Keywords

1 Introduction

The northwest arid zone of India encompasses the popularly known Thar Desert which marks the eastern end of the mid-latitude desert belt. It is characterized by a monsoonal pattern of rainfall distribution. The mean annual rainfall ranges from ~450 mm in the wettest eastern margin to less than 150 mm in the driest part. However, this constitutes only a small fraction of the mean annual potential evapotranspiration that has a spread of 1,400 mm to more than 2,200 mm. Major landforms comprise sandy plains and dunes, alluvial plains and rocky-gravelly pediments with scattered hills. The region has more than 700 species of vegetation. Most of these are well-adapted to harsh and uncertain environment and useful as a feed, fuel wood, or thatch making. Despite its high aridity, the region boasts of a world-renowned civilization, namely, the Indus/Harappan/Saraswati, that flourished during 3300–1600/1300 CE in the then riverine tract at the western margin of the Thar Desert. However, this civilization did not extend from its niche to the arid zone proper. That region instead was occupied by hunters and food gathering tribes.

The real influx of people into the region began about 2,000 or so years ago. However, population all through was marked by a sluggish growth with large variation in numbers due to drought-related famines and associated disease epidemics. Major livelihood source during mediaeval times was animal husbandry but since then arable farming has taken over. The twentieth century has been marked by a huge population expansion and intensification of agriculture. This has meant an overexploitation and degradation of land resources. For many a centuries, livelihoods have been at the subsistence level in a conservative, traditional environment, but in the past few decades, there have been profound improvements in lifestyle and social milieu. Scientific research has produced a wealth of knowledge and new technologies. With greenhouse-induced warming becoming a global agenda, studies have been made on future climate, particularly the predicted rainfall regimen in the Thar. Hot topics for discussion and debate include land use, socioeconomics, livelihoods and global warming. Several of these have a long history of research and study behind them.

2 The Indus/Harappan/Saraswati Civilization and the Climate

The archaeological sites of this grand culture, when discovered in year 1931, lay along Indus River and its tributaries, but investigations since then have shown far greater concentration of these along the Ghaggar-Hakra River, the course of which mostly ran parallel to and a few kilometre to the east of Indus River and had an independent exit to Arabian Sea. However, presently this river is lying in a dysfunctional and disorganized form with no flow to the sea. This culture is subdivided into three stages, namely, Early Harappan (3300–2600 CE), Mature Harappan (2600–1900 CE) and Late or Degenerate Harappan (1900–1600 CE). This civilization distinguished by its well-developed and diversified agricultural economy, societal organization and development of a unique script (Fig. 7.1). At its peak, i.e. Mature Harappan period, it enjoyed a high degree of affluence, agricultural surpluses and outstanding urbanization that permitted blossoming of art and culture and long-distance trade. A variety of household ceramics and exquisite jewellery made from semi-precious and precious stones, bone and seashells are evidences of the same.

Fig. 7.1
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Some artefacts of Harappan civilization: (a, b) seals; (c) a terracotta (Source: Wikipedia)

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For our present purpose, this grand civilization is discussed from the view point of climate change. Regarding the decay and end of this culture, several arguments have been put forward, namely, a devastating flood, climate deterioration, soil exhaustion, land degradation, Aryan invasion, shift of river courses, earthquake, etc. (Wright 2010). Hypothesis favouring the drainage desiccation arising from shift in river courses, not an uncommon feature for the area, were put forward by Agrawal and Sood (1982) and by Misra (1984) on the ground that the existing catchment of river Ghaggar/Hakra, assuming even a higher rainfall of the Mid-Holocene, could not have generated a flow in terms of durability and volume needed to sustain this exalted civilization at the tail end, some 800 km away from the source. Prior to this, Yashpal et al. (1980) have shown from remote sensing the existence of several paleochannels, both of the present-day Sutlej and of Yamuna, that flowed to the Ghaggar in the past. Valdiya (2013), based on geological and Vedic literature, also favoured this possibility. However, studies of Giosan et al. (2012) based on incision pattern in upstream region, and of Clift et al. (2012) based on sediment dating and the mineralogy, suggest that the Yamuna River had abandoned its southwestern course to Ghaggar about 50,000 years in the past. Clift et al. (2012) further showed that Sutlej continued to flow into Ghaggar for a long time thereafter but shifted its course to become a tributary of Indus system well before 10,000 years BP.

