Posts Tagged 'Global Warming'

Indian Rainforests

An article by Mohan Pai

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The Indian Rainforests


Rainforests – the Lungs of the Planet Earth
Tropical rainforests are vital to the global ecosystem and human existence. They are a world like no other and are unparalleled in terms of their biological diversity. Tropical rainforests are a natural reservoir of genetic diversity which offers a rich source of medicinal plants, high-yield foods, and a myriad of other useful forest products. They are an important habitat for migratory animals and sustain as much as 50 percent of the species on Earth, as well as a number of diverse and unique indigenous cultures. Tropical rainforests play an elemental role in regulating global weather in addition to maintaining regular rainfall, while buffering against floods, droughts, and erosion. They store vast quantities of carbon, while producing a significant amount of the world’s oxygen. Rainforests once covered 14% of the earths surface and even though they now only cover 6% of the earth, they are home to almost half of the worlds population of mammals, amphibians, reptiles, insects, bird life and plant life.
Tropical rainforests are located in a band around the equator (Zero degrees latitude) in the area between the Tropic of Cancer (23.5° North latitude) and the Tropic of Capricorn (23.5° South latitude).This 3,000 mile (4800 kilometres) wide band is known as the ‘tropics’.

The equator is a line that circles the centre of our global world and is situated halfway between the north and south poles. Temperatures at the equator are high. These high temperatures cause accelerated evaporation of water, which results in frequent rain in rainforests in the tropics.

World Rainforests
 
Tropical rainforests are found between latitudes 10° N and 10° S. This includes the Amazon Basin of South America, the Zaire Basin of Africa and the islands and peninsulas of South-east Asia.In Southeast Asia, the tropical rainforests are found in India, Bangladesh, Sri Lanka, Malaysia, Brunei, Indonesia, Burma and Papua New Guinea. The rainforests found in India, Bangladesh and Sri Lanka are in small patches and strips, while on the other hand, Indonesia contains one-tenth of the world’s rainforest and 40% of all Asian rainforests! However sadly, as Indonesia is progressing further into modernisation, it is losing its rainforests to commercial logging and human settlements. Malaysia too has lost about two third of its lowland forest to plantations. On a brighter side, Papua New Guinea still has areas of rainforest yet to be disturbed, due to its mountainous terrain. Papua New Guinea is home to many amazing animals, one being the largest butterfly in the world; the Queen Alexandra’s birdwing. Its wing span can reach up to 10 inches wide!
Although they cover less than 2 percent of Earth’s surface, they house an estimated 50 percent of all life on the planet. The immense numbers of creatures that inhabit the tropical rainforests are so great—an estimated 50 million species— they are almost incomprehensible. The sheer range of numbers alone suggests the limited extent of our knowledge of these forests. For example, whereas temperate forests are often dominated by a half dozen tree species or fewer that make up 90 percent of the trees in the forest, a tropical rainforest may have more than 480 tree species in a single hectare (2.5 acres). A single bush in the Amazon may have more species of ants than the entire British Isles. This diversity of rainforests is not a haphazard event, but is the result of a series of unique circumstances.
Layers
A tropical rainforest is typically divided into four main layers, each with different plants and animals adapted for life in that particular area: the emergent, canopy, understory, and forest floor layers.

Emergent layer
The emergent layer contains a small number of very large trees called emergents, which grow above the general canopy, reaching heights of 45-55 m, although on occasion a few species will grow to 70-80 m tall. They need to be able to withstand the hot temperatures and strong winds in some areas. Eagles, butterflies, bats, and certain monkeys inhabit this layer.

Diagram: Coutesy Animal Corner
 

Canopy layer
The canopy layer contains the majority of the largest trees, typically 30-45 m tall. The densest areas of biodiversity are found in the forest canopy, a more or less continuous cover of foliage formed by adjacent treetops. The canopy, by some estimates, is home to 50 percent of all plant species, suggesting that perhaps half of all life on Earth could be found there. Epiphytic plants attach to trunks and branches, and obtain water and minerals from rain and debris that collects on the supporting plants. The fauna is similar to that found in the emergent layer, but more diverse. A quarter of all insect species are believed to exist in the rainforest canopy. Scientists have long suspected the richness of the canopy as a habitat, but have only recently developed practical methods of exploring it. As long ago as 1917, naturalist William Beebe declared that “another continent of life remains to be discovered, not upon the Earth, but one to two hundred feet above it, extending over thousands of square miles.” True exploration of this habitat only began in the 1980s, when scientists developed methods to reach the canopy, such as firing ropes into the trees using crossbows. Exploration of the canopy is still in its infancy, but other methods include the use of balloons and airships to float above the highest branches and the building of cranes and walkways planted on the forest floor. The science of accessing tropical forest canopy using airships, or similar aerial platforms, is called dendronautics.

Understory layer
The understory layer lies between the canopy and the forest floor. The understory (or understorey) is home to a number of birds, snakes, and lizards, as well as predators such as jaguars, boa constrictors, and leopards. The leaves are much larger at this level. Insect life is also abundant. Many seedlings that will grow to the canopy level are present in the understory. Only about 5 percent of the sunlight shining on the rainforest reaches the understory. This layer can also be called a shrub layer, although the shrub layer may also be considered a separate layer.

Forest floor
The forest floor, the bottom-most layer, receives only 2 percent of sunlight. Only plants adapted to low light can grow in this region. Away from riverbanks, swamps, and clearings
where dense undergrowth is found, the forest floor is relatively clear of vegetation because of the low sunlight penetration. It also contains decaying plant and animal matter, which disappears quickly due to the warm, humid conditions promoting rapid decay. Many forms of fungi grow here which help decay the animal and plant waste. It takes up to 20 minutes for rain to actually touch the ground from the trees. Forest floor – Mahadayi Valley, Karnataka.
Because of the ample solar energy, tropical rainforests are usually warm year round with temperatures from about 72-93F (22-34C), although forests at higher elevations, especially cloud forests, may be significantly cooler. The temperature may fluctuate during the year, but in some equatorial forests the average may vary as little as 0.5F (0.3C) throughout the year. Temperatures are generally moderated by cloud cover and high humidity.
 
