Global Warming - Each one degree rise in the temperature of the world's oceans is equivalent to 1.4 BILLION one Megaton atom bombs!!!

Global Warming - Each one degree rise in the temperature of the world's oceans is equivalent to 1.4 BILLION one Megaton atom bombs!!!

We all know, the earth is surrounded by a cover of gasses as atmosphere. This atmosphere allows most of the light to pass through, which reaches the surface of earth.

This light from sun is absorbed by the earth surface and converts into heat energy. This heat energy is re-emitted by the surface of the earth during night.

Due excessive presence of some gasses in the atmosphere, this escape of heat from earth surface is prevented, resulting in heating of earth called ‘global warming’.

The gasses which are responsible for causing global warming are called ‘greenhouse gasses’. Carbon dioxide is one of the most important greenhouse gases. This carbon dioxide mostly comes to atmosphere as air pollution from vehicles, coal-fired power plants and other industries burning fossil fuels. Human population increase and large scale deforestation are also responsible for carbon dioxide generation.

Thus, Global Warming adds energy to the Earth's biosphere.

The climate change which we are experiencing is due to global warming.

Heat is the fuel of weather systems. More heat, more extreme weather.

Energy drives the water cycle.

The more energy there is the faster the water cycle is driven and the more extreme the weather patterns become.

Each one degree rise in the temperature of the world's oceans is the equivalent to 1.4 BILLION one Megaton atom bombs; that is a lot of energy! This tremendous amount of devastating energy, generating because of our faulty creation “Global Warming” is responsible for the present climate change.

Thus, it shouldn't be surprising that the result is more extreme weather. More rain, more drought and more storms.

The harmful effects of presence of greenhouse gasses in atmosphere are global warming, climate change, ozone depletion, sea level rise, adverse effects on biodiversity etc.

Therefore, our prime responsibility is not to promote any industrialization which enhances carbon emission, rather than reduction.

Proper energy mix, which generates electricity without emission, is essential. Energy mix should include –

(a) substantial enhancement of Nuclear power in the industrialized countries;

(b) only clean coal technology / green coal to be used for power generation;

(c) wherever possible tap hydro-power;

(d) substantial effort needed to enhance research and implementation for provision of generation of clean energy from renewable sources such as solar and wind.

Faster ocean warming due to climate change – One of the reasons of catastrophic sea level rising:

Faster ocean warming due to climate change – One of the reasons of catastrophic sea level rising:

a. It has been reported recently by some of the climate research agencies in US, Australia, UK etc. that, oceans all over the world are getting warmed at a much faster rate than it used to be earlier or what was thought to be. It is estimated that, the rate of warming of world’s oceans is about 50% faster over the last half century than it was thought previously. Thus, world’s oceans have warmed more quickly due to climate change than expected.

b. It may be noted, higher the ocean temperatures, higher the expansion of ocean water – which contributes to rise in sea levels. Expansion ocean water means more floods, submerging smaller island nations, threatening to wreak havoc in low-lying places and densely-populated delta regions around the globe. A third of the world’s population living within 50 km of the coasts and a great proportion and a large proportion of them live much closer to the shoreline. Even a modest sea level rise could inundate low-lying regions, accelerate coastal erosion and force the relocation of communities and infrastructures.

c. Rising sea levels are driven by two things – (i) the thermal expansion of sea water, and (ii) additional water from melting sources of ice. Both these processes are caused by global warming.

d. For example, the glaciers or ice sheet that cover Arctic region contains enough water to raise world ocean levels by seven meters, which would bury sea-level cities from Dhaka to Shanghai in Asia and many more similar cities in other parts of the world. If the Greenland and the West and East Antarctica ice sheets were to melt, it would be enough to raise the sea level by approximately 65 meters. A one-foot rise in sea level might well translate to a 200-foot retreat of shoreline. Therefore, it could be imagined about the future coastal map how catastrophic it would be. Among the most vulnerable are countries with large populations in deltaic coastal regions such as Bangladesh, Vietnam, China and Egypt. Two populous island nations, the Philippines and Indonesia, have millions who face displacement from their homes from sea level rise. Several small island state nations including the Maldives in the Indian Ocean and the Marshall Islands and Tuvalu in the Pacific could face extinction.

e. Global heating effects are strong in melting of snow and ice, rising global mean sea level, widespread changes in precipitation amounts, ocean salinity, wind patterns and aspects of extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones. The rate of rise in temperatures depends on if and how fast emissions are reduced and on possible adverse feedbacks in the climate system. Temperatures are sure to rise faster in the next decades as well. Experts opine that, hot extremes, heat waves, and heavy precipitation events will continue to become more frequent. It is certain that the ocean would become more acid from taking up more carbon dioxide.

f. Therefore, it is very important, now, to figure out and estimate how much each of these factors contributes to rising sea levels. Further, it is critically important to understand global warming, climate change and forecasting future ocean temperature rise, as well. The fact is, up to now there has been a perplexing gap between the projections of computer-based climate models, and the observations of scientific data gathered from the world’s oceans.

