The climate change is often described and used interchangeably with the term Global Warming. However, the National Academy of Science has defined ‘climate change’ as “growing in preferred use to `global warming’ because it helps convey that there are (other) changes in addition to rising temperatures.”
Climate change refers to any significant change in measures of climate (such as temperature, precipitation or wind) lasting for an extended period (decades or longer). The following factors are responsible for climate change:
(i) natural factors, such as changes in the suns’s intensity or slow changes in the Earth’s orbit around the sun;
(ii) natural processes within the climate system (such as changes in ocean circulation);
(iii) human activities that change the atmosphere’s composition (such as burning fossil fuels) and the land surface (deforestation, reforestation, urbanisation, desertification).
Ever since the earth came into being there has been a climate system. The climate of a place is the average weather that it experiences over a period of time. The factors that determine the climate at a location are the rainfall, sunshine, wind, humidity, and temperature.
While changes in the weather may occur suddenly, and noticeably, changes in the climate take a long time to settle in and are therefore less obvious. Throughout the earth’s history there have been changes in the climate. There have been well-marked cold and hot periods and all life forms adapted naturally to this change.
Over the last 150-200 years climate change has been taking place too rapidly and certain plant and animal species have found it hard to adapt. Human activities are said to be responsible for the speed at which this change has occurred and it is now a cause of worry to scientists.
The atmosphere surrounding the earth is made up of nitrogen (78 per cent), oxygen (21 per cent) and the remainder, 1 per cent, is made up of trace gases (called so because they are present in very small quantities) that include the greenhouse gases (GHGs) carbon dioxide, methane, ozone, water vapour, and nitrous oxide. These greenhouse gases act as a blanket and protect it from the harmful ultraviolet rays of the sun.
Fresh research by Danish Space Research Centre can possibly give a new twist to the controversy whether green house gas emissions is the major contributor for Global Warming. The Centre’s research based on climate date to 150 years shows that varying activity of the Sun is the most systematic contributor to natural climate variations. The green house emissions is just one of the many factors for Global Warming.
They can also be regarded as natural controllers of the earth’s temperature system. The Industrial Revolution in the 19th century saw the large-scale use of fossil fuels for industrial activities. These industries created jobs and over the years, people moved from rural areas to the cities. This trend is continuing even today. More and more land that was covered with vegetation has been cleared to make way for houses. This is why natural resources are being used extensively for construction, industries, transport, and consumption. Consumerism (our increasing want for material things) has increased by leaps and bounds, creating mountains of waste. Also, our population has increased to an incredible extent.
All this has contributed to a rise in greenhouse gases in the atmosphere. Fossil fuels such as oil, coal and natural gas supply most of the energy needed to run vehicles, generate electricity for industries, households, etc. The energy sector is responsible for about three-fourths of the carbon dioxide emissions, one-third of the methane emissions and a large quantity of nitrous oxide. It also produces nitrogen oxides (NOx) and carbon monoxide (CO) which are not greenhouse gases but do have an influence on the chemical cycles in the atmosphere that produce or destroy greenhouse gases.
Greenhouse Gases and their Sources
Undoubtedly carbon dioxide is the most important greenhouse gas in the atmosphere. Changes in land use pattern, deforestation, land clearing, agriculture, and other activities have all led to a rise in the emission of carbon dioxide.
Methane is another important greenhouse gas in the atmosphere. About one-fourth of all methane emissions are said to come from domesticated animals such as dairy cows, goats, pigs, buffaloes, camels, horses, and sheep.
Migration Challenge
The plausible spectre of large numbers of people migrating from coastal regions, and of entire populations abandoning small island countries due to rising sea levels makes it vitally important for the United Nations Framework Convention on Climate Change to come up with a strong adaptation strategy at its Copenhagen conference later 2009. The scale of the climate migration challenge is staggering. Experts estimate that by mid-century nearly 250 million people may come under pressure to move out because of intensifying monsoon flooding, desertification, and reduced food production.
The threat of mass migration is of acute concern to India because, for a start, Bangladesh, where millions of people live close to the sea, is extremely vulnerable. Another neighbour, the Maldives, fears it will almost entirely go under water with a not-impossible one-metre rise in sea level. So gloomy is the view from the beautiful, atoll nation that its recently elected government announced a move to create a sovereign fund to resettle its population of about 300,000 abroad.
Impacts of Climate Change
Climate change is a threat to mankind! Since the end of the 19th century the earth’s average surface temperature has increased by 0.3-0.6 °C. Over the last 40 years, the rise has been 0.2-0.3 °C. Recent years have been the warmest since 1860, the year when regular instrumental records became available.