PRECIPITATION

An important characteristic of rainforests is apparent in their name. Rainforests lie in the intertropical convergence zone where intense solar energy produces a convection zone of rising air that loses its moisture through frequent rainstorms. Rainforests are subject to heavy rainfall, at least 80 inches (2,000 mm), and in some areas over 430 inches (10,920 mm) of rain each year. In equatorial regions, rainfall may be year round without apparent “wet” or “dry” seasons, although many forests do have seasonal rains. Even in seasonal forests, the period between rains is usually not long enough for the leaf litter to dry out completely. During the parts of the year when less rain falls, the constant cloud cover is enough to keep the air moist and prevent plants from drying out. Some neotropical rainforests rarely go a month during the year without at least 6″ of rain. The stable climate, with evenly spread rainfall and warmth, allows most rainforest trees to be evergreen—keeping their leaves all year and never dropping all their leaves in any one season. Forests further from the equator, like those of India, Thailand, Sri Lanka, and Central America, where rainy seasons are more pronounced, can only be considered “semi-evergreen” since some species of trees may shed all of their leaves at the beginning of the dry season. Annual rainfall is spread evenly enough to allow heavy growth of broad-leafed evergreen trees, or at least semi-evergreen trees. The moisture of the rainforest from rainfall, constant cloud cover, and transpiration (water loss through leaves), creates intense local humidity. Each canopy tree transpires some 200 gallons (760 liters) of water annually, translating to roughly 20,000 gallons (76,000 L) of water transpired into the atmosphere for every acre of canopy trees. Large rainforests (and their humidity) contribute to the formation of rain clouds, and generate as much as 75 percent of their own rain.
The Amazon rainforest is responsible for creating as much as 50 percent of its own precipitation. Deforestation and climate change may be affecting the water cycle in tropical rainforests. Since the mid-1990s, rainforests around the world have experienced periods of severe drought, including southeast Asia in 1997 and 2005 and the Amazon in 2005. Dry conditions, combined with degradation from logging and agricultural conversion, make forests more vulnerable to wildfire.

Rainforests Waters
Tropical rainforests have some of the largest rivers in the world, like the Amazon, Madeira, Mekong, Brahmaputra, Negro, Orinoco, and Zaire (Congo), because of the tremendous amount of precipitation their watersheds receive. These mega-rivers are fed by countless smaller tributaries, streams, and creeks. For example, the Amazon alone has some 1,100 tributaries, 17 of which are over 1,000 miles long. Although large tropical rivers are fairly uniform in appearance and water composition, their tributaries vary greatly. Many tropical rivers and streams have extreme high and low water levels that occur at different parts of the year. In addition to rivers, rainforests have conventional, free-standing lakes and so-called oxbow lakes, formed when a river changes course. These lakes are home to species adapted to the quiet, stagnant conditions. Tropical waters, whether they be giant rivers, streams, or oxbow lakes, are almost as rich in animal species as the rainforests that surround them. But they, too, are increasingly threatened by human activities, including pollution, siltation resulting from deforestation, hydroelectric projects, and over-harvesting of resident species.

Forest – the mother of rivers

There is an umbilical connection between healthy forests and water regimes. Forests are nurseries and cisterns for our life giving rivers. Forest areas give birth to all the major and minor rivers. Most of the rivers spring from some unknown forests. Because of the slope the rain water cannot stay to soak into the earth, it flows downhill rapidly taking some of the earth with it This run-off on the hillsides will only be halted, and water will percolate into the earth where there is a good tree cover. In fact a forest “traps” rainwater and channels it into underground streams.
 
World’s Largest Pharmacy

Medicinal plants and herbs which are in great demand by Pharmaceutical MNCs e.g. Mappia foetida used for the treatment of ovarian colon cancers. The tree is the richest source of Camptothetician (CPT) used in the treatment of these cancers.

Tropical rainforests are called “the world’s largest pharmacy” because of the large amount of natural medicines discovered in rainforests that are derived from rainforest plants. For example, rain forests contain the basic ingredients of hormonal contraception methods, cocaine, stimulants, and tranquilizing drugs. Curare (a paralyzing drug) and quinine (a malaria cure) are also found there.
CONSEQUENCES OF DEFORESTATION

Rainforests around the world still continue to fall. Does it really make a difference? Why should anyone care if some plants, animals, mushrooms, and microorganisms perish? Rainforests are often hot and humid, difficult to reach, insect-ridden, and have elusive wildlife.
Actually the concern should not be about losing a few plants and animals; mankind stands to lose much more. By destroying the tropical forests, we risk our own quality of life, gamble with the stability of climate and local weather, threaten the existence of other species, and undermine the valuable services provided by biological diversity. While in most areas environmental degradation has yet to reach a crisis level where entire systems are collapsing, it is important to examine some of the effects of existing environmental impoverishment and to forecast some of the potential repercussions of forest loss. Continuing loss of natural systems could make human activities increasingly vulnerable to ecological surprises in the future. The most immediate impact of deforestation occurs at the local level with the loss of ecological services provided by tropical rainforests and related ecosystems. Such habitats afford humans valuable services such as erosion prevention, flood control, water treatment, fisheries protection, and pollination—functions that are particularly important to the world’s poorest people, who rely on natural resources for their everyday survival. Forest loss also reduces the availability of renewable resources like timber, medicinal plants, nuts and fruit, and game. Over the longer term, deforestation of tropical rainforests can have a broader impact, affecting global climate and biodiversity. These changes are more difficult to observe and forecast from local effects, since they take place over a longer time scale and can be difficult to measure.
Deforestation and the Global Carbon Cycle
Carbon dioxide ( CO2) is the major gas involved in the greenhouse effect, which causes global warming. All the things that produce CO2 (like car burning gas) and the things that consume Co2 (growing plants) are involved in the “global carbon cycle”. Tropical forests hold an immense amount of carbon, which joins with oxygen to form CO2. The plants and soil of tropical forests hold 460-575 billion metric tons of carbon worldwide. Each acre of tropical forest stores about 180 metric tons of carbon.
Deforestation increases the amount of CO2 and other trace gases in the atmosphere. When a forest is cut and replaced by cropland and pastures, the carbon that was stored in the tree trunks (wood is about 50% carbon) joins with oxygen and is released into the atmosphere as Co2.The loss of forests has a great effect on the global carbon cycle. From 1850 to 1990, deforestation worldwide (including that in the United States) released 122 billion metric tons of carbon into the atmosphere, with the current rate being 1.6 billion metric tons per year. In comparison all the fossil fuels (coal, oil and gas) burned during a year release about 6 billion tons per year.Releasing CO2 into the atmosphere increases the greenhouse effect, and may raise global temperature. The role of fossil fuels burned by cars and industry is well known, but tropical deforestation releases about 25% of the amount released by fossil fuel burning. Tropical deforestation, therefore, contributes a significant part of the increasing CO2 in the atmosphere.
Today tropical rainforests are disappearing from the face of the globe. Despite growing international concern, rainforests continue to be destroyed at a pace exceeding 80,000 acres (32,000 hectares) per day. World rainforest cover now stands at around 2.5 million square miles (6 million square kilometers), an area about the size of the contiguous 48 United States or Australia and representing around 5 percent of the world’s land surface. Much of this remaining area has been impacted by human activities and no longer retains its full original biodiversity.
 
The Rainforests of India
The rainforests in India are the centres of species richness and endemism and due to this has the status of being one of the 12 mega-biodiversity countries in the world. Even the two hotspots in India, the Western Ghats and the Eastern Himalayas, owe their status due to the presence of rainforests therein. These forests form very important catchments areas for major river systems, maintain soil and water fertility not only in the immediate vicinity but also hundreds of kilometers away, harbours rich indigenous culture with long traditions of sustainable use of traditional knowledge systems especially on medicines and wild relatives of cultivate crops. It is to these rainforests that more than 80% of the endemic flora and fauna of India are confined. Being the most complex ecosystem, the rain forests are living laboratories in which complex ecological, biological and evolutionary processes that have shaped the Earth.

