For the last many years several effects of global warming have been predicted and discussed at various levels. These effects not only include steady sea level rise, increased cyclonic activity, and changes in ambient temperature and precipitation patterns, but also economic and social life would be entirely affected.
Through my article, which also includes some of the demographic points also, from different sources including Intergovernmental Panel on Climate Change (IPCC), I am trying to bring about a summarized information about the effects and the projected effects of global warming on the subcontinent of South Asia, though it’s a global issue, and discussing about South Asia doesn’t imply that rest of the world is free of the affects.
As per the Intergovernmental Panel on Climate Change (IPCC), depending upon the scenario visualised and the scientific researches, the projected global average surface warming will result in temperature increases worldwide at the end of the 21st Century relative to the end of the 20th Century ranges from 0.6 to 4 °C.
The Projected changes in the natural and human environment
- Rise in sea level
At the end of the 20th century when the corresponding sea level rise was 0.18 which has reached to 0.59, (any rapid dynamical changes in the ice flows in future is being excluded in this figure).
The oceans on the planet are being absorbed over 90% of the increased atmospheric heat associated with emissions from human activity. According to the more recent analysis of a number of semi empirical model , it has been predicted that a sea level rise of about 1 metre by the year 2100 will happen.
The ongoing sea level rises have already submerged several low-lying islands in the Sundarbans , displacing thousands of people. Temperature rises on the Tibetan Plateau, which are causing Himalayan glaciers to retreat. It has been predicted that the historical city of Badin and Thatta, in the Sindh region of Pakistan would have been swallowed by the sea by 2025, as it is hard to believe but the sea is already encroaching 80 acres of land here, every day.
The landslides and flooding have increased in the few states of India like Assam. Ecological disasters, such as a 1998 coral bleaching event that killed off more than 70% of corals in the reef ecosystems off Lakshadweep and the Andamans, and was brought on by elevated ocean temperatures tied to global warming, are also projected to become increasingly common.
In South Asia, the first among the countries to be affected by severe climate change is Bangladesh. Its sea level, temperature and evaporation are increasing, and the changes in precipitation and cross boundary river flows are already beginning to cause drainage congestion. Already there is a noticeable reduction in fresh water availability, disturbance of morphologic processes and a higher intensity of flooding and other such disasters
More than 50% of people of India and 40% people of Pakistan work in agriculture or many others earn their living in coastal areas and depend on natural resources for their food, shelter and income. Climate Change will have a disproportionate impact on the more than 400 million people in these places. This is because so many depend on natural resources for their food, shelter and income.
The predictions of global warming are obviously not limited to only landslide and temperature increase but it would have a direct impact on GDP too. If the predictions made by IPCC come true, as a result of climate-related factors there would be a shifting growing seasons for major crops such as rice, wheat and maize, production of which could fall by 35-40%
If global temperatures rise by a only 1.5 - 2 °C, around seven million people are projected to be displaced due to, among other factors, submersion of parts of Mumbai and Chennai, whereas in Eastern India, villagers in India's North Eastern state of Meghalaya are also concerned that rising sea levels will submerge neighbouring low-lying Bangladesh, which may result in an influx of refugees into Meghalaya which has very few resources to handle such a drastic situation.
Meghalaya meaning 'Abode (Home) of the Clouds' in Hindi—is home to the towns of Cherapoonji and Mawsynram, which are known for the highest rainfall and the wettest places in the world. But scientists state that global climate change is causing these areas to experience an increasingly sparse and erratic rainfall pattern and a lengthened dry season, affecting the livelihoods of thousands of villagers who cultivate paddy and maize. Some areas are also supposed to face water shortages.
Thick haze , mist, fog and smoke, originating from burning biomass in northeastern India and air pollution from large industrial cities in northern states of India, often concentrate inside the Ganges Basin. The Prevailing westerlies carry aerosols along the southern margins of the steep-faced Tibetan Plateau to eastern India and the Bay of Bengal. Dust and black carbon, which are blown towards higher altitudes by winds at the southern faces of the Himalayas, can absorb shortwave radiation and heat the air over the Tibetan Plateau. The net atmospheric heating due to aerosol absorption causes the air to warm and convect upwards, which increases the concentration of moisture in the mid-troposphere and provides positive feedback that stimulates further heating of aerosols.
Pollution of mercury in India is shocking. The environment is being packed with approximately 70 tonnes of mercury per year by existing mercury-cell plants. One gram of mercury is sufficient to pollute a lake of surface area of around 18 - 20 acres that would harm the fish which as a result would be dangerous to consume.
- Ocean Acidification
The oceans are currently absorbing about a quarter of the carbon dioxide emitted to the atmosphere annually and are becoming more acidic as a result, leading to concerns about intensifying impacts on marine ecosystems.
As human-induced emissions of carbon dioxide (CO2) build up in the atmosphere, excess CO2 is dissolving into the oceans where it reacts with seawater to form carbonic acid, lowering ocean pH levels ("acidification") and threatening a number of marine ecosystems. Currently, the oceans absorbs about a quarter of the CO2 humans produce every year. Over the last 250 years, the oceans have absorbed 560 billion tons of CO2, increasing the acidity of surface waters by 30%. Although the average oceanic pH can vary on inter-glacial timescales, the current observed rate of change is roughly 50 times faster than known historical change. Regional factors such as coastal upwelling, changes in discharge rates from rivers and glaciers, sea ice loss, and urbanization have created “ocean acidification hotspots” where changes are occurring at even faster rates
The South Asian media can contribute their maximum to the increased awareness of climate change and related issues.
No common man is so much aware about such a hazardous impact of global warming. A qualitative analysis of some mainstream Indian newspapers and journals must strongly pursue the frame of scientific certainty in their coverage of climate change. Alongside, Indian, Pakistani and Bangladeshi media must highlight frames of energy challenge, social progress, public accountability and looming disaster. Till now, the effects of global warming, temperature increase, hazardous gases, etc are considered to limit either only to the school books or environmentalist and a common man never thinks of the danger, which is growing towards him in very next moment. A common man is concerned only with his livelihood, career growth, relationships, social identity, etc, but never about the fact that due to this universal reason, he or his coming generation may lose his life due to the effects of global warming.
People need to become aware of ills of global warming. Mere small initiatives from every individual like planting trees, right disposal of the garbage, etc may bring on a huge change to cope with the fatal affects of the global warming. This must be explained again and again. If not in one time but may be in many efforts the common man may understand the value of their small contribution.