Thinning of ozone layer – Effective checking would reduce global warming and enhance standard of environment:

Thinning of ozone layer – Effective checking would reduce global warming and enhance standard of environment:

For nearly a billion years, ozone molecules in the atmosphere have protected life on Earth from the effects of ultraviolet rays. It is a form of oxygen (O2). We all know that, oxygen we need to live and breathe. Normal oxygen consists of two oxygen atoms. Ozone, however, consists of three oxygen atoms and has the chemical formula O3. Ozone is formed when an electric spark is passed through oxygen. Over millions of years the action of sunlight and specifically the action of ultra violet light or UV on oxygen has created a layer of ozone high up in the atmosphere. This ozone layer resides in the stratosphere and surrounds the entire Earth. The action of UV light on this layer both destroys and creates ozone, a constant process going on silently. Thus, this process of absorbing portion of UV light, protecting us from the harmful exposure. In fact, UV-B radiation (280- to 315- nanometer (nm) wavelength) from the Sun is partially absorbed in this ozone layer. As a result, the amount of UV-B reaching Earth’s surface is greatly reduced. UV-A (315- to 400-nm wavelength) and other solar radiation are not strongly absorbed by the ozone layer. Human exposure to UV-B increases the risk of skin cancer, cataracts, and a suppressed immune system. UV-B exposure can also damage terrestrial plant life, single cell organisms, and aquatic ecosystems. In the past 60 years or so human activities have contributed to the deterioration of the ozone layer to a great extent.

Mechanism of Ozone hole - The criticality of ozone layer can be understood from the fact that, only 10 or less of every million molecules of air is ozone. The majority of these ozone molecules reside in a layer between 10 and 40 kilometers above the surface of the Earth known as stratosphere. Each spring in the stratosphere over Antarctica (spring in the southern hemisphere is from September through November.), atmospheric ozone is rapidly destroyed by chemical processes. As winter arrives, a vortex of winds develops around the pole and isolates the polar stratosphere. When temperatures drop below -78°C, thin clouds form of ice, nitric acid, and sulfuric acid mixtures. Chemical reactions on the surfaces of ice crystals in the clouds release active forms of CFCs. Ozone depletion begins, and the ozone “hole” appears.

Over the course of two to three months, approximately 50% of the total column amount of ozone in the atmosphere disappears. At some levels, the losses approach 90%. This has come to be called the Antarctic ozone hole. In spring, temperatures begin to rise, the ice evaporates, and the ozone layer starts to recover.

Thus, ozone "hole" is a reduction in concentrations of ozone high above the earth in the stratosphere. The ozone hole is defined geographically as the area wherein the total ozone amount is less than 220 Dobson Units. The ozone hole has steadily grown in size and length of existence over the past two and half decades. Now, the size of ozone hole over Antarctica is estimated to be about 30 million sq. km.

It has been observed that, man-made chlorines, primarily chloroflourobcarbons (CFCs), contribute to the thinning of the ozone layer and allow larger quantities of harmful ultraviolet rays to reach the earth.

Effects of ozone layer depletion - UV-B (the higher energy UV radiation absorbed by ozone) are generally accepted to be a contributory factor to skin cancer. In addition, increased surface UV leads to increased troposphere ozone, which is a health risk to humans. The increased surface UV also represents an increase in the vitamin D synthetic capacity of the sunlight. The cancer preventive effects of vitamin D represent a possible beneficial effect of ozone depletion. In terms of health costs, the possible benefits of increased UV irradiance may outweigh the burden. In other words, a thinning of the ozone layer is the key factor in the greenhouse effect, and exposes life on Earth to excessive ultra violet radiation, which can increase skin cancer and cataracts, reduce immune-system responses,

As far as effect on plant is concerned, an increase of UV radiation would be expected to affect crops. A number of economically important species of plants, such as rice, depend on cyanbacteria residing on their roots for the retention of nitrogen. Cyanobacteria are sensitive to UV light and they would be affected by its increase. Thinning of the ozone layer also interfere with the photosynthetic process of plants,

Research has shown a widespread extinction of oceanic phytoplankton (a crucial source of food to aquatic life) is because of thinning of ozone layer. Researchers speculate that the extinction of plankton was caused by a significant weakening of the ozone layer at that time when the radiation from the supernova produced nitrogen oxides that catalyzed the destruction of ozone. Plankton is particularly susceptible to effects of UV light, and is vitally important to marine food webs.