Bamboo brakes, Muthodi, Karnataka

 
Tropical forest cover in India has been reduced to two major areas: the coastal hills of the Western Ghats (about 55,000 square miles or 135,000 sq. km) and 14,000 square miles (34,500 sq. km) in Northeastern India. Very little of India’s forest cover is considered pristine. 22.8% —or about 67,701,000 hectares—of India is forested. Change in Forest Cover: Between 1990 and 2000, India gained an average of 361,500 hectares of forest per year. The amounts to an average annual reforestation rate of 0.57%. Between 2000 and 2005, the rate of forest change decreased by 92.3% to 0.04% per annum. In total, between 1990 and 2005, India gained 5.9% of its forest cover, or around 3,762,000 hectares. Measuring the total rate of habitat conversion (defined as change in forest area plus change in woodland area minus net plantation expansion) for the 1990-2005 interval, India gained 1.0% of its forest and woodland habitat.Biodiversity and Protected Areas: India has some 2356 known species of amphibians, birds, mammals and reptiles according to figures from the World Conservation Monitoring Centre. Of these, 18.4% are endemic, meaning they exist in no other country, and 10.8% are threatened. India is home to at least 18664 species of vascular plants, of which 26.8% are endemic. 4.9% of India is protected under IUCN categories I-V.

Rainforests of the Western Ghats
The Western Ghats hill range in India contains spectacular landscapes and an incredible array of wild species, many found nowhere else in the world. One among the world’s 34 most biologically diverse “hotspots”, the region has representation of a wide variety of natural ecosystems from grasslands and dry forests to rainforests, rivers, and streams, threatened by a multitude of human activities such as industrialisation, agriculture, grazing, hunting, deforestation, fragmentation, and degradation. Today, rainforests in the Western Ghats occur largely as fragments within a landscape matrix dominated by commercial plantations of tea, coffee, and other cash crops. With an annual deforestation rate of 1.2%, the southern Western Ghats is losing about 500 square kilometres of forest every year. NCF’s programme focuses on human impacts on wild species and habitats, biological surveys, human-wildlife conflict research and mitigation, and restoration to turn the tide of destruction towards conservation.

Forests of the western slopes of the Western Ghats, Konkan

The northern portion of the range is generally drier than the southern portion, and at lower elevations makes up the North Western Ghats moist deciduous forests ecoregion, with mostly deciduous forests made up predominantly of teak. Above 1,000 meters elevation are the cooler and wetter North Western Ghats montane rain forests, whose evergreen forests are characterized by trees of family Lauraceae.The evergreen Wayanad forests of Kerala mark the transition zone between the northern and southern ecoregions of the Western Ghats. The southern ecoregions are generally wetter and more species-rich. At lower elevations are the South Western Ghats moist deciduous forests, with Cullenia the characteristic tree genus, accompanied by teak, dipterocarps, and other trees. The moist forests transition to the drier South Deccan Plateau dry deciduous forests, which lie in its rain shadow to the east.
 

Clear felling, Mahadayi Valley, Karnataka

 
Above 1,000 meters are the South Western Ghats montane rain forests, also cooler and wetter than the surrounding lowland forests, and dominated by evergreen trees, although some montane grasslands and stunted forests can be found at the highest elevations. The South Western Ghats montane rain forests are the most species-rich ecoregion in peninsular India; eighty percent of the flowering plant species of the entire Western Ghats range are found in this ecoregion.

Tropical Montane – Bedthi River Valley, Karnataka

The animal life of the Indian peninsular region is characterised by the absence of many of the Indo-Malay species which are so abundant in the hill forests of the Himalayas. It is the home of the true Indian fauna of which the spotted deer, the nilgai, the blackbuck, the four-horned antelope, and the sloth bear are typical representatives. They are found no where else. Other species like the gaur, the sambar and the muntjac (barking deer) occur both in India and Malay countries. The Western Ghats, in sharp contrast to the adjoining dry zone of the Deccan present a region of great humidity and heavy rainfall. The forests covering the western slopes are at times very dense and composed of lofty trees, festooned with perennial creepers. Bamboos form a luxuriant undergrowth. In parts of the range the forests are more open and the banks of clear streams running through them are covered with spice and betel groves.
The Nilgiris, an offshoot of the Western Ghats, rise precipitously to form extensive grassy downs and tablelands seamed with densely forested gorges or Sholas. They are composed of evergreen trees with dense undergrowth.

1. Malabar Giant Squirrel 2. Lion tailed Macaque

 
Among the species limited to these forests are the Nilgiri langur, the Lion-tailed macaque, the Nilgiri brown mongoose and the striped necked mongoose, the Malabar civet, and the spiny mouse. In the higher levels of the Nilgiris and the Anaimalais are found such characteristically Himalayan animals as the tahr, the pine marten and the European otter.
 

Endemic species of the Western Ghats

One hundred and twenty species of mammals are known from the Western Ghats of which fourteen species are endemic (found only in that area).
 
The mammalian fauna of the Western Ghats is dominated by insectivores (11 species), bats (41 species) and rodents (27 species including porcupine). Few studies have, however, paid attention to the community structure and organisation of these small mammals in the Western Ghats, although there have been attempts to review our understanding of the status and ecology of smaller cats and lesser carnivores.
 
Rainforests of the Northeast India
 
The Northeast India lying between 22-30 degree N latitude and 89-97 degree E longitude, and sprawling over 2,62,379 sq.km., Northeast India represents the transition zone between the Indian, Indo-Malayan and Indo-Chinese biogeographic regions and a meeting place of the Himalayan Mountains and Peninsular India. It was the part of the northward migrating ‘Deccan Peninsula’ that first touched the Asian landmass after the break up of Gondwanaland in the early Tertiary Period. Northeast India is thus the geographical ‘gateway’ for much of India’s flora and fauna, and as a consequence, the region is one of the richest in biological values. It is in this lowland-highland transition zone that the highest diversity of biomes or ecological communities can be found, and species diversities within these communities are also extremely high.
 
Northeast India is blessed with a wide range of physiography and ecoclimatic conditions. The State of Assam has extensive flood plains, while Khangchendzonga in Sikkim stands 8586 m. tall. Cherrapunjee in the State of Meghalaya holds the record for the highest rainfall in a single month (9,300 mm) as well as the most in a year (26,461 mm) in India, while the nearby Mawsynram has the world’s highest average rainfall (11,873 mm). The forests in the region are extremely diverse in structure and composition and combine tropical and temperate forest types, alpine meadows and cold deserts. There are regions, for example, in the State of Sikkim, where the faunal assemblages also change rapidly from tropical to subtropical, temperate, alpine and finally to cold desert forms.
 
