Future carbon footprint reduction for power generation – Ways to mitigate emission:

Future carbon footprint reduction for power generation – Ways to mitigate emission:

The greatest potential for carbon footprint reduction is in conventional fossil fuelled electricity generation, using improved combustion technologies, carbon capture and storage and co-firing with biomass. We tried to examine most the technologies available to know the potential to reduce their carbon footprint.

a. Fossil fuel generation – future carbon footprint - Technology improvements could increase the energy efficiency of existing coal fired plants from current levels of ~35% (where only 35% of the fuel energy is converted into electricity) to over 50% (by using super-critical thermal power plant). Improvements in energy efficiency can halve life cycle carbon emissions in both coal and gas fired plants. Carbon capture and storage (CCS) could potentially avoid 90% of CO2 emissions to the atmosphere in the future.

b. Co-firing fossil fuels and biomass - Co-firing biomass along side fossil fuels in existing power plants can also significantly lower their carbon emissions, because the fossil fuels are replaced by ‘carbon neutral’ biomass.

c. Future carbon footprint reductions in all technologies - Carbon footprints could be further reduced in all electricity generation technologies if the manufacturing phase and other phases of their life cycles were fuelled by low carbon energy sources. For example, if steel for wind turbines were made using electricity generated by wind, solar or nuclear plants. Using fewer raw materials would also lower life cycle CO2 emissions, especially in emerging technologies such as marine and PV. New semi-conducting materials (organic cells and nano-rods), are being researched for PV, as alternatives to energy and resource intensive silicon.

d. Future nuclear footprint & global uranium resources - Some analysts are concerned that the future carbon footprint of nuclear power could increase if lower grade uranium ore is used, as it would require more energy to extract and refine to a level usable in a nuclear reactor. Point is to be noted: if lower grades of uranium are used in the future the footprint of nuclear will increase, but only to a level comparable with other ‘low carbon’ technologies and will not be as large as the footprints of fossil fuelled systems.

Overview of future carbon footprint reduction –

(1) All electricity generation technologies emit CO2 at some point during their life cycle. None of these technologies are entirely ‘carbon free’.

(2) Life cycle inventory analysis is used to measure the amount of CO2 emitted by each technology.

(3) Fossil fuelled electricity generation has the largest carbon footprint (up to 1,000gCO2eq/kWh). Most emissions arise during plant operation.

(4) ‘Low carbon’ technologies have low life cycle carbon emissions (<100gco2eq/kwh).>

(5) Future carbon footprints can be reduced for all electricity generation plants if high CO2 emission phases are fuelled by low carbon energy sources.

Carbon footprints of power generation using various technologies – Useful for selecting clean technology:

Carbon footprints of power generation using various technologies – Useful for selecting clean technology:

All electricity generation systems have a ‘carbon footprint’, that is, at some points during their construction and operation carbon dioxide (CO2) and other greenhouse gases are emitted to the atmosphere.

To compare the impacts of various different technologies accurately, the total CO2 amounts emitted throughout a system’s life must be calculated. Emissions can be both, direct – arising during operation of the power plant, and indirect – arising during other non-operational phases of the life cycle. Fossil fuelled technologies (coal, oil, gas) have the largest carbon footprints, because they burn these fuels during operation. Non-fossil fuel based technologies such as wind, photovoltaic (solar), hydro, biomass, wave / tidal and nuclear are often referred to as ‘low carbon’ or ‘carbon neutral’ because they do not emit CO2 during their operation. However, they are not ‘carbon free’ forms of generation since CO2 emissions do arise in other phases of their life cycle such as during extraction, construction, maintenance and decommissioning.

A ‘carbon footprint’ is the total amount of CO2 and other greenhouse gases, emitted over the full life cycle of a process or product. It is expressed as grams of CO2 equivalent per kilowatt hour of generation (gCO2eq/kWh), which accounts for the different global warming effects of other greenhouse gases.

Calculating carbon footprints - Carbon footprints are calculated using a method called life cycle assessment (LCA). This method is used to analyze the cumulative environmental impacts of a process or product through all the stages of its life. It takes into account energy inputs and emission outputs throughout the whole production chain from exploration and extraction of raw materials to processing, transport and final use. The LCA method is internationally accredited by ISO 14000 standards.

Carbon footprints:

a. Fossil fuelled technologies - The carbon footprint of fossil fuelled power plants is dominated by emissions during their operation. Indirect emissions during other life cycle phases such as raw material extraction and plant construction are relatively minor.

i) Coal burning power systems have the largest carbon footprint of all the electricity generation systems analyzed here. Conventional coal combustion systems result in emissions of the order of >1,000 gCO2eq/kWh. Lower emissions can be achieved using newer gasification plants (<800gco2eq/kwh),>

ii) Oil accounts for only a very small proportion (about 1%) of the electricity generated in most of the countries. It is primarily used as a back-up fuel to cover peak electricity demand periods. The average carbon footprint of oil-fired electricity generation plants is ~650gCO2eq/kWh.

iii) Current gas powered electricity generation has a carbon footprint around half that of coal (~500gCO2eq/kWh), because gas has a lower carbon content than coal. Like coal fired plants, gas plants could co-fire biomass to reduce carbon emissions in the future.

b. Low carbon technologies - In contrast to fossil fuelled power generation, the common feature of renewable and nuclear energy systems is that emissions of greenhouse gases and other atmospheric pollutants are ‘indirect’, that is, they arise from stages of the life cycle other than power generation.

i) Biomass - Biomass is obtained from organic matter, either directly from dedicated energy crops like short-rotation coppice willow and grasses such as straw, or indirectly from industrial and agricultural by-products such as wood-chips. The use of biomass is generally classed as ‘carbon neutral’ because the CO2 released by burning is equivalent to the CO2 absorbed by the plants during their growth. However, other life cycle energy inputs affect this ‘carbon neutral’ balance, for example emissions arise from fertilizer production, harvesting, drying and transportation.