Biotechnology in agriculture – Bid to eradicate hunger by increase in yield - To overcome climate challenges:

Biotechnology in agriculture – Bid to eradicate hunger by increase in yield - To overcome climate challenges:

Now it is known fact that, because of global warming, climate change is taking place. The effects of climate change are erratic behavior of nature, such as intensified drought, flood, cyclone etc. Now, it has become challenge to us to grow more food despite having erratic changes in world climate and nature. Further, explosive growth of population worldwide and need of using ethanol (bio-fuel) blended gasoline made us think about the increase in agriculture production.

Under the above backdrop, it is felt, biotechnology in agriculture would become the key to feeding growing population; take care of agricultural production in the adverse climatic conditions both for food and production of ethanol. Overcoming climate challenges like crop-killing droughts etc., are very important, for which science of biotechnology can be very much useful. Biotechnology scientists believe that, it can increase corn and soybean yields by 40 per cent over the next decade. New tools and biotechnology can work in conjunction with better breeding and higher yielding seed to give maximum benefit to human being.

We all know that, crop shortages this year have sparked riots in some countries and steep price hikes in markets around the globe causing lot of miseries and death due to starvation.

Now the question is how to address these issues effectively in order to achieve sufficient agricultural production to overcome crop shortages. Despite persistent reluctance in number of nations and environmental groups, genetically modified (GM) crops have been on the rise. Growing food and bio-fuel demands have been helping push growth of GM crops.

Water scarcity is one of the major problems, which is expected in doubling in severity over the next few decades even as the world population explodes, and will only be worsened by global warming climate change. With about nine billion people expected to populate the globe by next couple of decades and about 85 per cent of the population seen in lesser developed countries, decreased land for agriculture and multiple demands on water use will come hand in hand with an expected doubling in food demand.

Scientists opine that, by using conventional and biotech genetically modifications, crops can be engineered to yield more in optimum as well as harsh climatic conditions, can be made healthier, pest resistant and can be developed in ways that create more energy for use in ethanol production. As food prices increase worldwide and shortages causing starvation deaths; use of GM crops certainly brings a more practical perspective to the debate. Number of tools can be brought to bear with biotechnology to solve the crisis.

As discussed, the most widespread application of genetic engineering in agriculture by far is in engineered crops. Thousands of such products have been field tested and over a dozen have been approved for commercial use. The traits most commonly introduced into crops are herbicide tolerance, insect tolerance, and virus tolerance. In recent time, number of companies is engaged in developing genetically engineered seeds such as, disease-resistant biotech wheat, drought-resistant corn, crops that need less fertilizer and corn that more efficiently can be turned into ethanol. Biotechnology can also address health concerns of consumer and can contribute to healthier life as in the case of soybean oil where about 90% reduction in saturated fat and trans fat has been achieved.

At present, it is a challenge to world community to increase access to agriculture’s tools and any nation’s focus should be on its self-sufficiency, which by adopting biotechnology can be achieved, it is felt. Agriculture is an extremely complex system and needs expertise in technology to sustain an equitable growth for the farmers. Therefore, in my opinion, it is important to create partnerships, relationships among both the biotechnologists and farmers in order to bring practicality to address the problems.

Abnormal rise in greenhouse gas, methane, in the earth atmosphere causing arctic ice to vanish in a couple of years!!

Abnormal rise in greenhouse gas, methane, in the earth atmosphere causing Arctic ice to vanish in a couple of years!!

It has been reported that, due to rapid, unchecked and unethical industrialization in many parts of the globe, the concentration of methane, a very prominent greenhouse gas, has been rising and in last one year alone it has risen by about 0.5%. We all know that, methane is the second most important gas causing man-made climate change. Each molecule causes about 25 times more warming than a molecule of CO2, though it survives for shorter times in the atmosphere before being broken down.