After the Andaman and Nicobar Islands and the Western Ghats, Northeast India forms the main region of tropical forests in India, especially the species-rich tropical rain forests. The tropical semi-evergreen and moist deciduous forests in the lowlands of this region extend south and west into the subcontinent, and east into Southern China and Southeast Asia. The subtropical forests of the region follow the foothills of the Himalaya to the west; also extend into Southeast China in the east. Himalayan temperate and subalpine zone forests extend from northern Pakistan and adjacent Afghanistan through Northeast India to Southwest China. Each of the eight States of the region, namely Arunachal Pradesh, Assam, Meghalaya, Manipur, Mizoram, Nagaland, Sikkim and Tripura, boast of several endemics in flora as well as fauna. This region represents an important part of the Indo-Myanmar biodiversity hotspot.
 
1. Dooars forests, North Bengal 2. Golden Langur
 
The primary vegetation in extensive areas of the Northeast India has been disturbed and modified and in some places destroyed by seismic activities, frequent landslides and resultant soil erosion. While these natural causes have contributed only marginally to the change in vegetation type, it is the activity of Man that has led to the irreversible transformation in the landscapes and has resulted in colossal loss of biodiversity in the entire region. Human influences have pushed many species to the brink of extinction and have caused havoc to natural fragile ecosystems. Such devastations to natural ecosystems are witnessed almost everywhere in the region and is a cause of great concern.

 
1. Slow Loris 2. Reticulated Python

Northeast India has 64% of the total geographical area under forest cover and it is often quoted that it continues to be a forest surplus region. However, the forest cover is rapidly disappearing from the entire region. There has been a decrease of about 1800 sq.km. in the forest cover between 1991 and 1999. More worrisome still is the fact that the quality of the forest is also deteriorating, with the dense forests (canopy closure of 40% or more) becoming degraded into open forest or scrub. Though there is a succession of several edaphic formations, a vast area of land has already been transformed into barren and unproductive wastelands. This being the case, the statistics of ‘more than 64 % of the total geographic area in this region under forest cover’ could be misleading. For example, though the forest cover in Manipur extends to 78% of the total geographic area, only 22% of forest area is under dense forest cover and the rest has been converted to open forests.
 
 
Except in the Brahmaputra and Barak valleys of Assam where substantial areas are under agriculture, little of the land is available for settled cultivation. Hence, shifting agriculture or slash-and-burn agriculture is the major land use in Northeast India and extends over 1.73 million ha. Different agencies have come up with different figures concerning the total area under shifting cultivation (jhum) in the region. What is not disputable is that with an ever shortening jhum cycle, the other human influences have caused environmental degradation with disastrous consequences.The forests of Assam once acted as a sponge, absorbing the tremendous impact of the monsoons. The natural drainage of the vast northeastern Himalaya is channelled through Assam and with the loss of thick forest cover, Brahmaputra, one of the largest and fastest flowing rivers of the subcontinent is creating havoc in the State. Floods that have devastating effects are now common to Northeast India and protecting the forests is a difficult problem.
 
 
The Rainforests of the Andamans & Nicobar Islands

 
The Andamans and Nicobar Islands have tropical evergreen rain forests and tropical semi-evergreen rainforests as well as tropical monsoon moist monsoon forests.
 
There are 572 islands in the territory, of which only approximately 38 are permanently inhabited. Most of the islands (about 550) are in the Andamans group, 26 of which are inhabited. The smaller Nicobars comprise some 22 main islands (10 inhabited). The Andamans and Nicobars are separated by a channel (the Ten Degree Channel) some 150 km wide.The total area of the Andaman Islands is some 6,408 km²; that of the Nicobar Islands approximately 1,841 km².

 
Aerial view -Andamans & Nicobar Islands

Andaman & Nicobar Islands are blessed with a unique tropical rainforest canopy, made of a mixed flora with elements from Indian, Myanmarese, Malaysian and endemic floral strains. So far, about 2,200 varieties of plants have been recorded, out of which 200 are endemic and 1,300 do not occur in mainland India.The South Andaman forests have a profuse growth of epiphytic vegetation, mostly ferns and orchids. The Middle Andamans harbours mostly moist deciduous forests. North Andamans is characterised by the wet evergreen type, with plenty of woody climbers. The north Nicobar Islands (including Car Nicobar and Battimalv) are marked by the complete absence of evergreen forests, while such forests form the dominant vegetation in the central and southern islands of the Nicobar group. Grasslands occur only in the Nicobars, and while deciduous forests are common in the Andamans, they are almost absent in the Nicobars. The present forest coverage is claimed to be 86.2% of the total land area.

 
 
 
References: Wikipedia, Mongabay,com, Animal corner.com, The Western Ghats by Mohan Pai, Nature Conservation Foundation, Biodiversity of Northeast India an Overview -V.Ramakantha, A.K.Gupta, Ajith Kumar
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Global Warming & India

An article by Mohan Pai

(This article was written by me for a publisher in Goa more then two years ago. It’s still very relevant and I thought I will reproduce it here for my blog readers.)
The Earth is heating up – and fast.
 
Cause for alarm ?

 

INTRODUCTION
Global Warming issue is now really hotting up. The ‘Catastrophe’ that the world and humanity now faced with is of such mammoth proportions and unprecedented that humanity’s very survival is in question. Sceptics thought that it was a case of “crying wolf”. But the wolf now seems to be at our very doorstep.
11 of the last 12 years have been warmest on record.Intergovernmental Panel on Climate Change issued the summary of its fourth report in Paris on May 2 of this year. It is quite categorical about the fact that global warming is mainly due to anthropological (human-made) causes. Mainly the emission of greenhouse gases into the atmosphere due to human influence. For decades, this has been a topic of conjecture but no more. All the signs are now clearly there – the melting ice of the glaciers, increase in the number of heat waves, increased intensity of tropical storms, changing weather patterns and rising sea levels.
Worldwide, very little is being done to control or reduce the emissions of greenhouse gases. U.S.A. which is the largest emitter (25%) of greenhouse gases is not even a signatory to Kyoto protocol that is formed to control the greenhouse gases emissions. Deforestation, a major contributor to greenhouse gases emission, continues unabated in Brazil and Indonesia releasing billions of tons of Co2 into the earth’s atmosphere.
For India, the reality lies in some stark occurrences like farmer suicides or disappearance of two islands in the Sunderbans due to rising water displacing 6,000 people. Also the fact that the Himalayan glaciers are melting fast and some very clear signs of rise in sea levels.
For Goa, implications of global warming will be truly horrendous. Some predictions give the year 2020 when India’s shorelines will be inundated with one-metre rise in sea level. The entire West Coast will be devastated and Goa will go. One estimate puts the loss of property and assets in Goa at Rs. 5,000 billion. The three metros – Mumbai, Chennai and Kolkota are also expected to be submerged along with most of the coastal settlements of India.
It could happen by 2030 0r 2070 but, the probability is very high. The issue is of a global-scale and requires global-scale action. About time everybody woke up.
Are we going to shut the barn door after the horse has bolted ?
Mohan Pai
Bangalore
December 10. 2006
WHAT IS GLOBAL WARMING ?