Biomass fuels are much lower in energy and density than fossil fuels. This means that large quantities of biomass must be grown and harvested to produce enough feedstock for combustion in a power station. Transporting large amounts of feedstock increases life cycle CO2 emissions, so biomass electricity generation is most suited to small-scale local generation facilities,

ii) Photovoltaic (PV) - Photovoltaic (PV), also known as solar cells, are made of crystalline silicon, a semi-conducting material which converts sunlight into electricity. The silicon required for PV modules is extracted from quartz sand at high temperatures. This is the most energy intensive phase of PV module production, accounting for 60% of the total energy requirement. Life cycle CO2 emissions for photovoltaic power systems are currently 58gCO2eq/kWh. However, future reductions in the carbon footprint of PV cells are expected to be achieved in thin film technologies which use thinner layers of silicon, and with the development new semi-conducting materials which are less energy intensive.

iii) Marine technologies (wave and tidal) - There are two types of marine energy devices; wave energy converters and tidal (stream and barrage) devices. Marine based electricity generation is still an emerging technology and is not yet operating on a commercial scale.

iv) Hydro - Hydropower converts the energy from flowing water, via turbines and generators, into electricity. There are two main types of hydroelectric schemes; storage and run-of -river. Storage schemes require dams. In run-of-river schemes, turbines are placed in the natural flow of a river. Once in operation, hydro schemes emit very little CO2, although some methane emissions do arise due to decomposition of flooded vegetation. Storage schemes have a higher footprint, (~10-30gCO2eq/kWh), than run-of-river schemes as they require large amounts of raw materials (steel and concrete) to construct the dam.

v) Wind - Electricity generated from wind energy has one of the lowest carbon footprints. As with other low carbon technologies, nearly all the emissions occur during the manufacturing and construction phases, arising from the production of steel for the tower, concrete for the foundations and epoxy/fibreglass for the rotor blades. Emissions generated during operation of wind turbines arise from routine maintenance inspection trips. This includes use of lubricants and transport. Onshore wind turbines are accessed by vehicle, while offshore turbines are maintained using boats and helicopters. The manufacturing process for both onshore and offshore wind plant is very similar, so life cycle assessment shows that there is little difference between the carbon footprints of onshore (4.64gCO2eq/kWh) versus offshore (5.25gCO2eq/kWh) wind generation.

vi) Nuclear - Nuclear power generation has a relatively small carbon footprints (~5gCO2eq/kWh). Since there is no combustion, (heat is generated by fission of uranium or plutonium), operational CO2 emissions account for <1%>

Carbon footprint – Its reduction means to tackle global warming:

Carbon footprint – Its reduction means to tackle global warming:

A carbon footprint is a ‘measure of the impact of human activities leave on the environment in terms of the amount of green house gases produced, measured in units of carbon dioxide’. It is meant to be useful for individuals and organizations to conceptualize their personal or organizational impact in contributing to global warming.

Reduce your carbon footprint. Whether in coal, oil or gas, carbon is the essential ingredient of all fossil fuels. When these fuels are burned to provide energy, carbon dioxide (CO2), a "greenhouse gas", is released to the Earth’s atmosphere.

As we’ve become more dependent on carbon-based fuels, we’ve seen a rapid increase in the atmospheric concentration of CO2; from around 280 parts per million (ppm) before the industrial revolution, to 370 ppm today. If current trends of fossil fuel use continue the concentration of CO2 is likely to exceed 700 ppm by the end of this century. According to experts, this could lead to global warming of between 1.4 and 5.8°C, which may results in more frequent severe weather conditions and damage to many natural ecosystems. Many believe that it is realistic to promote actions that ensure stabilization of atmospheric CO2 concentrations at around 500-550 ppm. This is a considerable challenge, given that global energy demand is expected to double between 2000 and 2050.

To achieve carbon stabilization, we need to ask ourselves some tough questions:

a. What exactly is our current relationship with carbon?

b. How can we reduce our dependency on carbon emitting technologies and fuels - our carbon footprint?

c. What steps are others taking around the world?
As carbon footprint is the measure of carbon dioxide during the life of a particular industry, ‘life cycle’ concept of carbon footprint is familiar. The life cycle concept of the carbon footprint means that it is all-encompassing and includes all possible causes that give rise to carbon emissions. In other words, all direct (on-site, internal) and indirect emissions (off-site, external, embodied, upstream, downstream etc.) need to be taken into account.

The carbon footprint can be efficiently and effectively reduced by applying the following steps:

(a) Life Cycle Assessment (LCA) to accurately determine the current carbon footprint,

(b) Identification of hot-spots in terms of energy consumption and associated CO₂-emissions,

(c) Optimisation of energy efficiency and, thus, reduction of CO2-emissions and reduction of other GHG emissions contributed from production processes,

(d) Identification of solutions to neutralise the CO2 emissions that cannot be eliminated by energy saving measures,

(e) The last important step includes carbon offsetting; investment in projects that aim at the reducing CO2 emissions, for instance bio-fuels or tree planting activities.

Paper Recycling - Measure for upliftment of our Environment:

Paper Recycling - Helps create something useful out of nothing – Measure for upliftment of our Environment:

Paper is required and used for anything and everything one can think of. With hundreds of final uses, paper satisfies many important human needs. In fact, it is an integral part of everyday life. The technological advances with computers and photocopiers has increased the consumption and wastage of paper.

By using paper carelessly, we contribute to the depleting forest cover, drastic climate change and water pollution. For every ton of paper, the paper industry guzzles up 2.8 tons of dry timber and 24,000 gallons of water, besides electricity and other resources. Pulp and paper industry is a major contributor in terms of air and water pollution.
Recycling of paper not only saves trees and minimises pollution, but also reduces the waste problem by utilizing waste material like used paper, cotton rags and unwanted biomass.

Benefits of paper recycling:

Waste reduction

(a) Paper accounts for a significant amount of municipal waste.

(b) Recycling paper means less waste and disposal problem.

(c) Energy conservation - 60-70% energy savings over virgin paper production.

(d) Resource conservation - Recycled paper uses 55% less water and helps preserve our forests.

(e) Pollution reduction - Recycled paper reduces water pollution by 35%, reduces air pollution by 74%, and eliminates many toxic pollutants.

(f) Livelihood creation - Recycling of waste paper creates more jobs.

