If it continues the same way, will it mean doom for the Mother Earth that has been rearing her children so lovefully, warns Dr S A Shameem
Since the Little Ice Age period, which peaked in the mid-late 19th century, global temperatures has risen at the rate of about 1o C because of both natural and anthropogenic causes most resulting of the high temperature records in the 1990s. According to Intergovernmental Panel on Climate Change (IPCC), the increase in global temperature will continue during the 21st century as a result of greenhouse gas emission. For South Asia, an above average increase is predicted. On the Indian sub-continent temperatures could rise between 3.5 and 5.50C by 2100.
The increase in annual mean temperatures will not cause the biggest problem for plants, animals and human beings. Climate change is not just above averages, it is also a matter of extremes. Climate change is likely to affect minimum and maximum temperatures and trigger more extreme rainfall events and storms. For the Indian sub-continent, less rainfall in winter and increased precipitation in summer monsoon are predicted; and in 2050 decrease in winter precipitation by 10-20% and by 30% for the summer have been projected. This means that we can expect an increase in droughts in winter and floods in the summer monsoons.
In high altitude areas, an increased annual average temperature will cause thawing of perennial snow and Ice. In short term, this may led to an increase in an annual discharge in rivers, since a great proportion of river water comes from snow and ice. However, in the long run the annual discharge may decreases and the discharge in dry season decline, further limiting water supplies for communities downstream. The increase precipitation predicted during summer monsoon for the Indian sub-continent is likely to increase the frequency and magnitude of extreme rainfall events, in turn implying a possible increase in severe flash floods. In addition climate warming in the region will cause glacial meltdown, increasing pressure on moraine ridges damming highly elevated pro-glacial lakes, hence increasing the rise of glacial lake outburst (GLOF) events.
Today poor water quality kills more people than any other single factor. Worldwide, 1.5 million people die every year from water-borne diseases. The problems of water quality may be exacerbated by climate change. The possible increase in differences between wet and dry seasons may imply wetter wet seasons and drier dry seasons. Already access to safe water is limited throughout the globe. If dry seasons become even drier, this problem will grow, as it will increase pressure on existing water resources and force people to use water of poor quality; decreased access to water means being less able to maintain reasonable hygienic standards. As a result, the risk of water-borne diseases will increase.
The United Nations framework Convention on climate change (also known as the FCCC) stands at the basis of global efforts to combat global warming. The FCCC was adopted on 9 May 1992 and was opened for signature in June 1992 the UN Conference on Environment and Development, sometimes also called the Rio Earth Summit. It entered in to force on 21 March 1994, 90 days after 50 countries had ratified it. At present over 180 countries have ratified the Convention. The ultimate objective of the FCCC is the stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (man-made) interference with the climate system. This stable level should be reached within a time-frame which would allow ecosystems to adapt naturally to climate change, ensure that food production is not threatened and at the same time enable economic development to proceed in a sustainable manner.
Impacts of climate change
A temperature increase is expected particularly at high latitudes, and changes in rainfall at low latitudes. The response to the changes by organisms is relatively easy to assess at the ecophysiological level. It includes, for instance, short crop cycles, CO2 fertilization, modification of coastal/deliaic agriculture, modified crop/ animal and pest/disease relations. Major methodological difficulties are associated with the extrapolation of impacts to global scale. Very little is known about the spatial distribution of the more complex impacts. If expressed in terms of Grass Domestic Product from Agriculture (GDPA), and after making due provision for adaptation, impact could generally be positive in developed countries, and negative elsewhere. Some authors also cautiously suggest that by 2060 there may a relative decrease of the number of hungry people, but an increase in Africa when expressed in absolute terms. In Asia, on the other hand, there would be both a relative and absolute decrease.
Impacts on Water Resources:
While climate change may have a wide range of adverse impacts on global water resources, a bigger threat to the future availability and use of water may come from other factors, such as population growth, technology, and economic, social and political conditions. The most vulnerable domestic water shortages include those where access to water is already limited, the population is growing rapidly, urban centers are spreading, and the economy is burdened by financial problems and a lack of skilled workers. Even if the world maintained the pace of the 1990s in water-supply development, this would not be enough to ensure that everyone had access to safe drinking water by the year 2025.