 The earth’s average temperature is on the rise. For decades this has been a subject of conjecture, but no more. The climate change is with us. According to Climatologists, 2005 was the warmest year in a century, with 1998, 2002, 2003 and 2004 next in line. The visible effects can now be felt in the form of melting glaciers in Greenland, Alaska, the Alps, the Himalayas and the polar regions of the Arctic and the Antarctic. Permafrost (permanently frozen soil) in Canada, Alaska and Siberia is melting at an alarming rate. Sea levels are rising. Hurricanes are becoming more numerous and more intense. According to some, humanity is sitting on a volatile time bomb – one that could send the entire planet into a tailspin of epic destruction, with detonation not far in the future. But is this a realistic scenario ?

This diagram predicts the global temperatures for the period 2070-2100 vs 1960-1990 average temperatures.

One of the most hotly debated topics on the earth today is the subject of climate change. The term ‘global warming’ which in common usage refers to recent warming and implies a human influence. According to the National Academy of Sciences, the average surface temperature of the earth went up by one degree Fahrenheit during the past hundred years, with accelerated warming occurring within the past 20 years and the decade of 1995-2005 being the warmest during the last hundred years
It is such an intricate and complex subject that even today’s super computers have been inadequate for correct predictions. Since 1950 there have been indications of rise in global average temperatures and in the seventies and the eighties of the last century the phenomena started becoming more prominent. Considering the seriousness of the threat, the United Nations set up the Intergovernmental Panel on the Climate Change (IPCC) in the year 1988. With hundreds of scientists and specialists working on the project, the Panel has built a massive data base and so far issued four reports. The fourth report was issued in the month of February, 2007 in which the IPCC has sounded the bleakest warning on Climate Change that human activity is the main driver, “very likely” causing most of the rise in global temperatures since 1950. The following graph indicates the probability of the phenomenon and the warning signs that are becoming apparent.

 

WARNING SIGNS
*Eleven of the last 12 years are among the warmest on record
*Oceans have warmed down to 3,000 metres
*Mountain glaciers and snow cover have declined
*Satellites have seen an acceleration in sea level rise
*More intense and longer droughts have been observed
*Arctic ice cover is shrinking in depth and in extent

 

KEY FINDINGS
It is very likely that human activities are causing global warming.
 
Possible temperature rise by the end of the century ranges between 1.1C and 6.4C (2-11.5F)
Sea levels are likely to rise by 28-43cm
Arctic summer sea ice is likely to disappear in second half of century
It is very likely that parts of the world will see an increase in the number of heat waves
Climate change is likely to lead to increased intensity of tropical storms
75-250 million people across Africa could face water shortages by 2020
Crop yields could increase by 20% in East and Southeast Asia, but decrease by up to 30% in Central and South Asia Agriculture fed by rainfall could drop by 50% in some African countries by 2020
20-30% of all plant and animal species at increased risk of extinction if temperatures rise between 1.5-2.5C
Glaciers and snow cover expected to decline, reducing water availability in countries supplied by melt water
 
Big questions remain about the speed and extent of some impending changes, both because of uncertainty about future population and pollution trends and the complex relationships of the emission of the greenhouse gases, clouds, dusty kinds of pollution, the oceans and the earth’s veneer of life, which both emits and soaks up carbon dioxide and other such gases.
 
The world’s primary international agreement on combating global warming is the Kyoto Protocol, an amendment to the United Nations Framework Convention on Climate Change (UNFCCC), negotiated in 1997. The Protocol now covers more than 160 countries globally and over 55% of global greenhouse gas emissions. The United States, the world’s largest greenhouse gas emitter (25% of the total world emission); Australia; and Kazakhstan have refused to ratify the treaty. China and India, two other large emitters, have ratified the treaty but, as developing countries, are exempt from its provisions. This treaty expires in 2012, and international talks began in May 2007 on a future treaty to succeed the current one.

 

These graphs show actual data and 2001 Ipcc predictions for carbon dioxide concentrations in the atmoshere in parts per million (top graph): changes in temperature relative to 1990 temperatures (middle graph) and changes in sea-levels relative to 1990 levels (bottom graph).
GREENHOUSE EFFECT
 
The earth’s climate and weather is driven by energy from the sun. The greenhouse effect is the rise in temperatures that the earth experiences because certain gases in the atmosphere (water vapour, carbon dioxide, nitrous oxide, methane and ozone, for example) trap energy from the sun. The energy heats the earth, which in turn radiates that heat back into space. But, much of this heat is retained by the greenhouse gases in the earth’s atmosphere. Without these gases, heat would escape back into space and the earth’s average temperature would be about 60 degrees Fahrenheit colder and obviously, this would not be an environment conducive for life and the earth would be inhabitable.

But the problem arises when the quantum of greenhouse gases increases to a higher level and the greenhouse effect becomes stronger increasing the heat in the atmosphere and making the earth warmer than usual. Even a little extra warming may give rise to serious problems for life on earth – humans, plants and animals.

 

The greenhouse effect was discovered by Joseph Fourier in 1824 and was first investigated by Svante Arrhenius in 1896. On earth, the major greenhouse gases are water vapour, which causes about 36-70% of the greenhouse effect (not including the clouds), carbon dioxide (Co2), which causes 9-26%, methane (Ch4) which causes 4-9% and ozone, which causes 3-7%. The atmospheric concentrations of Co2 and Ch4 have increased by 31% and 149% respectively above pre-industrial level since 1750. These levels are considerably higher than at any time during the last 6,50,000 years, the period for which reliable data has been extracted from ice cores.
About three-quarters of the anthropogenic (man-made) emissions of Co2 to the atmosphere during the past twenty years are due to fossil fuel (petrol, diesel, coal, etc.) burning. The rest of the anthropogenic emissions are predominantly due to land-use change, especially deforestation.

 

If current trends continue, we will raise atmospheric Co2 concentrations to double pre-industrial levels during this century. That will probably be enough to raise global temperatures by around 2 to 5 degrees Centigrade. Some warming is certain, but the degree will be determined by feedbacks involving melting ice, the oceans, water vapour, clouds and changes in vegetation.
The main causes for the increased greenhouse effect are the burning of the Fossil Fuels and Deforestation

 Fossil Fuels and the Global Carbon Cycle

Huge amounts of carbon have been captured by plants and buried in the ground in the form of coal, oil, natural gas called fossil fuels. These fuels have accumulated over the course of millions of years. With the advent of Industrial Revolution, mankind began extracting and burning earth’s vast reserves of these fuels. This released millions of tons of carbon, in the form of Co2 in the atmosphere, thus increasing the levels of greenhouse gases that are now affecting the earth’s temperature. Since then, atmospheric concentrations of Co2 have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide have risen about 15%. These increases have enhanced the heat trapping capability of the earth’s atmosphere, and will continue to do so for years to come.
As per the IPCC report : “Annual fossil fuel carbon dioxide emissions increased from an average of 6.4 GtC (billion tonnes of carbon) in the 1990s to 7.2 GtC in 2000-2005.”