REMEMBER

USE OF PAPER LEAVES AN ADVERSE IMPACT ON OUR ENVIRONMENT. OUR GOAL SHOULD BE TO PROMOTE REDUCTION OF CONSUMPTION OF PAPER.

Oil Spill and its adverse effects on marine bio-system and environment:

Oil Spill and its adverse effects on marine bio-system and environment:

Oil is the most common pollutant in the oceans. More than 3 million metric tons of oil contaminates the sea every year. The majority of oil pollution in the oceans comes from land. Runoff and waste from cities, industry, and rivers carries oil into the ocean. Ships cause about a third of the oil pollution in the oceans when they wash out their tanks or dump their bilge water. It is an unfortunate by-product of the storage and transportation of oil and petroleum is the occasional spill. Marine oil spill is a serious consequence of off-shore oil drilling and its oceanic transportation. Spill control firms specialize in the prevention, containment and cleanup of industrial oil spills.

A. The major spills of crude oil and its products in the sea occur during their transport by oil tankers, loading and unloading operations, blowouts, etc. When introduced in the marine environment the oil goes through a variety of transformation involving physical, chemical and biological processes. Physical and chemical processes begin to operate soon after petroleum is spilled on the sea. These include evaporation, spreading, emu1sification, dissolution, sea-air exchange and sedimentation. Chemical oxidation of some of the components of petroleum is also induced in the presence of sunlight. The degraded products of these processes include floating tar lumps, dissolved and particulate hydrocarbon materials in the water column and materials deposited on the bed.

Biological processes though slow also act simultaneously with physical and chemical processes. The important biological processes include degradation by microorganisms to carbon dioxide or organic material in intermediate oxidation stages, uptake by large organisms and subsequent metabolism, storage and discharge.

B. Crude oil and its products are highly complex mixtures. Since the fate of petroleum in the marine environment depends on the composition, a preliminary knowledge of major components and types is necessary for understanding the fate of petroleum when spilled on water. The approximate composition of an average crude oil is considered as :

Normal Type -

Gasoline (C5 - C10 ) 30%; kerosene (C10 -C12 ), 10%; light distillate oil (C12 - C 2 0), 15%; heavy distillate oil (C20 C4 0), 25% residium oil ( >C40), 20%,

By molecular type -

Paraffins (alkanes), 30%; naphthenes (cycloalkanes), 50% aromatics, 15% nitrogen, sulphur and oxygen containing compounds (NSO) 5%.

(a) Spreading - Spreading of crude oil on water is probably the most important process following a spill. Apart from chemical nature of oil, the extent of spreading is affected by wind, waves and currents. Under the influence of hydrostatic and surface forces, the oil spreads quickly attaining average thickness of less than 0.03 mm within 24 h. Once a spill has thinned to the point that surface forces begin to play an important role, the oil layer is no longer continuous and uniform but becomes fragmented by wind and waves into islands where thicker layers of oil are in equilibrium with thinner films rich in surface active compounds.

(b) Evaporation - Evaporation and dissolution are the major processes degrading petroleum crude when spilled on water. The composition of oil, its surface area and physical properties, wind velocity, air and sea temperatures, turbulence and intensity of solar radiation, all affect evaporation rates of hydrocarbons. Evaporation alone will remove about 50% of hydrocarbons in an "average" crude oil on the ocean's surface. Loss of volatile hydrocarbons increases the density and the kinematic viscosity of oil. As more volatile hydrocarbons are lost, the viscosity of the resulting oil increases and this results in breakup of slick into smaller patches. Agitation of these patches enhances incorporation of water due to increased surface area.

(c) Photo-oxidation - The natural sunlight in the presence of oxygen can transform several petroleum hydrocarbons into hydroxy compounds such as aldehydes and ketones and ultimately to low molecular weight carboxylic acids, As the products are hydrophilic, they change the solubility behaviour of the spill.

(d) Dispersion - Dispersion is οil-in-water emulsion resulting from the incorporation of small globules of oil into water column. Oil begins dispersing immediately on contact with water and is most significant during the first ten hours or so.

(e) Dissolution - Dissolution is another physical process in which the low molecular weight hydrocarbons as well as polar non-hydrocarbon compounds are partially lost from the oil to the water column.

(f) Degradation – Bio-degradative processes influencing fate of petroleum in aquatic environment include microbial degradation, ingestion by zooplankton, uptake by aquatic invertebrates and vertebrates as well as bio-turbation. Microorganisms capable of oxidising petroleum hydrocarbons and related compounds are widespread in nature. The rate of microbial degradation varies with the chemical complexity of the crude, the microbial populations and many of the environmental conditions.

C. Effects of petroleum crude on marine bio-system: The biological effects of oil include the possibility of

(a) Hazards to man through eating contaminated seafoods,

(b) Decrease of fisheries resources or damage to wild life such as sea birds and marine mammals,

(c) Decrease of aesthetic values due to unsighty slicks or oiled beaches,

(d) Modification of marine ecosystems by elimination of species with an initial decrease in diversity and productivity and

(e) Modification of habitats, delaying or preventing re-colonization.

When an oil spill occurs, many factors determine whether the spill will cause heavy, long lasting biological damage, comparatively little or no damage or some intermediate degree of damage. Thus for instance, if a spill occurs in a small confined area so that the oil is unable to escape, damage will be greater for a given volume and type of oil spilled than if the same volume was released in a relatively open area.

In the open sea the possible impact on biota can be on phytoplankton, zooplankton, benthos, fishery, birds, mammals, etc. whereas in coastal waters the impacts will also be on inter-tidal fauna, aquaculture, seaweeds and mangroves.

D. Oil Spill Control - Oil spills can occur when there is a problem with an oil well, when a pipeline ruptures or leaks or when there is a transportation accident. Since conditions are different with each spill, different methods of spill control may be used.

Some of the tools used to control oil in a spill include booms, which are floating barriers used to clean oil from the surface of water and to prevent slicks from spreading, skimmers which use pumps or vacuums to remove oil as it floats on water and sorbents which absorb oil when they are placed in a spill area.

Sometimes chemicals called dispersants are used to break down oil and move it from the top of the water. Moving the oil in this way keeps it from animals that live at the surface of the water and allows it to eventually be consumed by bacteria.