The impacts of climate change - including changes in temperature, precipitation and sea levels-are expected to have varying consequences for the availability of freshwater around the world. For example, changes in river runoff will affect the yields of rivers and reservoirs the recharging of groundwater supplies. An increase in the rate of evaporation will also affect water supplies and contribute to the salinisation of irrigated agricultural lands. Rising sea levels may result in saline intrusion in coastal aquifers. Current indications are that if climate change occurs gradually, the impacts by 2025 may be minor, with some countries experiencing positive impacts while most experience negative ones. Climate change impacts are projected to become increasingly strong during the decades following 2025.
Impacts on Forests:
Although climate change is not necessarily a pleasant prospect to consider, its impacts on global forests in their entirely would in all likelihood be modest. However, impacts on individual forests could be substantial as they adapted to new climate conditions. New forests might rise up in the tundra. Others might wane in places where moisture levels declined. Overall, the impacts would likely be greatest in the higher latitudes, where more warming is expected.
The major negative impact would likely be on biodiversity, particularly on endemic species that would have difficulty migrating. Mitigating the negative impacts of climate change on forests will depend on enhancing the capacity for adaptation.
Impacts on mountain vegetation
Mountains cover about 20% of the Earth's continents and serve as an important water source for most major rivers. Paleologic records indicate that climate warming in the past has caused vegetation zones to shift to higher elevations, resulting in the loss of some species and ecosystems. Simulated scenarios for temperate-climate mountain sites suggest that continued warming could have similar consequences. Species and ecosystems with limited climatic ranges could disappear and, in most mountain regions, the extent and volume of glaciers and the extent of permafrost and seasonal snow cover will be reduced. Along with possible changes in precipitation this would affect soil stability and socio-economic activities such as agriculture, tourism, hydropower and logging. Resources for indigenous populations and recreational activities would also be disrupted.
Impacts on Agriculture
While global warming may make the achievement of sustainable agricultural production more difficult, especially in developing countries, a bigger threat may come from more immediate concerns, such a lags in the spending on agricultural research needed for development of new technology. Global warming may thus have profound effects on agriculture and food security. Crop agriculture, forestry and livestock are directly involved as sources or sink of GHG, but they are also among the most vulnerable victims of the foreseen changes
Sea level rise due to global warming
It is likely that much of the rise in sea level has been related to the concurrent rise in global temperature over the last 100 years. On this time scale, the warming and the consequent thermal expansion of the oceans may account for about 2-7cm of the observed sea level rise, while the observed retreat of glaciers and ice caps may account for about 2-5cm. Other factors are more difficult to quantify. The rate of observed sea level rise suggests that there has been a net positive contribution from the huge ice sheets of Greenland and Antarctica, but observations of the ice sheets do not yet allow meaningful quantitative estimates of their separate contributions. The ice sheets remain a major source of uncertainty in accounting for past changes in sea level because of insufficient data about these ice sheets over the last 100 years. Examples; Bangladesh, one of the world's poorest nations is also the country most vulnerable to sea-level rise. The population is already severely affected by storm surges. Catastrophic events in the past have caused damage up to 100 km inland. It is hard to imagine to what extent these catastrophes would be with accelerated sea-level rise. Another example is Nile Delta which is one of the oldest intensely cultivated areas on earth. It is very heavily populated, with population densities up to 1600 inhabitants per square kilometer. The low lying, fertile floodplains are surrounded by deserts. Only 2,5% of Egypt's land area, the Nile delta and the Nile valley, is suitable for intensive agriculture. Most of a 50 km wide land strip along the coast is less than 2 m above sea-level and is protected from flooding by a 1 to 10 km wide coastal sand belt only, shaped by discharge of the Rosetta and Damietta branches of the Nile. Erosion of the protective sand belt is a serious problem and has accelerated since the construction of the Aswan dam.
Oceans and coastal areas:
Rising sea level would destroy weak parts of the sand belt, which is essential for the protection of lagoons and the low-lying reclaimed lands. The impacts would be very serious: One third of Egypt's fish catches are made in the lagoons. Sea level rise would change the water quality and affect most fresh water fish. Valuable agricultural land would be innundated. Recreational tourism beach facilities would be endangered and essential groundwater would be salinated. Dykes and protective measurements would probably prevent the worst flooding up to a 50cm sea level rise. However, it would cause serious groundwater salination and the impact of increasing wave action would be serious.