Climate deterioration has been suggested as another possibility for decay of this grand civilization. In a comprehensive review, Fuller and Madella (2001) show dominance of wheat and barley in cropping pattern as also presence of peas and perennial horticultural crops during the Mature Harappan period. The summer crops, particularly low water requiring millets, constituted a small fraction only of the cropping. However, during Late or Degenerate Harappan period, summer crops dominated the scene (Madella and Fuller 2006). Similarly, there was a large change in distribution and size of settlements also. The settlements during Late Harappan period not only got smaller but like the settlements of the succeeding/contemporary Painted Grey Ware Culture, they spread to the north in plains of present-day Punjab, Haryana and western Uttar Pradesh as also to south in northwestern Gujarat (Suraj Bhan 1973; Mughal 1982). Further, an independent support of the climate deterioration theory comes from the Thar Desert proper. Singh et al. (1990) showed from palynological, salt composition and distribution and lake-level studies on Didwana Salt Lake that during early and middle part of Holocene, i.e. the period from 10 to12,000 years BP, and particularly from 7,500 to 6,200 years BP, was largely wetter than the present, though with some fluctuations of lake level. Thereafter, arid conditions set in leading to complete drying up of the lake. Another study (Enzel et al. 1999) from Lunkaransar Lake, some 150 km to the northwest of Didwana Lake, while supporting mid-Holocene wet regime, showed that lake-full stage started declining from 4,800 BP and that lake completely dried by 4,000 years BP. The lake continues to exist in its dry state ever since. Importantly, they, like Singh et al. (1990), showed also that besides the summer season monsoon, winter rainfall made a significant contribution also to lake hydrology during the wetter past. Thus, presently amongst the various hypotheses, climate deterioration remains the most plausible reason for the demise of this grand culture, although the scope is not exhausted for more investigations.

3 History of Human Settlement, Population Growth, Land Use and the Recent Phenomenal Developments

Though the above-described Saraswati and the subsequent Chalcolith civilizations had flourished at its western and northern fringes, the Thar proper was devoid of any settlements of that period. Historians believe that influx of people into this region started at the beginning of the first millennium. This entry happened from the settlements up in the north, where apprehending invasions from the west, the people moved into this environmentally harsh but otherwise secure region. Further, there was a movement from the present-day Gujarat region in the south, where a well-established population was in existence also. This is evidenced by the presence of ancient towns like Bhatnair (present-day Hanumangarh) in the north and the Bhinmal in the south (Reu 1935). From then on, the population spread such that by the middle of first millennium, the central part comprising present-day Nagaur, then known as Itchipur, was well populated and also socially organized. It has a temple, Dadi Mata, dated to second to third centuries. Going further, by the close of this millennium, even the driest part in the west was settled, and it had also a political setup. However, all through the population was thin. An estimate for as late as the mid-seventeenth century informs that the present-day 280 mm rainfall tract had a population then that was less than one-third of that in existence in year 1941, thus showing that population density was low indeed over all this period. However, during this seventeenth-century period, the tract in 350–400 mm, watered further by the streams emanating from Aravalli Mountains, had a much higher density and well-established irrigated agriculture. For the subsequent period, an estimate of population for the early nineteenth century is available from Tod (1829–1832), who showed that in the tract with better rainfall, i.e. eastern part, the density was 30 persons/km2, in the intermediate tract (~250–350 mm rainfall) ~14 persons and for the western dry part just 4.6 persons/km2. Actually for this later mentioned dry area, 48% of the population was accounted for by the capital town of Jaisalmer alone, thereby giving a density for the rural area of just ~2 persons/km2. Thus, a vast difference existed in the density of population in relation to aridity from east to west, just as it exists even today.

