Plants and animals are adapted to a specific climate, and can only survive in that particular climate. As the temperature changes, animals must migrate to adapt. The migration of species to more suitable climates upsets the balance of interdependence among species in their ecosystems. Global warming increases the invasion of opportunistic, weedy and/or highly mobile animal species.

Human health effects

A major health risk is the migration of disease carrying insects throughout the world. Mosquitoes carry many major health science related problems like malaria. Extreme high air temperatures contribute directly to deaths from cardiovascular and respiratory disease, particularly among elderly people. The heat waves of summer 2003 in Europe for example, more than 70 000 excess deaths were recorded. High temperatures also raise the levels of ozone and other pollutants in the air that exacerbate cardiovascular and respiratory disease. Urban air pollution causes about 1.2 million deaths every year. Pollen and other aeroallergen levels are also higher in extreme heat. These can trigger asthma, which affects around 300 million people.

Carbon Footprint (CF)

The term describes the total set of greenhouse gas emissions caused by one individual. A measure of the amount of carbon dioxide emitted through fossil fuel combustion. The carbon footprint has become a popular tool to estimate GHG emissions related to human activities (Moss et al 2008,Wiedmann 2009). Carbon footprint (CF) – also named Carbon profile - is the overall amount of carbon dioxide (CO2) and other greenhouse gas (GHG) emissions associated with a product.). An average Carbon footprint of a British citizen is about 10 tonnes of CO2. An average Carbon footprint of an Indian citizen is round about 1.5 tonnes of CO2. The primary footprint is a measure of our direct emissions of carbon dioxide e.g.the burning of fossil fuels for domestic energy consumption and transportation. The secondary footprint is a measure of the indirect carbon dioxide emissions from the whole lifecycle of the products.

Types of  carbon emissions

 Different types of carbon emissions are designated as “colors of carbon
  1.   Brown carbon – industrial emissions of GHGs.
  2.  Black carbon – carbon from incomplete combustion of fossil fuels.
  3.  Green carbon – carbon stored in terrestrial ecosystems-e.g. plants, soils, wetlands grazing lands.
  4. ·Blue carbon – carbon stored in ocean ecosystems- e.g. mangroves, marshes, sea grasses, coral reefs, macro-algae.

The Kyoto Protocol

The Kyoto protocol (Kyoto, Japan) to the United Nations Framework Convention on Climate Change (UNFCCC) is an international treaty that sets binding obligations on industrialized countries to reduce emissions of greenhouse gases(GHGs). The protocol was adopted by parties to the UNFCCC in 1997 and entered into force in 2005.Six greenhouse gases are regulated by the Kyoto Protocol, as they are emitted in significant quantities by human activities and contribute to climate change. The six regulated gases are Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur hexafluoride (SF6).

Monday, March 24, 2014

Is the global climate changing? fingerprint variables and effects

 Climate change refers to  long - term changes in the earth's weather, including changes in temperature, wind patterns and rainfall, especially the increase in the temperature of the earth's atmosphere that is caused by the increase of particular gases, especially carbon dioxide. Global climate is determined by the energy transfer from the sun at and near the earth’s surface. This energy transfer is influenced by dynamic processes such as cloud cover and the earth’s rotation and static conditions such as the position of mountain ranges and oceans. The biosphere is primarily responsible for modulating the climate and the environment of the earth to its benefit.  The earth’s climate has warmed by approximately 0.60C over the past 100 years. The small changes in the average temperature can lead to large shifts in climate and weather. Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use. Climate change is shown in the melting of ice-sheets and snow, warming of oceans and rising in sea levels.

Factors influencing the earth’s climate

  • Variations in the solar radiations
  • Changes in the greenhouse gas concentrations 
  • Changes in ocean circulation

    Fingerprint variables  of climate change

Fingerprints are changes that show a certain pattern that is unique to a specific climate-change driver. Finger printing assumes that each individual influence on climate has a unique signature in climate records. Fingerprint method compares the pattern of temperature trends calculated from greenhouse models with the pattern observed in the atmosphere. The climate fingerprints are estimated with computer models.

Fingerprint variables

The amount of water vapour in the atmosphere is the human fingerprint. The primary driver of atmospheric moistening is the increase in carbon dioxide caused by the burning of fossil fuels (coal, oil and natural gas).
Global mean surface temperature is a fingerprint variable used to predict enhanced greenhouse effect.
Tropopause height is an integrated fingerprint variable of human induced climate change. It reflects global scale changes in the temperature structure of the atmosphere. The Tropopause is the boundary between the turbulently mixed troposphere and the more stable stratosphere. It lies roughly 10 miles above the earth’s surface at the equator and 5 miles above the poles. The location of the tropopause is sensitive to changes in vertical profiles of atmospheric temperature. Human-induced changes in ozone and GHGs are the primary drivers of changes in the height of the tropopause.  
The heat penetration into the ocean is another fingerprint variable of climate change. The six oceans that circle the globe have been warming as a result of enhanced greenhouse warming. The heat penetration with depth varies from ocean to ocean which indicates of anthropogenic influence of climate change.

Evidences of climate change (IPCC report 2007)

The ocean temperature has risen about 0.50C in the last 40 years. The Arctic freshwater ice sheet has melted around an area of 20000 km2 from 1965 to 1995. In the last 100 years, the global average sea level risen about 10 to 25 cm. The earth experienced 11 warmest of the last 12 years. In the past 100 years, the global surface temperature has risen about 0.70C and average annual temperature in the Arctic to 10C. According to the IPCC report the main characteristic of climate change is an increase in average global temperature.

Biological effects of climate change

Climate directly affects the functions of individual organisms (e.g., growth, behaviour), modifies populations (e.g., age structure and size). Climate change also affects ecosystem structure and function (e.g., decomposition, nutrient cycling, water flows, species composition and species interaction) and the distribution of ecosystems within landscape. Warming of climate could force species to migrate to higher latitudes or higher elevations where temperatures are more conducive to their survival. 

Ecological effects of climate change

The ecological impacts of climate change are diverse altering plant phenology and growth, carbon and nutrient cycling, as well as biodiversity and extinction risk. Climate changes cause food web disruptions in the polar bears and mismatches in the timing of migration, breeding and food availability. A warming of the ocean results in acidification and mass mortality of coral reefs (Schneider et al., 2007). Increased global temperature will cause more heat waves, heavy rainstorms and frequent wildfires. Climate change has complex effects on water supply and demand. Warmer temperatures cause more precipitation, higher evaporation rates and long-lasting droughts in some places.

Human health effects of climate change

Warmer climates cause more illnesses and injury from heat waves and fires and more food- and water- borne diseases. Climate change may affect allergies and respiratory health. Warmer temperatures from climate change will increase the frequency of unhealthy levels of ground- level ozone which can damage lung tissue, reduce lung function and inflame airways. Change in climate may enhance the spread of some diseases.