Impacts on human health
The transmission of many infectious diseases is affected by climatic factors. Infective agents and their vector organisms are sensitive to factors such as temperature, surface water, humidity, wind, soil moisture, and changes in and forest distribution. Changes in climate will also affect infectious diseases transmitted by insects, i. e., vector-borne diseases: examples are malaria, yellow fever, and schistosomiases. These diseases are sensitive to temperature as well as land-use changes, which may interact in a complex manner. The distribution of vector-borne diseases is restricted by climate tolerance: a climatic change normally would affect the edges of land-use change and vector ecology control interactions between hosts and vectors, e.g., removal of vegetation or increased areas under irrigation influence the spread of diseases. It is therefore, projected that climate change and altered weather patters would affect the range (both altitude and latitude), intensity, and seasonality of many vector-borne and other infectious diseases. It is also important to identify adaptation measures to reduce future negative effects. While adaptive measures and interventions to protect human health from the consequences of climate change need immediate attention, mitigation measures.
Conclusion
Climate change is one of the greatest global environmental threats. It can dramatically affect the economy, infrastructure, natural resources and local livelihoods in developing countries. Depending on their specific site characteristics, developing countries are confronted with steadily changing conditions as well as increasing extreme climatic events such as droughts, hurricanes, and heavy rainfall that will increase the risk of so-called natural disaster.
These circumstances will affect inter alia food production, infrastructure, water supply, biodiversity, natural ecosystems, and human health. Developing countries will suffer disproportionately from negative impacts of climate change. In addition, processes of development will be retarded, and new sources of social conflict will arise as consequences of increasingly adverse climatic conditions. Therefore it is necessary to define actions aimed at reducing the vulnerability of poorer social groups and allowing them to participate equability in the new opportunities offered by global climate change policy. It is in this area that development co-operation finds a specific niche where it can address a global concern through activities at the local level.
Since the Little Ice Age period, which peaked in the mid-late 19th century, global temperatures has risen at the rate of about 1o C because of both natural and anthropogenic causes most resulting of the high temperature records in the 1990s. According to Intergovernmental Panel on Climate Change (IPCC), the increase in global temperature will continue during the 21st century as a result of greenhouse gas emission. For South Asia, an above average increase is predicted. On the Indian sub-continent temperatures could rise between 3.5 and 5.50C by 2100.
The increase in annual mean temperatures will not cause the biggest problem for plants, animals and human beings. Climate change is not just above averages, it is also a matter of extremes. Climate change is likely to affect minimum and maximum temperatures and trigger more extreme rainfall events and storms. For the Indian sub-continent, less rainfall in winter and increased precipitation in summer monsoon are predicted; and in 2050 decrease in winter precipitation by 10-20% and by 30% for the summer have been projected. This means that we can expect an increase in droughts in winter and floods in the summer monsoons.
In high altitude areas, an increased annual average temperature will cause thawing of perennial snow and Ice. In short term, this may led to an increase in an annual discharge in rivers, since a great proportion of river water comes from snow and ice. However, in the long run the annual discharge may decreases and the discharge in dry season decline, further limiting water supplies for communities downstream. The increase precipitation predicted during summer monsoon for the Indian sub-continent is likely to increase the frequency and magnitude of extreme rainfall events, in turn implying a possible increase in severe flash floods. In addition climate warming in the region will cause glacial meltdown, increasing pressure on moraine ridges damming highly elevated pro-glacial lakes, hence increasing the rise of glacial lake outburst (GLOF) events.
Today poor water quality kills more people than any other single factor. Worldwide, 1.5 million people die every year from water-borne diseases. The problems of water quality may be exacerbated by climate change. The possible increase in differences between wet and dry seasons may imply wetter wet seasons and drier dry seasons. Already access to safe water is limited throughout the globe. If dry seasons become even drier, this problem will grow, as it will increase pressure on existing water resources and force people to use water of poor quality; decreased access to water means being less able to maintain reasonable hygienic standards. As a result, the risk of water-borne diseases will increase.