From year 1891, regular decadal census data are available. These show that the human population up to year 1921, like that during Late Mediaeval period, had hardly any net growth. In fact the situation was one of large fluctuations, with climatically favourable period leading to some growth only to be followed by severe erosion during a successive famine period. A part of the nineteenth century, i.e. from years 1792 to 1854, experienced as many as 13 famines. For the remaining period of the nineteenth century, Narain et al. (2000) showed as many as seven famines and drought years, of which four lasted for two consecutive years. This situation of static (no net gain over a few decades) population shows how the harsh elements of nature, disease and a somewhat unstable/exploitative political system overwhelmed socioeconomic and demographic developments.

In comparison, the period from census year 1921 onwards is marked by one of continuous growth, the decadal growth rate being ~20% in the decades to year 1951 and ~30% from then on to census year 2001. It has been for the first time that the decade of 2001–2011 is marked by a decline to 20%. The growth rate all along has been much higher than that of Rajasthan and of India as a whole (Fig. 7.2).

Fig. 7.2
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Growth of population over the decades in Thar, Rajasthan and country as a whole (year 1921 = 100)

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Such an extraordinarily high growth rate during the past nearly a century is astounding indeed given that region is climatically challenged. Having a larger family had long been considered as a source of greater influence/strength and went with ability to command resources in the local context. Sociologists explain this as an outcome of early marriage of girls. Surveys of 1960s and 1970s showed that nearly 95% of girls in rural areas got married before they attained age of 15 years (Malhotra 1977; Bharara et al. 1984). The situation permitted a reproductive period of over three decades. Other reasons were the ethos as manifest in blessings of elders to a young woman to have numerous children (male in particular) and a social need to have a male child for performance of various religious ceremonies. To add to this was tenancy and land reforms, which brought in a degree of optimism in future. This situation prevailed during decades of 1920–1950s. But from then on, it was essentially the large decline in infant and maternal mortality rate. For example, the infant mortality rate per thousand live births in Rajasthan has fallen from 114 in 1961 to 83 by 1981 to just 60 in 2009 – a reduction by 50%. This rate currently in most of the desert districts is in fact 45–55 and thus is lower than the state average (Anonymous 2012).

3.1 Land Use

Records of land use for the mediaeval period are few, although it has been shown with a good degree of reasonableness that arable farming was in vogue in the Thar in an area adjoining present-day Gujarat in the fourth to fifth centuries. The arable farming from here spread to well-watered Luni River basin as the town of Pali located here was already a major commercial centre in early Mediaeval period. After the plunder of this town in the thirteenth century by Rathores, a section of Paliwals travelled all the way to Jaisalmer in the driest part and started niche agriculture by the fourteenth century. However, by far a major part of the Thar had pastoralism as the main pursuit. This situation continued even up to the middle seventeenth century since as inferred from Nainsi’s data, the cropped area in the ~280 mm tract then constituted a very small fraction of geographic area then, whereas the Luni Basin (referred to above) had a flourishing agriculture comprising as many as 7,400 wells producing crops such as sugarcane, opium, cotton, aniseed, caraway, vegetables and cucurbits (Bhadani 1980). From then on till the 1920s, the region experienced little growth of cropping activity (Balak Ram et al. 2013). However, the period thereafter saw an expansion. For example, Dhir (1982) showed a considerable expansion in area during the period from 1930 to 1958 in the central part of the erstwhile Marwar State. Jodha and Vyas (1969) and Dhir (1982) attributed this growth as a response to some degree of tenancy reforms and moderation in the grip by feudal system.