 

Deforestation and the Global Carbon Cycle

 Carbon dioxide ( CO2) is the major gas involved in the greenhouse effect, which causes global warming. All the things that produce CO2 (like car burning gas) and the things that consume Co2 (growing plants) are involved in the “global carbon cycle”.
Tropical forests hold an immense amount of carbon, which joins with oxygen to form CO2. The plants and soil of tropical forests hold 460-575 billion metric tons of carbon worldwide. Each acre of tropical forest stores about 180 metric tons of carbon.
Deforestation increases the amount of CO2 and other trace gases in the atmosphere. When a forest is cut and replaced by cropland and pastures, the carbon that was stored in the tree trunks (wood is about 50% carbon) joins with oxygen and is released into the atmosphere as CO2.
The loss of forests has a great effect on the global carbon cycle. From 1850 to 1990, deforestation worldwide (including that in the United States) released 122 billion metric tons of carbon into the atmosphere, with the current rate being 1.6 billion metric tons per year. In comparison all the fossil fuels (coal, oil and gas) burned during a year release about 6 billion tons per year.
Releasing CO2 into the atmosphere increases the greenhouse effect, and may raise global temperature. The role of fossil fuels burned by cars and industry is well known, but tropical deforestation releases about 25% of the amount released by fossil fuel burning. Tropical deforestation, therefore, contributes a significant part of the increasing CO2 in the atmosphere.

 


GLOBAL TEMPERATURE PROJECTIONS

 

The Intergovernmental Panel on Climate Change predicts that temperatures are most likely to rise by 1.8 C – 4C by 2001. But the possible range is much greater; 1.1C – 6.4C. The maps above show how a range of three different scenarios will affect different parts of the world.
 
The emissions scenarios,B1, A1B, A2 used to create the maps above, are based on a range of detailed economic and technological data. These versions of the future consider different population increases, fossil and alternative fuel use, and consequent Co2 increases.
Carbon dioxide is the main greenhouse gas, its rise since the industrial revolution is clear. Burning coal, using oil and deforestation all place Co2 into atmosphere.
The other two main greenhouse gases are methane and nitrous oxide. Both gases have a much smaller presence in the atmosphere than Co2 but are much stronger greenhouse gases; methane has over 20 times the effect of Co2, whileNitrous oxide is nearly 300 times stronger.
What is the evidence of warming?
Temperature records go back to the late 19th Century and show that the global average temperature increased by about 0.6C in the 20th Century. Sea levels have risen 10-20cm – thought to be caused mainly by the expansion of warming oceans. Most glaciers in temperate regions of the world and along the Antarctic Peninsula are in retreat; and records show Arctic sea-ice has thinned by 40% in recent decades in summer and autumn. There are anomalies however – parts of the Antarctic appear to be getting colder, and there are discrepancies between trends in surface temperatures and those in the troposphere (the lower portion of the atmosphere).
 

How much will temperatures rise?
 
If nothing is done to reduce emissions, current climate models predict a global temperature increase of 1.1-6.4C by 2100. Even if we cut greenhouse gas emissions dramatically now, scientists say the effects would continue because parts of the climate system, particularly large bodies of water and ice, can take hundreds of years to respond to changes in temperature. It also takes greenhouse gases in the atmosphere decades to break down. It is possible that we have already irrevocably committed the Greenland ice sheet to melting, which would cause an estimated 7m rise in sea level. There are also indications that the west Antarctic ice sheet may have begun to melt, though scientists caution further research is necessary.
How Will the Weather Change ?
Globally, we can expect more extreme weather events, with heat waves becoming hotter and more frequent. Scientists predict more rainfall overall, but say the risk of drought in inland areas during hot summers will increase. More flooding is expected from storms and rising sea levels. There are, however, likely to be very strong regional variations in these patterns, and these are difficult to predict.
What will the effects be?
The potential impact is huge, with predicted freshwater shortages, sweeping changes in food production conditions, and increases in deaths from floods, storms, heat waves and droughts. Poorer countries, which are least equipped to deal with rapid change, will suffer most.
Plant and animal extinctions are predicted as habitats change faster than species can adapt, and the World Health Organization has warned that the health of millions could be threatened by increases in malaria, water-borne disease and malnutrition. The precise relationship between concentrations of carbon dioxide (and other greenhouse gases) and temperature rise is not known, which is one reason why there is such uncertainty in projections of temperature increase. Global warming will cause some changes which will speed up further warming, such as the release of large quantities of the greenhouse gas methane as permafrost melts. Other factors may mitigate warming; it is possible that plants may take more CO2 from the atmosphere as their growth speeds up in warmer conditions, though this remains in doubt. Scientists are not sure how the complex balance between these positive and negative feedback effects will play out.
 

What don’t we know?
We don’t know exactly what proportion of the observed warming is caused by human activities or what the knock-on effects of the warming will be.

What about the sceptics?

Global warming “sceptics” fall into three broad camps: those who maintain temperatures are not rising those who accept the climate is changing but suspect it is largely down to natural variation those who accept the theory of human-induced warming but say it is not worth tackling as other global problems are more pressing.Nevertheless, there is a growing scientific consensus that, even on top of the natural variability of the climate, something out of the ordinary is happening and humans are to blame.
 

THE GREAT MELTDOWN
The Arctic, one of the most forbidding environments in the world, is home to the polar bear. During the summer, these animals roam this region on large chunks of floating ice, drifting for hundreds of miles. This is how they find mates and hunt for seals, fattening themselves to prepare for the severe winter. If these palettes of ice did not exist, the polar bear would not survive.
Within the past three decades, more than one million square miles of sea ice—an area the size of Norway, Denmark and Sweden combined – has vanished. Presently, ice at the southern Arctic region of the polar bear’s range is melting about three weeks sooner than has previously been the case. This affords the bears less time to hunt, eat and store fat. Due to this early melting, the Hudson Bay polar bear population has declined by 14% during the past ten years.Some climate models predict that 50 to 60% of this vital summer sea ice will disappear by the end of this century; others predict that by just 2070, the Arctic will be completely ice-free in the summer. If this does indeed occur, the world’s largest bear could become extinct.

Meanwhile, glaciers in Greenland are receding at alarming rates. Within the last five years, those along the eastern and western coasts have receded about 300 miles each. Although a total meltdown is highly unlikely, with more than one-fifth of the population living less than two feet above sea level, not much melting is required to cause significant damage.Permafrost in the Arctic region is diminishing as well. According to a report in the Geophysical Research Letters, it could shrink by 60 to 90% by 2100. A National Oceanic and Atmospheric Administration climate scientist states that this will increase freshwater runoff into the Arctic Ocean by 28%, lead to the release of large quantities of greenhouse gases from the soil, and upset ecosystems within a wide area.