Further, it has also been known to us that, already global climate is at great disastrous condition because of present rise in carbon dioxide (CO2) levels, which is significantly higher than the average annual increase for the last 30 years. It has also been recently reported that, CO2 concentration has risen by 2.4 parts per million (ppm) in last one year; as against the average annual increase of 1.65ppm between 1979 and 2007. Thus, it shows evidence that, concentrations of greenhouse gases are rising faster than they were a decade ago. The methane concentration figure is more awesome and potentially of more concern.

Because of the above abnormal rise in greenhouse gases in last one year or so, scientists fear that, it could reflect melting of permafrost and drying of tropical wetlands more rapidly. It has also been reported that, concentrations of greenhouse gases have been more or less stable since about 1999 and thereafter rapid increases.

Industrial reforms in Asia, Europe and South American countries in last one decade reflected abnormal rise in greenhouse gases, especially of carbon dioxide and methane. Changes of methods rice farming processes and the capture of methane from landfill sites contributed to this rise, it is felt. Also, possibilities of release of methane from frozen zones of the world, notably the Arctic permafrost, as they warm cannot be ruled out.

The rapid unchecked increase in coal fired industries (without cleaning coal) such as power plants, steel plants etc., are mostly responsible for rise in concentration of CO2.

The sustained rise of greenhouse gases along with El Nino and La Nina (opposite of El Nino) conditions, the earth is experiencing warming effects. As per the new scientific analysis, because of the warming, the arctic snow melted most rapidly in last one year. They also predict that, the sea level could rise by more than one and half meters by another half century or so. Sea level rise of this magnitude would have major impacts on low-lying countries such as Bangladesh. Scientists also fear that, due to abnormal rise in average global temperature, in next five of six years there may not be any arctic ice left during summer.

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%>

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.

Rise in global warming - Ocean might have become 'saturated' with our emissions – An alarm bell:

Rise in global warming - Ocean might have become 'saturated' with our emissions – An alarm bell:

When the industrial revolution started, the level of CO2 in the atmosphere was around 280 parts per million by volume (ppmv) but that has risen to around 380ppmv due to our burning of fossil fuels. Because of tremendous rise in CO2 (about 35% rise) the global warming scenario has been deteriorated or faster. The melting of arctic ice, severe climate changes are some of the effects among many, of the global warming. This unexpected growth of CO2 level in the atmosphere, scientists suspect, is due to mainly two reasons –

(i) Inefficiency in the use of fossil fuels which increased the CO2 level by 17% and

(ii) Other 18% came from a decline in the natural ability of land and oceans to soak up CO2 from the atmosphere, i.e., decline in global carbon sinks. In addition, the growth of global population is responsible for significant growth of atmospheric CO2, as well.

A. The decline in global sink (there are two major carbon sinks in the biological cycle: the oceans and the land "biosphere", which includes plants and the soil) efficiency suggests that stabilization of atmospheric CO2 is even more difficult to achieve than previously thought. Study suggests, about half of emissions from human activity are absorbed by these natural "CO2 sinks" but it has been observed that, the efficiency of these sinks has fallen. Scientists believe global warming might get worse if the oceans soak up less of the greenhouse gas.

B. The weakening of the Earth's ability to cope with greenhouse gases is thought to be a result of changing wind patterns over seas and droughts on land. Nearly half of the decline in the efficiency of the ocean CO2 sink is, expected, due to the intensification of the winds in the Southern Ocean, study suggests. The declining effect is also being seen in the North Atlantic, as per the recent study.

C. In fact, the researchers are clueless about the exact reasons, whether this change in behavior of ocean is due to climate change or to natural variations. It is a tremendous surprise and troublesome factor because there were grounds for believing that in time the ocean might become 'saturated' with our emissions - unable to soak up any more. This phenomenon of ocean being saturated, leave us with all our emission to heat-up our globe – results rapidity in global warming.

D. We have to find out the ways to deal with this rapid pace in global warming. Implementation of carbon sink technology, iron fertilization of Southern oceans etc., have to be thought of. The major responsible factors such as, the issues like reduction of emission of greenhouse gasses in the atmosphere are to be tackled efficiently.

MOST IMPORTANT:

WE MUST REDUCE OUR CONSUMPTION OF NON-RENEWABLE RESOURCES.

WE MUST REDUCE THE GREENHOUSE GASES WE RELEASE.

Carbon Dioxide Emission by Combustion Fuels:

Carbon Dioxide Emission by Combustion Fuels:

A. Environmental emission of carbon dioxide - CO2 - from fuels like coal, oil, natural gas, LPG and bio energy are responsible for global warming.