With independence in the year 1947 and amalgamation soon after of princely states, the region underwent land reforms such as ownership of land and distribution of land beyond a ceiling limit to landless and poor. Also the system of land records and land use data in a 16-point format and 12 land use classes was introduced. This system was in conformity with the national system in existence then. Besides, a survey was made twice in a year on the crop grown on individual agricultural fields. Thus, a wealth of information, with a fair degree of reliability, is available for study of dynamics of land use and of cropping pattern. The data (Table 7.1) for the year 1956–1957 shows that the net sown area for the Thar region as a whole then stood at 36.6% with an interdistrict range of ~70% in eastern most districts, ~40% in the centrally located districts and only 2% in the driest Jaisalmer (Fig. 7.2). The high incidence of cropping in Ganganagar District, despite its location in drier part, is due to existence of irrigation facility. The fallow lands are those where a crop has been raised in the past but are under rest since then. These lands are called “current fallow” if the crop has been raised in the preceding year and “long fallow” if the period since last cropping is more than 1 year. These lands constituted 21% of the region in year 1956–1957 and are particularly extensive in western half. The culturable wastelands category in Thar constitutes 25% of the area or 5.3 Mha and had its main occurrence in dry districts of Jaisalmer and Bikaner.

Table 7.1 Land use in Thar (in %) at three points of time over more than five decades
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But the period thereafter saw a considerable expansion of farming activity with the net sown area rising to 47.8% of Thar by year 1981–1982 and to 57.4% by year 2010–2011. This is due to three factors: (a) a reduction in the extent of fallow lands, (b) opening of new lands in the drier western half and (c) expansion of irrigation facilities. From the temporal distribution at district level data, it is seen that the eastern districts with higher rainfall had reached saturation as regards area suitable for cultivation in 1970s (Fig.7.3).

Fig. 7.3
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District-wise net cropped area as percent of geographic area at three time periods, namely, years 1956–1957, 1981–1982 and 2010–2011. The numeral at the bottom corresponds to earliest period, i.e. 1956–1957, whereas middle and upper numeral is for successive periods, respectively

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The main trigger for expansion was population growth (Dhir 1988). This factor continued to exert its influence even during the 1980s and 1990s but even more important became the coming onto the scene of tractors for cultivation. These machines enormously enhanced the capacity of farmers to sow their holding in the small time span of adequate moisture in the plough layer of sandy soils. This period saw also a large expansion of arable farming to the drier western part (Dhir 2003). In the subsequent period, both these factors lost much of their significance, and further growth has been due to expansion of irrigation. In fact this is the main factor that explains also the vast expansion of area sown more than once. In year 1956–1957, this area was only 0.23 million ha (Mha), and it has risen to 3.73 Mha by year 2010–2011, i.e. a 15-fold increase (Table 7.1).

3.2 Irrigation

Water is a constraint underlying all problems in a desertic tract. This is particularly so for agricultural activity where irrigation can make all the difference in land productivity. Therefore, development of water resources has received a major attention all along. This has been the situation in the historical past, with the royalty, as part of its public welfare concern or charity, have undertaken construction of reservoirs across ephemeral streams or rocky catchments, tanks, step wells and tankas (a water harvesting-based small storage structure for individual family or few families) or even bringing water from a river outside the region at a huge investment. In the post-independence era, development of irrigation based both on surface or groundwater sources became a major program to enhance and stabilize food production and to meet domestic water needs. Thar is an outstanding example of this effort. Groundwater exploration activities, comprising exploration, increased access to drilling technology, credit and rural electrification, were started in 1960s and ever since these have only got strengthened. Even a more ambitious effort was bringing of water from the rivers up north all the way to Thar over a distance of several hundred kilometres through a canal with a capacity to carry 10,601 million cubic meters (MCM) water annually and an objective to irrigate 1.5 Mha of parched lands of Thar. The project involved a huge monetary investment that included also the command area development and maintenance effort. As a result of these activities, the irrigated area has risen from 0.28 Mha under canal system and 0.22 Mha from wells in year 1956–1957 to 1.98 and 2.11 Mha from respective sources by year 2010–2011 – a nearly tenfold increase. A great effort indeed. In other words, of the total cropped area in Thar, 27% is irrigated by one or the other source now. Impact of irrigation in terms of agricultural production is still greater. In fact two-thirds of the value of crop production of the Thar is from irrigated lands.