 

THE ANTARCTIC

 Huge, pristine, dramatic, unforgiving; the Antarctic is where the biggest of all global changes could begin. There is so much ice here that if it all melted, sea levels globally would rise hugely – perhaps as much as 80m. Say goodbye to London, New York, Sydney, Bangkok, Rio… in fact, the majority of the world’s major cities. But will it happen? Scientists divide the Antarctic into three zones: the east and west Antarctic ice sheets; and the Peninsula, the tongue of land which points up towards the southern tip of South America.

 . “Everybody thinks that the Antarctic is shrinking due to climate change, but the reality is much more complex,” says David Vaughan, a principal investigator at the British Antarctic Survey in Cambridge, UK. “Parts of it appear to be thickening as a result of snowfall increases. But the peninsula is thinning at an alarming rate due to warming. “The West Antarctic sheet is also thinning, and we’re not sure of the reason why.” Temperatures in the Peninsula appear to be increasing at around twice the global average – about 2C over the last 50 years. Those figures are based on measurements made by instruments at scientific stations. Earlier this year, David Vaughan’s group published research showing that the vast majority of glaciers along the Peninsula – 87% of the 244 studied – are in retreat. 

A little under 70% of the world’s Fresh water is locked up in ice

 
The ice dumped into the ocean as the glaciers retreat should not make much difference to global sea levels – perhaps a few cm. More worrying, potentially, are the vast ice sheets covering the rest of Antarctica. Making temperature measurements for the continent as a whole is difficult; it is a vast place – more than 2,000km across – there are few research stations, and temperatures vary naturally by 2-3C from year to year. But measurements indicate that in the west, melting is underway. “About one-third of the West Antarctic ice sheet is thinning,” says Dr Vaughan, “on average by about 10cm per year, but in the worst places by 3-4m per year.” The rock on which the West Antarctic ice rests is below sea level – and British Antarctic Survey researchers believe the thinning could be due to the ice sheet melting on its underside. “It may be that the ocean is warming and that’s causing the ice to melt, but there may be other reasons as well; for example, there’s lots of volcanism in that area and so that could change how much heat is delivered to the underside of the ice sheet.”

 

THE TEMPERATE ZONES

 

Glaciers snake over many of the world’s high regions – the Himalayas, the Andes, the Alps, Alaska. The recent signs are that these, like the Arctic, are feeling the impact of rising temperatures. Over the last five years, various teams have reported glaciers shrinking in Peru, Kazakhstan, Nepal and Alaska. “There is a global pattern of melting in most of the world’s mountain glaciers,” says Michael Hambrey, director of the Centre for Glaciology at Britain’s University of Aberystwyth. “There are exceptions – some glaciers are advancing – but overall the state of mountain glaciers is a dramatic shrinking since the 1970s. “Some have disappeared completely, and most could be gone by the end of this century.”

Hurricanes Increasing?
The year 2005 was a record-breaking one for Atlantic hurricanes, with the most named storms, the most hurricanes and the most Category-five hurricanes occurring—with New Orleans and the Mississippi Gulf Coast being nearly destroyed by Hurricane Katrina. In terms of barometric pressure, the Atlantic Basin also experienced its most intense hurricane ever that year, Hurricane Wilma. Some studies reveal that tropical storms around the world are intensifying, with computer models suggesting a shift toward extreme intensity. A big question on many minds is, “Does the warming of the earth have a direct effect on the strength of hurricanes?” Opinions are varied.Scientists caution that one must consider questions of climate change over decades, even centuries. A particularly rough hurricane season or two cannot be blamed on global warming.Preliminary evidence suggests that, once hurricanes form, they will be stronger if the oceans are warmer. However, much uncertainty exists about whether hurricanes and other storms will become more frequent.According to the Geophysical Fluid Dynamics Laboratory, which assesses natural climate variability, “The strongest hurricanes in the present climate may be upstaged by even more intense hurricanes over the next century as the earth’s climate is warmed by increasing levels of greenhouse gases in the atmosphere. Although we cannot say at present whether more or fewer hurricanes will occur in the future with global warming, the hurricanes that do occur near the end of the 21st century are expected to be stronger and have significantly more intense rainfall than under present day climate conditions.” This is based upon an anticipated increase of energy from higher sea surface temperatures.

 

PRECIPITATION
An increase in global temperature can cause changes in the amount os precipitation. Overall, land prcipitation has increased by 2% since 1900, however, precipitation changes have been spatially variable over the last century. While there is a general increase of about 0.5-1.0%/decade over land in northern mid-high latitudes, there is a decrease pf about 0.3%/decade in precipitation in sub-tropical latitudes during the 20th century. But, the tropics appear to be getting drier.

 

SEA LEVEL RISE
 
Rises in sea levels are going to be one of the most devastating consequences of Global Warming.Rises in sea levels are predicted by the new report, threatening low-lying areas of land around the world. As the oceans warm, their waters expand, while rising temperatures also increase the melting of the ice sheets that cover Greenland and Antarctica .Both these factors contribute to rises in sea levels. In 2001, the IPCC predicted that sea levels would rise by between 9 and 88 centimetres by 2100, relative to 1990 levels. The new report says rises could range from 18 cm to 59 cm. But predictions of sea level rise are one of the most contentious areas of the report – very recent research has suggested that rises of up to 140 cm are possible. The problem is that the understanding of how warming affects Greenland and Antarctic ice sheets remains limited, and they are predicted to be the most important contributors to change. Estimates of the straightforward melting of ice are incorporated in the IPCC report. But warming may also accelerate the movement of ice in glaciers into the ocean, perhaps by meltwater lubricating the undersides of ice streams.Susan Solomon, one of the report’s lead authors, said there was no published research that quantified this effect, and so it was not included. But she added: “If temperatures exceed 1.9°C to 4.6°C above pre-industrial temperatures, and were to be sustained for thousands of years, eventually we would expect the Greenland ice sheet to melt. That would raise sea level by 7 metres.”
 

IMPACT OF GLOBAL WARMING ON INDIA
 
Warming is an environmental catastrophe that is staring in the world’s face. India needs to take a serious view of this impending danger which will bring about disastrous consequences for India.
The amount of greenhouse gases in the atmosphere will be doubled by 2040 and more than treble by the end of the century. Most of this century is going to witness soaring temperature, erratic weather patterns with more intense monsoons, increased cyclonic activities, severe droughts and floods, melting glaciers and rise in sea levels.
The oceanic region adjoining the Indian subcontinent is likely to warm at its surface by about 1.5-2.0 Celsius by the middle of this century and by about 2.3-3.5 Celsius by the end of the century.

Red areas indicate the shoreline andareas likely to be innudated as a resultof sea level rise.

