Water is a critical ingredient to all life on Earth and is without substitute. Although there is an abundance of water globally, only a limited amount of that water is suitable for human consumption and just a fraction of that is accessible through current technologies. As populations continue to grow and temperatures continue to rise, the already finite stock of fresh water is being drawn on at an exponential rate. An important question to ask then is how will a changing climate affect the hydrologic cycle in the future? As temperatures change, so will the distribution and availability of fresh water. The potential for global warming to disturb fresh water resources is tremendous, so it is important to predict and prepare for these changes. This article focuses on the effects of climate change on fresh water resources in India and discusses the potential impacts on the country’s demography. The predicted effects of global warming vary, but India is especially susceptible in terms of environmental, economic, and social impacts. India has one of the largest populations in the world and depends heavily on agriculture. As a result, there is a huge demand for fresh water. With an increase in temperature, the distribution and availability of fresh water is likely to change and the country’s demography will be forced to follow.
II. The Essay
This article interprets emission projections from the IPCC as well as information from other relevant sources to describe the expected pressures of climate change on fresh water resources in India over the next century. These sources indicate that India will experience more intense monsoon seasons with less rainfall during the winter, which will result in regular extreme weather events and a shift in India’s demography as its agricultural sector could be crippled. There is some skepticism as to how severe the effects of climate change will actually be, but predictions show that India will be put under immense pressure to provide for its people as fresh water resources diminish. The conceptual model included supports the IPCC predictions and describes how climate change might affect the hydrology of India (Figure 1).
India is a unique location in terms of its geography and demographic characteristics. With the Indian Ocean bordering the south and the Himalayan Mountains in the north, India has an incredibly diverse landscape that transitions through forests, deserts, plains, and mountains. Home to more than a billion people, India’s landscape is put under tremendous pressure to provide for its dense population. Fresh water is an especially important resource as India relies heavily on irrigation to keep up food production: “About 83% of the available water is used for agriculture alone” (Mall, et al. 2006). With an increasing demand and only a limited supply, fresh water is becoming more and more difficult to come by.
In the past few decades, India has seen rapid growth in its populations as well as its economy, industry, and agricultural sector. India’s growth coupled with climate change has put a huge strain on the nation’s fresh water resources: “Urban agglomeration is causing radical changes in groundwater recharge and modifying the existing mechanisms.” (Misra, 2011). India’s large, developing population is forcing climate change that will no doubt have an affect on the hydrology of the region (Table 1). The IPCC Special Report Emissions Scenarios from 2000 predict greenhouse gas emissions to increase in the future, leading to higher temperatures and more precipitation by 2100 (Rupa Kumar, et al. 2006). Climate change will disturb the distribution and availability of fresh water in India, which will result in a number of social, economic, and environmental repercussions.
Anthropogenic greenhouse gas emissions are a large contributor to the changing climate and are set to grow as developing countries like India transition into a more stable position. The effects of these emissions on temperature and rainfall patterns have a number of implications, including increased chance of water-borne diseases, loss of soil fertility, and decreased agricultural productivity (Sharma, Bhattacharya, 2003). As these changes take effect India’s agriculture will perish, its economy will be crippled, and its demographic transition will be delayed. Higher birth and death rates, extreme levels of poverty, and instances of disease are likely to follow these changes.
Together with the effects of climate change, overuse of fresh water is set to cause major changes in India’s environment and economy. Fresh water constitutes only about 2.5% of the globe’s 13,860,000 km3 stock of water (Postel, Daily, Ehrilich, 1996). As climate changes and India increases its consumption of this vital resource, things like drought, salt-water intrusion, and pollution will become more common (Figure 1). Extreme events such as flooding and landslides will also occur more frequently with rising temperatures (Milly, et al., 2002). Therefore, it is important for India to prepare for a number of possible climate change scenarios in which fresh water distribution and availability will evolve.
As temperatures continue to rise, India’s landscape will be altered in many ways. Based on the 2000 SRES ‘Marker’ scenarios from the IPCC, the temperature in India is expected to increase 1.4 – 5.5°C depending on emission levels (Lal, 2001). This shift in temperature has the potential to change weather patterns and in turn the landscape of the country. By the year 2100, India will be faced with regular drought patterns and intense rain during monsoon season, which will lead to higher incidence of extreme rainfall events (Mall, et al. 2006). Flooding and landslides, especially in the Himalayan region, could become a common theme of the future.
Although most climate change scenarios predict increased rainfall and extreme weather events over the next century, it is difficult to know exactly what to prepare for. India is expected to experience up to a 25% decrease in winter precipitation and a 7-10% increase in summer precipitation (Lal, 2001). This change in precipitation will have both regional and national effects (Table 1). For example, water stress may dry out soils to a point that they are unable to absorb the intense monsoon rains, resulting in more runoff and even greater water stress (Mall, et al. 2006). The potential for climate change to disrupt fresh water resources varies as India has such a diverse landscape, but the likelihood of disaster will only increase as temperatures continue to rise.
India’s diverse landscape makes it prone to most natural disasters, but as the climate changes it is likely that these disasters will occur much more frequently. The effects of extreme weather events can create a vicious cycle where damage can be compounded by hunger, which can increase chance of disease, and so on until entire regions are displaced (Schmidhuber, Tubiello, 2007). As fresh water becomes less available, crops are unable to produce as much. So climate change can also lead to increased risk of disease and hunger.
The effects of climate change act like a series of dominos, complicating much more than just fresh water resources. For example, more severe weather events coupled with increased levels of runoff can cause rivers to change direction (Singh, Sontakke, 2002). Migrating rivers are a huge concern because they increase the risk of flooding and can cause displacement of millions. With India’s landscape under immense pressure as it is, just a slight increase in temperatures can result in many environmental and social catastrophes.
Climate change predictions by the IPCC suggest that India’s fresh water resources will become scarce in some areas and a hazard in others as weather patterns change throughout the century. India’s policy makers will face many tough decisions in the near future as water resources change and the country continues to grow. There are a number of challenges that policy makers must overcome in order to prepare for the changing climate. For example, the government needs money to fund projects and further research is necessary to ensure the accuracy of these predictions. There is no doubt that India’s hydrology will be affected by climate change, but further research is needed for policy makers to know exactly what to prepare for. Although there is some variability in the predictions, most sources suggest that India’s booming cities and large agricultural industry will be crippled by these changes unless measures are taken to prepare for them. Climate change is an expensive and dangerous product of GHG emissions, but its effects can can be amplified if we do not predict and prepare for them.
Figure 1: Model of climate change and possible impact on the hydrologic cycle (Trenberth, 1999)
Table 1: Regional Impacts of Climate Change by 2100 (Mall, et. al, 2006)
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