4 Environmental Consequences of Land Use and Management

Arable farming and livestock rearing are the two major pursuits of desert dwellers. Arable farming both under irrigated and rainfed situations is essentially a fine blend of cropping and animal husbandry, i.e. a mixed farming enterprise. The crop residues and also some amount of green fodder sustain the livestock. In fact in the rainfed situation, livestock and their produce constitute almost the sole source of cash income. The system has several collateral benefits such as minimizing impact of drought, women empowerment and the much-needed increased employment of the farming household. Manure supply and fertilizing effect of animal penning are side benefits. There has been some change in herd composition; earlier it used to be largely cattle but with erosion of cow economy, it is now mainly goat and buffalo. Likewise, the pastoralists have shifted to a large extent from camel to sheep and goat. As explained above, the past six to seven decades have seen a large expansion of agricultural activity, a reduction of area under fallow lands as well as a tremendous loss of community grazing lands. This expansion of agricultural activity has occurred mainly in the western drier part, where the soils are sandy and wind regime is strong also. The use of a tractor as a means of cultivation has set in motion a process of accelerated wind erosion (Fig.7.4). This latter process causes removal of fertile soil particles as dust as well as near surface movement of sand (Dhir 1993). The sands redistribute locally and also travel some distance to encroach upon settlements or pile up against other obstacles, including sand dunes. In the process the lands lose some fertility and also levelness of the surface. The wind erosion is equally serious on community grazing lands, where overgrazing and consequential depletion of vegetation covers make these lands highly vulnerable also. The seriousness of problem of wind erosion has been mapped from time to time, and as per the latest estimate, 78% of the area of Thar is affected by this process, within which 16% is severely eroded. (Kar et al. 2009). The vegetational degradation problem is even more grievous. Though the past few decades have seen an enhanced dependence on crop residues and market purchased feeds, natural vegetation from designated grazing and other community lands have had a big role in meeting biomass needs of livestock and of fuel, wood and fencing material of desert dwellers.

Fig. 7.4
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Accelerated wind erosion is an outcome of current land use and management and a major manifestation of desertification problem. (a) Saltating sand deposits within field means a somewhat reduced fertility and a serious loss of land level. (b) Drift sands pile over dune flanks and crest. (c). These encroach also onto dwelling units

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However, due both to over grazing and agricultural land uses, the productivity and gross biomass availability have undergone severe erosion. The grazing lands have historically supported the traditional pastoralists. The livestock of farmers also used to substantially depend upon grazing on community lands in vicinity of the village and, during periods of scarcity, on distant lands in western thinly populated areas. The presence of high yielding perennial grasses and of shrubs and of multipurpose trees had ensured a high productivity in good (rainfall-wise) years and some productivity even in poor years. The deep-rooted trees and shrubs here provided some quantity of utilizable material even during extended droughts. But progressive increase in biotic pressure on the one hand and shrinkage of the area due to expansion of cultivation on the other have resulted in persistent overgrazing and severe loss of biomass production ability. The perennial grasses have almost disappeared and are replaced by very low yielding annuals and ephemerals. Thus, not only is there loss of productivity but also a reduced duration of the grazing period. In fact these lands are producing today one-third to one-fifth of that from a well-managed grassland (Table 7.2).

Table 7.2 Vegetation cover and yield under non-degraded and degraded condition
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Besides the grazing lands, the cropped lands invariably carry a good stand of highly useful shrub, like Ziziphus nummularia, and an equally important tree, namely, Prosopis cineraria, which are known to offer little competition for moisture for the growing annual crops and is an illustrious example of the traditional agro-forestry system. The stand of shrubs used to be 300–500 per hectare in 1950–1970s in 300–400 mm rainfall tract. It provided 50–200 kg of highly nutritious fodder that can be stored for up to 2 years. Likewise, in equal measure came another significant contribution from trees, particularly P. cineraria. Tractorization of plowing operation has resulted in virtual ruination of the stand of the useful shrub. The stand of the tree is adversely affected also due to casualty of the young replacement population. A study based on aerial photos of years 1958 and 1985 of a stand of principal agro-forestry tree, Prosopis cineraria, at 12 sites in Jodhpur district showed that whereas at 2 sites there was a population increase, the rest had a marked decline, with an overall decrease in stand of 14.4%. Similarly, the stand of other perennial vegetation such as Calligonum polygonoides, Acacia jacquemontii, Leptadenia pyrotechnica and Haloxylon spp. has suffered also. This depleted perennial vegetation cover under all land uses has meant also considerable loss of biodiversity. As per latest estimate (Pandey et al. 2012), the number of taxa in rare and threatened categories has reached to 43.