A process called bioremediation may be used to accelerate the process of biodegradation of the oil after a spill. In this process, bacteria or other microbes are introduced to the environment to help oxidize the oil. Unfortunately, this process can work slowly and is not very useful for large spills.

Occasionally the slick caused by a spill is removed through a controlled burn. Burning only works under certain wind and weather conditions.

Oil spill control on land is often conducted manually. Scooping, cleansing and scraping of the rocks and sand is performed until the oil has been removed.

Adverse Impacts of Road Traffic exhaust on Human Health and Mitigation measures:

Adverse Impacts of Road Traffic exhaust on Human Health and Mitigation measures:

Automotive vehicle engines produce a number of air pollutants that pose risks to human health. Road vehicles such as cars, buses and trucks are a source of air pollution. When their engines burn fuels (gasoline or diesel), they produce large amounts of chemicals that are emitted in engine exhaust. In addition, some of the gasoline used by engines vaporizes into the air without having burned, and this also creates pollution.

A. Recent study shows that those who reside near major highways had worse indoor air pollution than those in more rural settings, with respect to PAHs (polycyclic aromatic hydrocarbons), a class of compounds that contain known cancer-causing toxins.

Although, stringent regulations on engine performance and fuel formulation have brought about a decline in the amount of air pollution produced by individual vehicles, but due to increase in number of vehicles the air pollution level in urban areas have not come down. Automobile exhaust remains a major source of pollution and the pollutants cause local changes in the air quality, which affect the human health adversely.

B. This causes us great concern on health front of public, especially, children who pose risk to various hazards. Children exposed to high levels of air pollution during their initial years of life run a greater risk of developing asthma, pollen allergies, and impaired respiratory function.

Another group of people those are greatly affected due to vehicular exhaust are traffic personnel - men and women. It has also been reported in many countries that, due to high exposure to toxic fumes of vehicular exhaust among traffic personnel, induced impaired reproductive system observed.

C. The following is a summary of the main pollutants produced by road traffic and the way they may affect our health:

Nitrogen oxides: These are created when vehicle engines burn nitrogen that is present in the air and nitrogen compounds found in fossil fuels. Nitrogen oxides can irritate airways, especially your lungs.

Carbon monoxide: This gas is produced by incomplete combustion of gasoline and diesel fuel. All engine exhaust contains a certain amount of carbon monoxide, but the amount will increase if your vehicle engine is poorly maintained. Carbon monoxide decreases the ability of your blood to carry oxygen.

Volatile organic compounds (VOCs): These are a large family of carbon-containing compounds that evaporate easily. Engine exhaust contains a number of different VOCs. Some of them, such as benzene and 1,3-butadiene, are cancer-causing agents, although the risk at current levels in the environment is small.

Fine particulate matter: These tiny particles contain many substances, including metals, acids, carbon, and polycyclic aromatic hydrocarbons. Some of these particles are emitted in vehicle exhaust, while others are formed in the atmosphere through chemical reactions between the various pollutants found in exhaust. Particulates are known to aggravate symptoms in individuals who already suffer from respiratory or cardiovascular diseases.

Ground-level ozone: This is not emitted directly by vehicle engines, but is formed by chemical reactions between nitrogen oxides and VOCs. These reactions are stimulated by sunlight, and this is why concentrations of ground-level ozone are higher during the summer months. Ground-level ozone irritates airways and can trigger reactions in people who have asthma (Ground-level ozone should not be confused with the ozone layer in the stratosphere, which provides protection from the sun's ultraviolet rays.).

The air pollution from road traffic causes two types of effects on health:

Acute Effects: These effects occur rapidly (in a few hours or days) following exposure to high levels of pollutants. In certain cases, air pollution may worsen symptoms for people with existing heart and lung conditions. Scientific research carried out in some countries has shown that the number of deaths and hospitalizations related to respiratory and cardiac conditions increases when the levels of ground-level ozone or fine particulate matter increase.

Chronic Effects: These occur over time following extended exposures (months or years). Scientific studies in Europe have shown that children living in areas with higher traffic density have more respiratory symptoms than other children.

In general, traffic exhaust pollutants are a major source of air pollution especially in urban areas, and are a major source of greenhouse gas emissions as well. Vehicles run on conventional or diesel engines. Although diesel engines are more efficient, they emit more fine particles than conventional engines. According to many, diesel exhaust is responsible for 70 percent of the cancer risk that the average urban population faces from breathing toxic air pollutants.

Potential health effects from being exposed to traffic-exhaust pollutants include respiratory illnesses (including asthma), cardiovascular disease, adverse reproductive outcomes, cancer, and shortening of the life span.

D. We can help to minimize risks by taking steps to reduce traffic-related air pollution. (a) Whenever possible, use public transit, bicycle or walk instead of using your vehicle. (b) Take fuel efficiency into account when you buy a vehicle. (c) Turn off the engine of your car when you stop for more than 10 seconds, unless you are in traffic or at an intersection. (d) Keep your vehicles well maintained. (e) In addition, you can take steps to help minimize your risk of health effects from traffic-related air pollution, such as,

(i) Pay attention to air quality forecasts in your community, and tailor your activities accordingly.

(ii) Avoid or reduce strenuous outdoor activities when air pollution levels are high, especially in the afternoon during summer months when ground-level ozone reaches its peak.

(iii) Choose indoor activities instead.

(iv) Avoid or reduce exercising near areas where traffic is heavy, especially during rush hour.

(v) If you have a problem of heart or lung, consult health care professional about additional ways to protect your health when air pollution levels are high.

E. Governments can encourage the reduction of vehicular use by:

a. Promoting Voluntary abstention,

b. Increase Public Transit - diversify options and limit access to existing roads.

c. Separate commercial and private traffic to increase efficient use of roads,

d. Stop building car-oriented roads and highways,

e. Replace 30% of the existing roads designed for cars with a variety of transportation options,

f. In cities, build more walking paths, bicycle routes and paths for small electric vehicles, g. Reduce commuting - link residence and business activities by rezoning and rebuilding cities,

h. Reward car-pools and car-sharing plans,

i. Redefine road use by defining access privileges - no longer a right,

j. Road Tolls and increased gasoline and vehicle registration taxes,

k. Base car license fees on fuel consumption in the previous year. Use exponential fee rate increase for high fuel consumption individuals,

l. Provide generous development grants and tax incentives for all non-polluting transportation alternatives.