Some important aspects of our lives can be affected through changes in weather patterns and some of these are discussed here.
Agriculture: The steadily-increasing human population has led to a rise in the demand for food. As more land comes under agricultural cultivation there will be more pressure on natural ecosystems. Climate change will affect agricultural yield directly because of alterations in temperature and rainfall, and indirectly through changes in soil quality, pests, and diseases. In particular, the yield of cereals is expected to decline in India, Africa, and the Middle East.
As the temperature rises conditions will become more favourable for pests such as grasshoppers to complete a number of reproduction cycles thereby increasing their population. In the higher latitudes (in the northern countries) agriculture will benefit with the rise in temperature as the winter season will be shorter and the growing seasons longer. This will also mean that pests that will move towards the higher latitudes as the temperatures rise. Extreme weather conditions such as high temperature, heavy rainfall, floods, droughts, etc. will also affect crop production.
Weather: A warmer climate will change rainfall and snowfall patterns, lead to increased droughts and floods, cause melting of glaciers and polar ice sheets, and result in accelerated sea- level rise. Rising warmth will lead to an increase in the level of evaporation of surface water; the air will also expand and this will increase its capacity to hold moisture. This, in turn, will affect water resources, forests, and other natural ecological systems, agriculture, power generation, infrastructure, tourism, and human health. An increase in the number of cyclones and hurricanes over the last few years has been attributed to changes in temperature.
Sea Level Rise: Coastal areas and small islands are among the most densely-populated parts of the world. They are also the most threatened because of rises in sea level that global warming may cause. The heating of oceans, and melting of glaciers and polar ice sheets, is predicted to raise the average sea level by about half a metre over the next century. Sea-level rise could have a number of physical impacts on coastal areas, including loss of land due to inundation and erosion, increased flooding, and saltwater intrusion. These could adversely affect coastal agriculture, tourism, freshwater resources, fisheries and aquaculture, human settlements, and health. Rising sea levels threaten the survival of many low-lying island nations, such as the Maldives and Marshall Islands.
Health: The weather has a direct impact on our health. If the overall climate becomes warmer, there will be an increase in health problems. It is anticipated that there will be an increase in the number of deaths due to greater frequency and severity of heat waves and other extreme weather events. The elderly, the very young and those suffering from respiratory and cardiovascular disorders will probably be affected by such weather extremes as they have lesser coping capacity. An extreme rise in the temperature will affect people living in the urban areas more than those in the rural areas.
Forests and Wildlife: Ecosystems sustain the earth’s entire storehouse of species and genetic diversity. Plants and animals in the natural environment are very sensitive to changes in climate. The ecosystems that are most likely to be affected by this change are the ones in the higher latitudes, the Tundra forests. Polar regions will feel the impact of warming more than others. Interiors of continents will experience more warming than the coastal regions.
National parks are supposed to provide a sanctuary to wildlife from the ravages of humankind on nature. But no park boundary or conservation law can protect an ecosystem from climate change. A recent report by the World Wide Fund for Nature (WWF) states that this invisible killer has entered the most cherished natural areas. The giant pandas of Wolong in China, the grizzly bears of America’s Yellowstone National Park, and the tigers in Kanha National Park in India are some of the animals at risk from Global Warming.
Food Security: Climate change could adversely affect food security and exacerabate malnutrition at low latitudes, especially in seasonally dry and tropical regions, where crop productivity is projected to decrease for even small local temperature increases (1 to 2°C). By 2020, in some African countries, yields from rainfed agriculture could be reduced by up to 50 per cent. Agricultural production, including access to food, in many African countries is projected to be severely compromised.
Threat to Amazon Forest
Global warming will wreck attempts to save the Amazon rainforest, according to a devastating new study which predicts that one-third of its trees will be killed by even modest temperature rises. The research, by British climate change specialists, shows even severe cuts in deforestation and carbon emissions will fail to save the rainforest, the destruction of which has become a powerful symbol of human impact on the planet.
Up to 85 per cent of the forest could be lost if greenhouse gas emissions are not brought under control, the experts said. Even under the most optimistic climate change scenarios, the destruction of large parts of the forest is “irreversible.”
According to the study, the impacts of climate change on the Amazon are much worse than we thought. As temperatures rise quickly over the coming century the damage to the forest would not be obvious straight away, but the researchers could be storing up trouble for the future.
The new study used computer models to investigate how the Amazon would respond to future temperature rises. It found that a 2{+0}C rise above pre-industrial levels, widely considered the best-case global warming scenario and the target for ambitious international plans to curb emissions, would still see 20 per cent -40 per cent of the Amazon die off within 100 years.
