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 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 ?
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.
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.
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.
What about the sceptics?
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 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'
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.
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.
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.
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.
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.
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.
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.
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’.