Mitigation of energy crisis due to high petroleum prices – Renewable energy sources are the answer:

Mitigation of energy crisis due to high petroleum prices – Renewable energy sources are the answer:

A. Harnessing renewable alternative energy of all form is the ideal way to tackle the energy crisis that looms large over the world. The success of energy management lies in the right mix of renewable energy from various sources. In general, there is lack of awareness on sustainable energy in almost all the countries.

B. Because of the present energy crisis experienced by most of the countries due to high petroleum prices, the Government funding for alternative energy is more likely to increase, so too are incentives for oil exploration. In response to mitigate an energy crisis of the present form, it is advisable to follow the principles of green energy by every country. This promotes sustainable living movements among people. The increasing interest in alternate power / fuel research such as fuel cell technology, hydrogen fuel, wind energy, solar energy, geothermal energy, tidal energy and fusion power has to be initiated.

To date, only hydroelectricity and nuclear power have been significant alternatives to fossil fuel. Hydrogen gas is currently produced at a net energy loss from natural gas, which is also experiencing declining production in many countries. The technology for cost effective / cheap generation of hydrogen from water has to be developed fast, so that hydrogen can be utilized as proven energy source / fuel. In fact, renewable energy development has to keep pace with rising global energy demand.

C. In order to end addiction to oil / petroleum and combat global warming, we must focus on real solutions like increasing the energy efficiency of our homes, increasing vehicle fuel efficiency and increasing our sources of clean, renewable energy. We should think of moving to 100 percent energy from renewable sources by end of next decade or so; and for that purpose our and Government’s whole hearted efforts have to be oriented. Our policy, research, strategy etc., have to be achieving towards that goal.

D. One of the most advanced European industrial nations, Germany, is advancing with resolve in a transition to 100 percent energy from renewable resources by 2020. The German government accepts that the goal is technically and economically possible, and has adopted a long-term national policy for the transition. Germany’s most urgent conclusion is that the period lasting until about 2020 comprises “make-or-break” years for the renewable energy transition. It is this conviction that has driven German policymakers to introduce the world’s most aggressive support for renewable energy, to stick with it during the past decade and to guarantee that support for the next 20 to 30 years.

Wind Energy – Renewable energy by harnessing wind power – Answer for Emission problem:

Wind Energy – Renewable energy by harnessing wind power – Answer for Emission problem:

People try to make many assumptions against wind turbines for generation of wind energy; but the fact remains, wind energy is most suitable form of renewable energy we can have to replace coal fired / nuclear powered / and even oil fired power plants in the near future. In support various points are discussed below:

1. Wind power is a clean, renewable source of energy which produces no greenhouse gas emissions or waste products. Power stations are the largest contributor to carbon emissions, producing tones of CO2 each year. We need to switch to forms of energy that do not produce CO2. Just one modern wind turbine will save over 4,000 tones of CO2 emissions annually.

2. The average wind farm will pay back the energy used in its manufacture within 3-5 months of operation. This compares favorably with coal or nuclear power stations, which take about six months.

3. A modern wind turbine is designed to operate for more than 20 years and at the end of its working life, the area can be restored at low financial and environmental costs. Wind energy is a form of development which is essentially reversible – in contrast to fossil fuel or nuclear power stations.

4. A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs depending on the wind speed. Over the course of a year, it will typically generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%. A modern wind turbine will generate enough to meet the electricity demands of more than a thousand homes over the course of a year.

5. All forms of power generation require back up and no energy technology can be relied upon 100%. Variations in the output from wind farms are barely noticeable over and above the normal fluctuation in supply and demand.

6. The cost of generating electricity from wind has fallen dramatically over the past few years. Between 1990 and 2007, world wind energy capacity doubled every three years and with every doubling prices fell by 15%. Wind energy is competitive with new coal and new nuclear capacity, even before any environmental costs of fossil fuel and nuclear generation are taken into account. As gas prices increase and wind power costs fall – both of which are very likely – wind becomes even more competitive, so much so that some time after 2010 wind should challenge gas as the lowest cost power source. Furthermore, the wind is a free and widely available fuel source, therefore once the wind farm is in place, there is no fuel requirement or no waste related costs.

7. In future, we will need a mix of both onshore and offshore wind energy to meet the challenging targets on climate change. At present, onshore wind is more economical than development offshore. However, more offshore wind farms are now under construction. Thus, prices will fall as the industry gains more experience.

8. Wind energy is a benign technology with no associated emissions, harmful pollutants or waste products. In over 25 years and with more than 75,000 machines installed around the world, and there is no report of any body has ever been harmed by the normal operation of wind turbines.

9. The evolution of wind farm technology over the past decade has rendered mechanical noise from turbines almost undetectable with the main sound being the aerodynamic swoosh of the blades passing the tower.

10. We need to act now to find replacement power sources - wind is an abundant resource, and therefore has a vital role to play in the new energy portfolio all over the world.

Average onshore turbines discussed here is of capacity 1.8 MW. For many on-going projects at present the capacity over 2 MW turbines are being installed. Offshore, turbines currently being installed are rated at 3 MW, and it is expected that this will rise to a typical 5 MW per machine by 2010.

Population displacement (migration) due to environmental degradation:

Population displacement (migration) due to environmental degradation:

To “migrate” means to move from one’s habitat. This movement ranges from free or voluntary movement, to forced or involuntary movement. In many cases, people are “displaced” by forces beyond their control, and hence the term “population displacement.” Environmental refugees are those people who have been forced to leave their traditional habitat, temporarily or permanently, because of prolonged environmental degradation / disruption caused by either nature and/or triggered by people, which jeopardized their existence / livelihood seriously affecting the quality of their life.
Population displacement due to environmental degradation is not a recent phenomenon. Historically, people have had to leave their land because it had been degraded (through natural disasters, war or over-­exploitation) and could not sustain them. What is recent is the potential for large movements of people resulting from a combination of resource depletion, the irreversible destruction of the ­environment and population growth (among other factors). The physical environment now is changing in ways that make human populations more vulnerable to environmental stress. As deforestation, global warming and other threats appear a new category of displaced people called environmental refugees have been created. The number of people displaced by environmental degradation is immense.