As mentioned earlier, irrigation is by far the biggest development, and of the total irrigated area, ~53% is from ground water sources. Withdrawal of water exceeds the recharge capacity and water tables are dropping. Current estimates show that water availability is 3,315 MCM, but demand is 5,056 MCM, i.e. 153% larger (Anonymous 2009) and many areas are facing a water table decline of 1–3 m per year. Clearly this is unsustainable and collapse of the system in inevitable, especially if climate change brings a warming trend and reduced or more erratic rainfall patterns.

5 Projections of Climate in a Global Warming Scenario

Increase in temperature is the most obvious outcome of current enhanced, and ever increasing, concentration of greenhouse gases. The Intergovernmental Panel on Climate Change (IPCC 2007) reports state that a rise of 0.8 °C in temperature of land and sea has already happened during the twentieth century. It is further projected that during the twenty-first century, there will be a further increase of 1.1–2.9 °C at the lowest emission scenario and 2.4–6.4 °C at the highest. Regarding Asia, the IPCC has predicted a temperature rise of 3 °C by end of 2050 and of 5 °C by 2080, and this warming is greater than that for the world as a whole. Looking to critical dependence of much of this region on monsoon, scientists have focused on its behaviour over time. Meehl and Washington (1993) employed a GCM model and projected an intensification of monsoon in a doubled CO2 situation. A later study by Lu et al. (2007) found a similar outcome but predicted also an expansion of subtropical deserts, to which Thar Desert also belongs. The IPCC ( 2007) review also projects an increase in occurrence of extreme weather phenomena including heat wave and intense precipitation events in South Asia, East Asia and Southeast Asia.

Regarding India, efforts to predict the extent of climate change have been made using both projections from recent trends in climate parameters and from use of global climate models. The India Meteorology Department worked out state-level trends for the period 1951–2010 and showed that in Rajasthan mean annual temperature and rainfall have increased at a rate of 0.01 °C and 0.04 mm per year, respectively (Rathore et al. 2013). Concerning the Thar region, Pant and Hingane (1988) analyzed over a 100-year instrumental record of rainfall for the period to 1980s at several rain gauge stations in Thar and found non-significant trend of rainfall. Instead Dash et al. (2009) from study on duration and intensity of rainfall have suggested a weakening of the summer monsoon circulation over India.

Analysis for an extended period to 2010 by Rao and Roy (2012) again did not show any systematic trend in rainfall over time. However, there were intra-regional variation with Ganganagar (in an irrigated tract in the north) showing an increase of rainfall at a mean rate of 1.2 mm/year, but out of 65 locations studied in Thar, 37 showed a decline in monsoon rainfall. For the recent period (1971–2011), Poonia and Rao (2013) showed a mean annual rainfall increase of 0.56 mm per year for the Thar as a whole. But individual stations showed varied trend. Projection of these for the closing period of the twenty-first century suggests rainfall to increase from the present 252 to 308 mm at Bikaner, from 176 to 234 mm at Jaisalmer and from 487 to 613 mm at Pali, but for Jodhpur, the rainfall is likely to decrease from 325 to 275 mm. They showed also based on this recent period trend that the mean annual temperature may increase by 3.3 °C at Bikaner, 3.4 °C at Jaisalmer, 2.9 °C at Jodhpur and 2.5 °C at Pali. Goswami and Ramesh (2008) used weighted epochal trend ensemble approach in analysis to assess future scenario of Thar based on trend analysis of the period 1990–2003 and suggested that the area of the Thar Desert is poised to expand greatly by the end of the twenty-first century.