A 3{+0}C rise would see 75 per cent of the forest destroyed by drought over the following century, while a 4{+0}C rise would kill 85 per cent.
Effects on India
A new report released recently by India’s scientists has revealed that India has almost consistently experienced more than normal annual mean temperatures for the past 14 years, with 2006 being the warmest recorded so far. The statistics contained in the “Annual Climate Summary 2006”, a report produced by the National Climate Centre Office of the Additional Director General of Meteorology (Research) Meteorological Department, Pune revealed warming at the rate of 0.48 degrees Celsius over 100 years. The report clearly demonstrated that since 1993, there had not been a single year when annual mean temperature was less than the normal, remaining towards the higher side for all the years.
Records show that prior to 1991, the annual mean temperatures were more than the normal in some years while in others, these were less than normal. Between 1901 and 1941, annual average temperatures were below normal for many years while since then, years with annual average temperature anomalies towards the higher side of the normal became more frequent. The year 2006 was the warmest year on record since 1901, according to the report. It was characterized by annual mean temperature over the country as a whole being 0.59 degrees celsius above the average calculated during 1961-1990. Minimum temperatures were more than two degrees Celsius above normal over northern parts of the country.
The report states that during 2006, a number of cyclonic storms and depressions formed over the Indian seas. Severe cold wave conditions over northern and eastern parts of the country claimed more than 80 lives. Heat wave events over northern and some western parts of the country claimed close to 100 lives and as many as 1500 persons were killed in floods during the monsoon season.
The 10 warmest years ever since the Met Department started keeping a record of temperatures since 1901 are 2006 (0.595), 2002 (0.59), 1998 (0.50), 2004&2001 (0.47), 2003 (0.45), 1958 (0.43), 1941 (0.41), 2005(0.,40), 1999 (0.39), 1953 & 2000 (0.36) and 1980 (0.34).
An anomaly was that whereas traditionally dry areas like Saurashtra and Kutch and West Rajasthan, besides Gujarat, Madhya Maharashtra and Orissa, received excess rainfall, Himachal Pradesh, east and west Uttar Pradesh, Bihar, Jharkhand and Assam and Meghalaya remained deficient. But overall the country received 100 per cent normal rainfall. During February, northern hilly regions, Uttrakhand, Himachal and parts of Jammu and Kashmir were abnormally warmer with maximum temperatures six to eight degrees above normal.
India’s Action Plan
The National Action Plan on Climate Change was finalised and released by Prime Minister Manmohan Singh in June 2008. The Plan finally weds India’s international negotiating stance with a domestic agenda on reducing greenhouse gas emissions.
The Plan contains a canvas for eight missions on climate mitigation and adaptation. According to the plan, the relevant ministries was asked to draw up detailed plans and presented them before the PM’s Climate Change Council. The Plan, though a roadmap for action on the domestic front, is bound to back up the India position.
Besides the push in solar energy, the Plan also suggests making it mandatory for power grids to purchase renewable energy from producers and set up progressive targets to do so over the coming years. While the move towards solar and solar derivatives is bound to reduce the dependence of fossil fuels, the Plan also puts as much emphasis on demand side management—reducing consumption levels in both industry and housing sectors. The Government envisages saving 10,000 MW by 2012 through energy efficiency measures.
The Plan will help bolster the country’s argument that it is ready to take an array of ‘no-regret’ actions—steps towards a low carbon economy that do not come at the cost of its poverty alleviation and growth targets.
Preventive Measures
Reduction in the use of non-renewable sources of energy and increased use of renewable sources will undoubtedly decrease the emission of GHGs substantially. This decrease in the GHGs will have a positive affect on the health and well-being of the people.
Furthermore, switching to cleaner fuels and energy-efficient technologies will reduce local pollutants and therefore, have an added beneficial impact on health.
The impacts of climate change are global and unequivocal, but ironically are felt most by the poorer sections of society who have contributed least in polluting the environment. The measures adopted for combating climate change would also translate into action against poverty, and organisations like TERI have a responsibility to create a climate for this change.
India needs to take the lead and be a frontrunner in taking steps to tackle climate change. The Prime Minister’s Council on Climate Change is currently working on a national programme to address various relevant issues. However, the recommendations of this plan would require commit ments of time and resources from all sections of society including governments, businesses, and the civil society. In this context, India’s 11th Five-year Plan (2007-12) articulates strategies in the areas of afforestation, sustainable energy use, flood protection, transportation and financial instruments such as capital debenture funds.
Developing countries need to find a middle path between development and addressing the sustainability challenges with the forward-looking policy interventions. For example, the subsidies on products like kerosene could be shifted to environmentally benign technologies such as solar devices.