Recently, according to many, environmental refugees have become the single largest class of displaced persons in the world. As governments do not take official account of this unconventional category, estimates of the number of environmental refugees vary greatly. Countries in Africa and Asia are the most affected as displaced persons in the world because of environmental degradation. People also think that the numbers of environmental refugees are expected to increase ­rapidly. Many authors claim that, environmental degradation is likely to produce “waves of environmental refugees that spill across borders with destabilizing effects” on domestic order and international relations. Migration is a complex phenomenon, and it is difficult to isolate environmental stresses from the web of social, economic, and political relations.
There are numerous examples presented to substantiate the link between environmental change and population movement, but the commonly cited are the Sahel in Africa, El Salvador, Haiti, and Bangladesh. It is well documented that each of these regions or countries has experienced significant environmental stress, notably droughts, deforestation, soil degradation, and flooding. It is also clear that there is a complex array of social, economic and institutional processes at work - rapid population growth, inequitable land distribution, civil war, extreme poverty etc.

If deterioration of the natural resource systems continues, political and social instability will be aggravated, as will economic stagnation and rural poverty. This phenomenon in turn will constrain future economic and social development in the vulnerable developing countries.

There are three important stages in the movement process:
a. Survival—using movement as a means of obtaining relief from environmental stresses;
b. Recovery—where movers are able to use their movement to recover from the problem, and consolidate their position; and finally,
c. Improvement—where a person is able to use movement as a means of enhancing their position and prospects, in which case a return to the place of origin may be less likely to occur.

Migration is a complex phenomenon, and it is not clear in what ways environmental degradation influences a person’s decision to migrate. It is also difficult, if not impossible, to isolate environmental stresses from the complex web of social, economic, and political relations present in everyday living. However, accepting these difficulties, two sets of recommendations are presented below. The first set outlines general recommendations for assisting communities and regions under environmental stress, particularly where that stress may contribute to population movement. The second set provides more specific recommendations.
1. A major emphasis to be given on promoting sustainable development and its ecological, economic and social manifestations. Further, this implies ensuring human security. More specific recommendations include:

(a) Develop a system to help anticipate migrations that may be triggered by environmental disruptions. This could be in the form of an early warning system or simply a continual assessment of the vulnerability of regions and communities to environmental stress.

(b) Focus efforts on identifying adaptation mechanisms and how these mechanisms may be reinforced in vulnerable communities and regions.

(c) Develop case studies of the influences of environmental degradation on migration, with specific consideration paid to the development of procedures for assisting those people affected by environmental disruptions.

(d) Develop better working relationships between organizations devoted to human rights, environment, population and migration.

(e) Involve migrants and refugees directly in the ­development of programs to assist those affected by environmental deterioration.

(f) Recognize the cumulative causality of environmental degradation and population movement, and assist receiving regions to ensure minimal environmental impacts of the migration flows.

(g) Provide development assistance to countries most vulnerable to future environmental change; and

(h) Recognize that human rights and the sustainability of the environment—indeed, human security and all its components—should be the cornerstone of any assistance policies.

2. The more specific policy recommendations focusing on promoting sustainability in resource use, considering thoughtfully the complexities that underlie population growth rates and addressing the inequitable distribution of income and access to resources between and within countries, would be:

(a) An increase in support for women’s reproductive health and rights. Following the outcome of the UN Population Conference in Cairo in 1994, there must be support and funding for a comprehensive perspective on women’s health and human rights.
(b) There must be greater focus on agricultural activities and the role of multi-nationals in aggravating the resource inequities that exist in many countries. This should also include a focus on reducing erosion and deforestation, and increasing the sustainability of small farms in marginal areas.
(c) Greater effort should be made to improve environmental awareness and knowledge at all levels. This includes care for the environment and sustainable resource use.
(d) In this context, an adequate supply of freshwater is crucial. It is also imperative that treated water is recycled for agricultural uses. Inefficient use of water, water loss in urban areas, and the lack of systems to use recycled water greatly affect social welfare.

The complex nature of environment-population ­linkages makes it difficult to develop policy ­recommendations that are as concrete as many would like. However, it is apparent that environmental degradation and resource depletion, often filtered through contexts of poverty and inequity, can ­contribute to population movement.

Degradation of Environment vis-a-vis Growth in Population:

Degradation of Environment vis-a-vis Growth in Population:

The link between population growth and environmental impact seems obvious at first glance: more people consume more resources, damage more of the earth and generate more waste. Humans are a force of nature. As nations develop, they increase consumption. This simple reasoning is true as far as it goes, but the larger picture is more complex. Below few points are given for elaboration:

* A very small proportion of the population consumes the majority of the world's resources. The richest fifth consumes 86% of all goods and services and produces 53% of all carbon dioxide emissions, while the poorest fifth consumes 1.3% of goods and services and accounts for 3% of C02 output.

* Per capita municipal waste grew 30% in developed nations since 1975 and is now two to five times the level in developing nations. At the same time, the waste treatment system is much developed in developed nations as compare to the level in developing nations, thereby, degradation of environment due to municipality waste is much less in developed nations.

* Many have opinion that, an average American's environmental impact is 30 to 50 times that of the average citizen of a developing country such as India; even though most advanced systems and more stringent legislations are followed to mitigate the impacts in developed countries.

* Therefore, the need is to balance the requirements of a growing population with the necessity of conserving earth's natural assets. We have already lost more than a quarter of the planet's birds, and two-thirds of the major marine fisheries are fully exploited, over-exploited or depleted.

* Every 20 minutes, the world adds about 3,500 human lives but loses one or more entire species of animal or plant life - at least 27,000 species per year. This is a rate and scale of extinction that has not occurred in 65 million years.

* Spreading deserts, declining water tables and quality of ground water in a third of the planet are contributing to famine, diseases, social unrest and migration.