 
This indication is derived from modern simulation studies. In a discussion on this issue in the Indian parliament, Minister of State in the Ministry of Environment and Forests, Shri Namo Narain Meena said that the past observations on the mean sea level along the Indian coast show a long-term rising trend of about 1.0 mm/year. The recent data suggests a rising trend of 2.5 mm/year in the sea-level along Indian coastline.
The corresponding thermal expansion, related sea-level rise is expected to be between 15 cm and 38 cm by the middle of this century and between 46 cm and 59 cm by the end of the century.
According to a study conducted by the Ministry of Environment & Forests on the impacts of climate change on various sectors including coastal zones, in the event of one meter sea-level rise, 5764 Km2 of land in coastal areas of India is projected to lose, displacing approximately 7.1 million people along with 4200 Kms of roads by the end of the 21st century. Further the coastal areas are also vulnerable to projected increase in frequency and intensity of extreme weather events like storm surges and cyclones. In the eastern coast, the vulnerable districts include Jagatsinghpur and Kendrapara in Orissa and Nellore in Andhra Pradesh and Nagapattinam in Tamil Nadu.
Himalayan glaciers ‘melting fast’
Melting glaciers in the Himalayas could lead to water shortages for hundreds of millions of people in India, Nepal and China according to the conservation group of WWF
In a report, the WWF says India, China and Nepal could experience floods followed by droughts in coming decades. The Himalayas contain the largest store of water outside the polar ice caps, and feed seven great Asian rivers. The group says immediate action against climate change could slow the rate of melting, which is increasing annually. “Yangtze and Yellow rivers are believed to be retreating at a rate of about 10-15m (33-49ft) each year.
 
Himalayan glaciers ‘melting fast’
 
“The rapid melting of Himalayan glaciers will first increase the volume of water in rivers, causing widespread flooding,” said Jennifer Morgan, director of the WWF’s Global Climate Change Programme. “But in a few decades this situation will change and the water level in rivers will decline, meaning massive eco and environmental problems for people in western China, Nepal and northern India.”
 

‘Catastrophe’


The glaciers, which regulate the water supply to the Ganges, Indus, Brahmaputra, Mekong, Thanlwin, Yangtze and Yellow rivers are believed to be retreating at a rate of about 10-15m (33-49ft) each year.
 
Hundreds of millions of people throughout China and the Indian subcontinent – most of whom live far from the Himalayas – rely on water supplied from these rivers. Many live on flood plains highly vulnerable to raised water levels. And vast numbers of farmers rely on regular irrigation to grow their crops successfully.
A study commissioned for the WWF indicated that the temperature of the Earth could rise by two degrees Celsius above pre-industrial levels in a little over 20 years.
Allowing global temperatures to rise that far would be “truly dangerous”.Nepal, China and India are already showing signs of climate change, the WWF report claims.
Nepal’s annual average temperature has risen by 0.06 degrees Celsius, and three snow-fed rivers have shown signs of reduced flows. Water level in China’s Qinghai Plateau wetlands has affected lakes, rivers and swamps, while India’s Gangotri glacier is receding by 23m (75ft) each year.
The Gangotri glaciers, which form the major chunk of Ganga water, has been retreating at the rate of 34 metre every year. It is now quite apparent that the melting glaciers are threatening the volumetric flow rate of Ganga, Brahmaputra and Yamuna which will ultimately affect the crop yield and drinking water supply.
While the sea level rise is going to affect the entire shoreline of India, a very large area of the Ganges delta will be totally submerged affecting millions. There are indication of sea level rise. Two islands in the Sunderbans area have already vanished from the map. 6,000 people had to be relocated here because there land is under water.
As the waters rise, it is expected that the entire delta region, home to the legendary Bengal tiger, will be submerged.
 

 
Scientists have already warned that global warming will reduce crop yields, spread diseases and cause loss of biodiversity and will also pose economic risks to water supplies, food production, electricity, road and rail infrastructure and coastal livelihood.
 
India’s agriculture depends largely on the monsoons and with rainfall pattern changing, western and central areas of India could have up to 15 more dry days annually while the Northeast is predicted to have 5 to 10 more days of rain each year. Which means that the areas which are dry will become drier and wet will become wetter. There will be longer droughts in some areas which will reduce wheat and rice yield.

Farmers Suicides – Is the changing climate responsible ?


A World Bank study has claimed that climate change and farmer suicides in India are corelated. The report says that poor farmers were unable to adapt to changing climates, which forced them fall into debts. Richer farmers were not affected because they had the resources to shift to other crops that suit the changed climate pattern. According to the study, in Pennar basin of Andhra Pradesh, decrease in yield is directly related to increase in temperature.
 

Hydropower projects & greenhouse gas emission

Latest scientific estimates show that large dams in India ar responsible for about a fifth of India’s total global warming impact. The study titled, “Methane emission from Indian Large Dams” estimates the total generation of methane from India’s reservoirs could be around 45.8 million ton, more than the share of any other country in the world. These gases are produced by the rotting of the vegetation and soils flooded by reservoirs, and of the organic matter (plants, plankton, algae, etc. Large dams have been known to be emitters of greenhouse gases like methane, carbon dioxide and nitrous oxide for over a decade now.
Indian hydropower projects are already known for their serious social and environmental impact on the communities and the environment. The fact that these projects also emit global warming gases in such significant proportion should further destroy the myth.
 

Mumbai, Chennai risk floods: UN

Many of the world’s largest cities like Mumbai and Chennai on the sea coasts and at the mouths of the great rivers face a considerable danger of being flooded due to extreme climatic events as a result of global warming, says a report.
Coastal cities are increasingly at risk from seaward hazards such as sea level rise and stronger storms induced by climate change, says a recent report released by United Nations Population Fund (UNFPA).Sea level rise, especially if combined with extreme climatic events, would flood large parts of coastal cities, says ‘State of World Population, 2007’.The report adds that sea level rise would also introduce salt water into surface fresh water and aquifers, affecting cities’ water supply, and modify critical ecosystems supplying ecological services and natural resources to urban areas.
The population especially when concentrated in large urban areas within rich ecological zones can be a burden on coastal ecosystems, many of which are already under stress, it added.Pointing out that the best way to prevent such a scenario would be to avoid policies that favour coastal development, it asked for a better coastal zone management.
Talking about other dangers that big cities will face due to global warming, the report says, dry cities like Delhi will face acute water crisis.In a vicious circle, climate change will increase energy demand for air-conditioning in urban areas and contribute to the urban heat island effect through heat pollution. Heat pollution, smog and ground level ozone are not just urban phenomena; they also affect surrounding rural areas, reducing agricultural yields, increasing health risks and spawning tornadoes and thunderstorms, it said.
The report further pointed out that changes in average and extreme temperatures or in intensity and length of seasons can have significant influence on things such as economic activities (for instance, tourism), productivity of workers, use of urban space for social interactions and water distribution etc.It mentioned that drought, flooding and other consequences of climate change can also modify migration patterns between rural and urban areas or within urban areas increasing the number of ‘environmental refugees’.

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