The United Nations framework Convention on climate change (also known as the FCCC) stands at the basis of global efforts to combat global warming. The FCCC was adopted on 9 May 1992 and was opened for signature in June 1992 the UN Conference on Environment and Development, sometimes also called the Rio Earth Summit. It entered in to force on 21 March 1994, 90 days after 50 countries had ratified it. At present over 180 countries have ratified the Convention. The ultimate objective of the FCCC is the stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (man-made) interference with the climate system. This stable level should be reached within a time-frame which would allow ecosystems to adapt naturally to climate change, ensure that food production is not threatened and at the same time enable economic development to proceed in a sustainable manner.
Impacts of climate change
A temperature increase is expected particularly at high latitudes, and changes in rainfall at low latitudes. The response to the changes by organisms is relatively easy to assess at the ecophysiological level. It includes, for instance, short crop cycles, CO2 fertilization, modification of coastal/deliaic agriculture, modified crop/ animal and pest/disease relations. Major methodological difficulties are associated with the extrapolation of impacts to global scale. Very little is known about the spatial distribution of the more complex impacts. If expressed in terms of Grass Domestic Product from Agriculture (GDPA), and after making due provision for adaptation, impact could generally be positive in developed countries, and negative elsewhere. Some authors also cautiously suggest that by 2060 there may a relative decrease of the number of hungry people, but an increase in Africa when expressed in absolute terms. In Asia, on the other hand, there would be both a relative and absolute decrease.
Impacts on Water Resources:
While climate change may have a wide range of adverse impacts on global water resources, a bigger threat to the future availability and use of water may come from other factors, such as population growth, technology, and economic, social and political conditions. The most vulnerable domestic water shortages include those where access to water is already limited, the population is growing rapidly, urban centers are spreading, and the economy is burdened by financial problems and a lack of skilled workers. Even if the world maintained the pace of the 1990s in water-supply development, this would not be enough to ensure that everyone had access to safe drinking water by the year 2025.
The impacts of climate change - including changes in temperature, precipitation and sea levels-are expected to have varying consequences for the availability of freshwater around the world. For example, changes in river runoff will affect the yields of rivers and reservoirs the recharging of groundwater supplies. An increase in the rate of evaporation will also affect water supplies and contribute to the salinisation of irrigated agricultural lands. Rising sea levels may result in saline intrusion in coastal aquifers. Current indications are that if climate change occurs gradually, the impacts by 2025 may be minor, with some countries experiencing positive impacts while most experience negative ones. Climate change impacts are projected to become increasingly strong during the decades following 2025.
Impacts on Forests:
Although climate change is not necessarily a pleasant prospect to consider, its impacts on global forests in their entirely would in all likelihood be modest. However, impacts on individual forests could be substantial as they adapted to new climate conditions. New forests might rise up in the tundra. Others might wane in places where moisture levels declined. Overall, the impacts would likely be greatest in the higher latitudes, where more warming is expected.
The major negative impact would likely be on biodiversity, particularly on endemic species that would have difficulty migrating. Mitigating the negative impacts of climate change on forests will depend on enhancing the capacity for adaptation.
Impacts on mountain vegetation
Mountains cover about 20% of the Earth's continents and serve as an important water source for most major rivers. Paleologic records indicate that climate warming in the past has caused vegetation zones to shift to higher elevations, resulting in the loss of some species and ecosystems. Simulated scenarios for temperate-climate mountain sites suggest that continued warming could have similar consequences. Species and ecosystems with limited climatic ranges could disappear and, in most mountain regions, the extent and volume of glaciers and the extent of permafrost and seasonal snow cover will be reduced. Along with possible changes in precipitation this would affect soil stability and socio-economic activities such as agriculture, tourism, hydropower and logging. Resources for indigenous populations and recreational activities would also be disrupted.