* Two thirds of the world's population lives within 100 miles of an ocean, inland sea or freshwater lake: 14 of the world's 15 largest megacities (10 million or more people) are coastal city. Their impacts include growing loads of sewage and other waste, the drainage of wetlands and development of beaches, and destruction of prime fish nurseries.

* Technological advances can mitigate some of the impact of population growth, and market mechanisms raise prices for some diminishing resources, triggering substitution, conservation, recycling and technical innovation so as to prevent depletion. But market systems generally do not take into account environmental costs. No market considers commonly held resources such as groundwater levels or atmospheric and ocean quality. Nor do markets consider earth's "services," such as regulation of climate, detoxification of pollutants or provision of pollinators, much less questions of human equity and social justice.

* It is most certain, an unchecked consumption and rapid population growth are likely to overwhelm technological improvements in affecting the environment. Obviously, the greatest environmental threat comes from both the wealthiest billion people, who consume the most and generate the most waste, and from the poorest billion, who may damage their meager resource base in the daily struggle to avoid starvation. In addition, the billions in between are doing their best to increase their standard of living, in part through increased consumption.

* Although the world's supply of water remains constant, per-capita water consumption is rising twice as fast as world population. Therefore, it can be understood very well that, how severe the situation of water scarcity would be where most billions are lived.

* The world's forests have shrunk from 11.4 to 7.3 square kilometers per 1,000 people since 1970. The loss is concentrated in developing countries, mostly to meet the demand for wood and paper by the industrialized world. Wild species are becoming extinct 50 to 100 times faster than they naturally would.

* Over the last 50 years, 17% of the planet's soils have been severely degraded. That's nearly 2 billion hectares, the size of China and India combined.

* The global emission of carbon dioxide, a "greenhouse gas" that causes global warming and disruption in weather patterns, has increased enormously, largely from deforestation and the burning of fossil fuels. The atmosphere now contains 35% more CO2 than at the beginning of the industrial revolution. It is extremely worrisome.

Population growth – Effect on food supplies and environment:

Population growth – Effect on food supplies and environment:

As the world population continues to grow in almost all continents, great pressure is being placed on arable land, water, energy, and biological resources to provide an adequate supply of food while maintaining the integrity of our ecosystem. As the world population grows, the food problem will become increasingly severe. The most venerable will be population in developing countries. The per capita availability of world grains, which make up 80 per cent of the world's food, has been declining for the past 25 years. Certainly with a quarter million people being added to the world population each day, the need for grains and all other food will reach unprecedented levels.

A. Below, world population and its growth trend is given.

* 10,000 years ago, 10 million people,

* By 1850, population was 1 billion,

* 80 more years to reach 2 billion (1930),

* 45 years, it doubled again (4 billion in 1975),

* 12 years to reach to reach 5 billion (1987),

* 6 billion in 1999,

* By the year 2020, there will be 8 billion?

There are ¼ million people added to the planet per day. This exponential growth is mostly happening in developing nations.

B. More than 99 per cent of the world's food supply comes from the land, while less than 1 per cent is from oceans and other aquatic habitats. The continued production of an adequate food supply is directly dependent on ample fertile land, fresh water, energy, plus the maintenance of biodiversity. As the human population grows, the requirements for these resources also grow. Even if these resources are never depleted, on a per capita basis they will decline significantly because they must be divided among more people.

At present, fertile agricultural land is being lost at an alarming rate. More than one-third of the world's cultivated land (1.5 billion hectares) has already been abandoned during the past 40 years because erosion has made it unproductive and this degradation of agricultural land is almost permanent. Most replacement of eroded agricultural land is now coming from marginal and forest land. Thus, pressure for agricultural land accounts for 60 to 80 percent of the world's deforestation. The shortage of productive fertile land combined with decreasing land productivity is the major cause of current food shortages and associated human malnutrition.

C. Water is another critical item for all crops. Massive amounts of water are required during the growing season for cultivation. In fact, agricultural production consumes more fresh water (about 87 per cent of the world's fresh water) than any other human activity. In many countries, people are facing shortage of fresh water. Competition for water resources among individuals, regions, and countries and associated human activities is already occurring with the current world population. Water resources, critical for irrigation, are under great stress as populous cities, states, and countries require and withdraw more water from rivers, lakes, and aquifers every year. A major threat to maintaining future water supplies is the continuing over-draft of surface and ground water resources.

D. Fossil energy is another prime resource used for food production. Nearly 80 per cent of the world's fossil energy used each year is used by the developed countries. The intensive farming technologies of developed countries use massive amounts of fossil energy for fertilizers, pesticides, irrigation, and for machines as a substitute for human labor. In developing countries, fossil energy has been used primarily for fertilizers and irrigation to help maintain yields rather than to reduce human labor inputs. Because fossil energy is a finite resource, its depletion accelerates as population needs for food and services escalate. Thus, cost of fuel increases everywhere.

E. Certainly improved technology will assist in more effective management and use of resources, but it cannot produce an unlimited flow of those vital natural resources that are the raw materials for sustained agricultural production. For instance, fertilizers enhance the fertility of eroded soils, but humans cannot make topsoil. Indeed, fertilizers made from finite fossil fuels are presently being used to compensate for eroded topsoil. A productive and sustainable agricultural system depends on maintaining the integrity of biodiversity. Strategies for the future must be based on the conservation and careful management of land, water, energy, and biological resources needed for food production.

F. Yet none of these measures will be sufficient to ensure adequate food supplies for future generations unless the growth in the human population is simultaneously curtailed. Several studies have confirmed that to maintain a relatively high standard of living throughout the world, the optimum world population should be less than 2 billion. Therefore, from now until an optimum population is achieved, strategies for the conservation of land, water, energy, and biological resources are to be implemented effectively. Maintaining a sound and productive environment allover its protection is essential.