To calculate the CO2 emission from a fuel, the carbon content of the fuel are multiplied by the ratio of the molecular weight of CO2 (44) to the molecular weight of carbon (12) -> 44/12 = 3.7.

Approximately environmental emission of Carbon Dioxide – CO2 - from the combustion of different fuels can be approximated from the table below:

Fuel	Carbon Content (kg C/kg fuel)	Energy Content (kWh/kg)	Emission of CO2 (kg CO2/kWh)
Coal (bituminous/anthracite)	0.75	7.5	0.37
Gasoline	0.9	12.5	0.27
Diesel	0.86	11.8	0.24
Light Oil	0.7	11.7	0.26
Natural Gas, Methane	0.75	12	0.23
LPG - Liquid Petroleum Gas	0.82	12.3	0.24
Bioenergy	0	-	0

B. Bioenergy is produced from biomass derived from any renewable organic plant, such as:

(a) Dedicated energy crops and trees;

(b) Agricultural food and feed crops;

(c) Agricultural crop wastes and residues;

(d) Wood wastes;

(e) Aquatic plants;

(f) Animal wastes;

(g) Municipal wastes and other waste materials

Emissions of CO2 can contribute to climate change. Combustion of bioenergy do not add to the total emission of carbon dioxide as long as the burned biomass do not exceed the renewed production. (Emission of CO2 from combusting wood is in reality approximately 0.18 kg/kWh)

C. A variety of biofuels can be made from biomass resources, such as,

(a) Ethanol;

(b) Methanol;

(c) Bio-diesel;

(d) Fischer-Tropsch diesel;

(e) Gaseous fuels like hydrogen or methane.

The adverse effects of global warming:

The adverse effects of global warming:

Over last 10000 years temperature remained remarkably stable across the globe, changing by little more than 2 degree Fahrenheit on an average. Even during the ‘Little Ice Age’, which lasted from the 1300 AD to 1850 AD, which resulted advancing of glaciers, average temperatures were little more than 2 degree Fahrenheit. The effects of global warming could change average temperatures five times as much as little ice age did – though in the opposite direction. Over the next century, the rate of the effects of global warming should follow a steep upward curve.

The adverse effects of global warming are enormous. The effects are already being felt on our planet, on human life, plants and animals worldwide. The predicted effects of global warming on the environment and for human life are numerous and varied. It is generally difficult to attribute specific natural phenomena to long-term causes, even though, some effects of recent climate changes already we are witnessing; rising sea levels, glacier retreat, arctic shrinkage, and altered patterns of agriculture are cited as direct consequences. Among secondary and regional effects extreme weather events, expansion of tropical diseases, changes in the timing of seasonal patterns in ecosystems, and drastic economic impact are predicted.

Major adverse effects of global warming are listed below:

1. Polar ice caps melting - The ice caps melting is a four-pronged danger.

(a) It will raise sea levels. There are more than 5,773,000 cubic miles of water in ice caps, glaciers, and permanent snow. According to the National Snow and Ice Data Center, if all glaciers melted today the seas would rise about 230 feet. This may not happen at once; but sea level will rise certainly and consequently, low lying areas will be submerged.

(b) Melting ice caps will throw the global ecosystem out of balance. The ice caps are fresh water, and when they melt they will desalinate the ocean, or in plain English - make it less salty. The desalinization of the gulf current will distort ocean currents, which regulate temperatures. It will give very confusing and irregular pattern of cooling and warming effects in some areas.

(c) Temperature rises and changing landscapes in the artic circle will endanger several species of animals. Only the most adaptable will survive.

(d) Global warming will certainly reduce ice caps substantially. Ice caps are white, and reflect sunlight, much of which is reflected back into space, further cooling Earth. If the ice caps melt, the only reflector is the ocean. Darker colors absorb sunlight, further warming the earth.

2. Increased probability and intensity of droughts and heat waves - Although some areas of Earth will become wetter due to global warming, other areas will suffer serious droughts and heat waves. Africa will receive the worst of it, with more severe droughts also expected in Europe. Water is already a scarce commodity in Africa, and global warming will worsen the conditions.

3. Warmer waters and more hurricanes - As the temperature of oceans rise, so will the probability of more frequent and stronger hurricanes.

4. Spread of disease - As northern countries warm, disease carrying insects migrate north, bringing plague and disease with them.

5. Economic consequences - Most of the effects of global warming will not be good. These effects bring economic consequences badly for almost all the countries of the world.