Impacts on Agriculture
While global warming may make the achievement of sustainable agricultural production more difficult, especially in developing countries, a bigger threat may come from more immediate concerns, such a lags in the spending on agricultural research needed for development of new technology. Global warming may thus have profound effects on agriculture and food security. Crop agriculture, forestry and livestock are directly involved as sources or sink of GHG, but they are also among the most vulnerable victims of the foreseen changes
Sea level rise due to global warming
It is likely that much of the rise in sea level has been related to the concurrent rise in global temperature over the last 100 years. On this time scale, the warming and the consequent thermal expansion of the oceans may account for about 2-7cm of the observed sea level rise, while the observed retreat of glaciers and ice caps may account for about 2-5cm. Other factors are more difficult to quantify. The rate of observed sea level rise suggests that there has been a net positive contribution from the huge ice sheets of Greenland and Antarctica, but observations of the ice sheets do not yet allow meaningful quantitative estimates of their separate contributions. The ice sheets remain a major source of uncertainty in accounting for past changes in sea level because of insufficient data about these ice sheets over the last 100 years. Examples; Bangladesh, one of the world's poorest nations is also the country most vulnerable to sea-level rise. The population is already severely affected by storm surges. Catastrophic events in the past have caused damage up to 100 km inland. It is hard to imagine to what extent these catastrophes would be with accelerated sea-level rise. Another example is Nile Delta which is one of the oldest intensely cultivated areas on earth. It is very heavily populated, with population densities up to 1600 inhabitants per square kilometer. The low lying, fertile floodplains are surrounded by deserts. Only 2,5% of Egypt's land area, the Nile delta and the Nile valley, is suitable for intensive agriculture. Most of a 50 km wide land strip along the coast is less than 2 m above sea-level and is protected from flooding by a 1 to 10 km wide coastal sand belt only, shaped by discharge of the Rosetta and Damietta branches of the Nile. Erosion of the protective sand belt is a serious problem and has accelerated since the construction of the Aswan dam.
Oceans and coastal areas:
Rising sea level would destroy weak parts of the sand belt, which is essential for the protection of lagoons and the low-lying reclaimed lands. The impacts would be very serious: One third of Egypt's fish catches are made in the lagoons. Sea level rise would change the water quality and affect most fresh water fish. Valuable agricultural land would be innundated. Recreational tourism beach facilities would be endangered and essential groundwater would be salinated. Dykes and protective measurements would probably prevent the worst flooding up to a 50cm sea level rise. However, it would cause serious groundwater salination and the impact of increasing wave action would be serious.
Impacts on human health
The transmission of many infectious diseases is affected by climatic factors. Infective agents and their vector organisms are sensitive to factors such as temperature, surface water, humidity, wind, soil moisture, and changes in and forest distribution. Changes in climate will also affect infectious diseases transmitted by insects, i. e., vector-borne diseases: examples are malaria, yellow fever, and schistosomiases. These diseases are sensitive to temperature as well as land-use changes, which may interact in a complex manner. The distribution of vector-borne diseases is restricted by climate tolerance: a climatic change normally would affect the edges of land-use change and vector ecology control interactions between hosts and vectors, e.g., removal of vegetation or increased areas under irrigation influence the spread of diseases. It is therefore, projected that climate change and altered weather patters would affect the range (both altitude and latitude), intensity, and seasonality of many vector-borne and other infectious diseases. It is also important to identify adaptation measures to reduce future negative effects. While adaptive measures and interventions to protect human health from the consequences of climate change need immediate attention, mitigation measures.
Conclusion
Climate change is one of the greatest global environmental threats. It can dramatically affect the economy, infrastructure, natural resources and local livelihoods in developing countries. Depending on their specific site characteristics, developing countries are confronted with steadily changing conditions as well as increasing extreme climatic events such as droughts, hurricanes, and heavy rainfall that will increase the risk of so-called natural disaster.
These circumstances will affect inter alia food production, infrastructure, water supply, biodiversity, natural ecosystems, and human health. Developing countries will suffer disproportionately from negative impacts of climate change. In addition, processes of development will be retarded, and new sources of social conflict will arise as consequences of increasingly adverse climatic conditions. Therefore it is necessary to define actions aimed at reducing the vulnerability of poorer social groups and allowing them to participate equability in the new opportunities offered by global climate change policy. It is in this area that development co-operation finds a specific niche where it can address a global concern through activities at the local level.
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