Expected impacts of global warming:

Expected impacts of global warming – would certainly be very harmful and dangerous:

A large body of scientific studies, exhaustively reviewed, has produced a long list of possibilities of impacts of global warming. Nobody can say that any of the items on the list are certain to happen. But most of the climate experts agree that the impacts listed below are more likely to happen. The exact timings, for them, are difficult to predict, but they are in the opinion that, if humanity manages to begin restraining its emissions within the next few decades, so that greenhouse gases do not rise beyond twice the pre-industrial level (we are already 35% above it and rising each year, at an accelerating rate) the consequences would certainly be very dangerous - probably including a radical reorganization and impoverishment of many of the ecosystems that sustain our civilization. Expected impacts are:

(1) Most places will continue to get warmer, especially at night and in winter. The temperature change will benefit some regions, at least for a time, while harming others like, patterns of tourism will shift. The warmer winters will benefit health in some areas, but globally, mortality will rise due to summer heat waves and other effects.

(2) Sea levels will continue to rise for many centuries. The last time the planet was 3°C warmer than now, the sea level was roughly 5 meters higher. That submerged coastlines where many millions of people now live. Also, storm surges will cause emergencies.

(3) Weather patterns will keep changing, probably toward an intensified water cycle with stronger floods and droughts. Most regions that are now subject to droughts are expected to get drier (because of warming as well as less precipitation), and most wet regions will get wetter. Changes in extreme weather events are hard to predict, but in some regions storms with more intense rainfall are liable to bring worse floods. Mountain glaciers and winter snowcap will shrink, jeopardizing many water supply systems. Each of these changes has already begun to happen in some regions.

(4) Ecosystems will be stressed, although some managed agricultural and forestry systems will benefit, at least in the early decades of warming. Uncounted valuable species, especially in the Arctic, mountain areas, and tropical seas, must shift their ranges. Many that cannot will face extinction. A variety of pests and tropical diseases are expected to spread to warmed regions. Each of these problems has already been observed in numerous places.

(5) Increased carbon dioxide levels will affect biological systems independent of climate change. Some crops will be fertilized, as will some invasive weeds (the balance of benefit vs. harm is uncertain). The oceans will continue to become markedly more acidic, gravely endangering coral reefs, and probably harming fisheries and other marine life.

(6) There will be significant unforeseen impacts. Most of these will probably be harmful, since human and natural systems are well adapted to the present climate.

Climate Change Science – Global warming – an overview:

Climate Change Science – Global warming – an overview:

A. Climate change is a global issue that affects us all. Changes in climate patterns mean that extreme weather events such as heat waves, floods, storms, droughts and bushfires will become more frequent, more widespread or more intense. Climate change science is providing a better understanding of the causes, nature, timing and consequences of climate change. Climate change science is a very complex subject. Various investigations, studies, reports suggest that world is warming up, but how this will affect us in the future is difficult to qualify. Climate change is the result of changes in our weather patterns because of an increase in the Earth's average temperature. The weather elements at a given location vary from time to time throughout the year, but generally are expected to remain within set limits over a long time period. This is known as our climate. This natural variation in temperature ensures we have cold and warm years. This is actually a natural and essential feature of our atmosphere without which our planet would be uninhabitable.

B. If go back to history of climate change and find people behind postulating the probable cause of it; we may more or less say that in the 1930s people started realizing that the United States and North Atlantic region had warmed significantly during the previous half-century. Scientists supposed this was just a phase of some mild natural cycle, with unknown causes. Only one lone voice, the amateur G.S. Callendar, insisted that greenhouse warming was on the way. In the 1950s, Callendar's claims provoked a few scientists to look into the question with improved techniques and calculations. The new studies showed that, contrary to earlier crude estimates, carbon dioxide could indeed build up in the atmosphere and should bring warming. Painstaking measurements drove home the point in 1961 by showing that the level of the gas was, in fact, rising, year by year. In the early 1970s, the rise of environmentalism raised public doubts about the benefits of human activity for the planet. Curiosity about climate turned into anxious concern. Alongside the greenhouse effect, some scientists pointed out that human activity was putting dust and smog particles into the atmosphere, where they could block sunlight and cool the world. Most scientists agreed on was that they scarcely understood the climate system, and much more research was needed. Research activity did accelerate, including huge data-gathering schemes that mobilized international fleets of oceanographic ships and orbiting satellites. People have come to know that, this is caused by increases in greenhouse gases in the Earth's atmosphere. By 2000, scientists knew the most important things about how the climate could change during the present century.

C. Therefore, when we talk about global warming, as described above, we generally talk about the 'greenhouse effect'. This process works by the principle that certain atmospheric gases (called greenhouse gases) allow short wave radiation from the sun to pass through them unabsorbed, while at the same time absorbing some of the long wave radiation reflected back to space. The net result; more heat is received from the sun than is lost back to space, keeping the earth's surface warmer than it would otherwise be. Man, in the process of industrialization and development, is adding to and changing the levels of the gases responsible for the greenhouse effect and is therefore enhancing this warming.

D. The effect of global warming is that, global ice sheets have decreased, so has global snow cover. There have been warmer periods in the history – some millions of years ago. However, the present rise is the most rapid rise in temperature since the end of the last ice age. Carbon dioxide (CO2) is the gas most significantly responsible for greenhouse effect. Plant respiration and decomposition of organic material release more than 10 times the CO2 than released by human activities, but these releases have generally been in balance during the centuries. Since the industrial revolution amounts have increased by 30%. Other greenhouse gases include Methane, Nitrous oxide, CFC's (manmade) and Ozone. The major problem is that these gases can remain in the atmosphere for decades. The combustion of fossil fuel (oil, natural gas and coal) by heavy industry and other human activities, such as transport and deforestation, are the primary reasons for increased emissions of these harmful gases. Aerosol, from human made sulfur emission, also increases in the atmosphere along with CO2. The small particles of aerosol have a property to reflect back some of the sunlight and hence act to slow down the cooling. However where carbon dioxide can remain in the atmosphere for 100 years, sulfate aerosols only last a few days and can be easily removed by rain (acid rain). Therefore they only temporarily mask the full effect of CO2.

E. In order to try and predict possible consequences of this warming for the future, researchers use climate modeling to simulate the climate and oceans over many decades. Climate models also predict changes in rainfall and rise in sea level. Sea level rises will be due to thermal expansion of the ocean along with the melting glaciers and mountain snow and ice. The recent estimate of sea level rise is by more than 50cm by 2100, but this will vary considerably with location.