Global modelling of climate in progressively warming condition has been a major exercise. Rupa Kumar et al. (2006) using regional climate model, PRECIS, showed that the all-India summer monsoon rainfall will increase by about 20% during the 2071–2100 period. The annual mean surface air temperature during this time slot is set to rise by 3–5 °C in one scenario and between 2.5 and 4 °C in the other. However, the Thar Desert and adjoining parts of northwestern India are expected to show little change or, in fact, a decline in rainfall of 10–15%. Rajendran and Kitoh (2008) carried out a study using a super high-resolution GCM, which enabled a far greater spatial resolution and also brought out clearly the orographic effect. The study concentrated on the later half of the twenty-first century, more specifically on the 10 year slot of years 2075–2084 period. The results showed a widespread but spatially heterogeneous increase in rainfall – much of peninsular and northern plain region marked by an increase in rainfall of 1–3 mm/day for summer monsoon period, but others had much less increase. The overall projected increase is shown at ~10%, which is less than the value of Rupa Kumar et al. (2006). The Thar region is expected to experience a modest increase of 0.5 mm or less. The results also show a large increase in days with temperature over 45 °C during pre-monsoon summer period and of those with temperature over 35 °C during monsoon period, the effect being at its maximum in northwestern part of the country, including Thar. Likewise, temperature projections showed substantial inter-model variation. For Thar, while showing considerable spatial variation, most models show little or no improvement in rainfall, while temperature increase was close to all-India average.

Kar (2012) made a study specifically for northwest arid zone of the country. Of the 15 GCMs and their ensemble under A2 scenario, Kar (2012) found the two models to predict better the 2001–2010 period rainfall and hence used these to predict rainfall regime for the period to mid of the twenty-first century. The results from both these models, albeit with some difference in magnitude, showed a decline in rainfall for the period from 2016 to 2030 with a spill over continuing to the period ending in 2050. Importantly, he worked also on likely wind erosion scenario, which showed that for much of Thar, coming decades will see a substantial increase in wind erosivity and the same will happen again in late 2040s onwards. Summing up, with a degree of uncertainty, most predictions are for a conspicuous rise in temperature, increased erraticity in distribution of rainfall as also its intensity. Regarding rainfall amount, most of the results do not show a systematic trend but some show a decline.

6 Implications and Vulnerability of Thar

Because of an exploitative use of natural resources, the region is already under going environmental deterioration. Degradation of vast community grazing land is very severe, besides of course, the loss of useful perennial vegetation on croplands. Wind erosion problem in general is considerable also and most of the dunes, which occupy 45–50% of the area of the Thar are semi-stabilized. This includes some area also of shifting dunes and hummocks, particularly in the windy western half of the Thar. The Central Arid Zone Research Institute has already been working since the 1960s on a huge program of technology development that comprises grassland rehabilitation under extreme habitat situations, sand dune stabilization with mini-wind breaks, identification of fast growing trees and nursery techniques for tree multiplication especially for road-side plantation. Wind erosion control on croplands, soil and moisture conservation were part of this activity. Therefore, concerned with deteriorating environmental degradation, the government launched a major effort under the aegis of Desert Development Program in year 1977–1978. Road and canal side plantation, village energy plantation and sand dune stabilization were some of the salient components of this effort, and about 0.3 Mha have been treated so far with considered success. But efforts to rehabilitate the community grazing land did not have much success, not because of any deficiency of technology but because of lack on grazing control. In the area of water resources, some efforts were made to expand the traditional water harvesting systems both for drinking (tankas) and for agricultural lands, i.e. khadin system. Likewise, a program of drought/famine relief was started also. Over time, with increased supporting capacity of central and state governments, human deaths from starvation are a thing of the past. Fodder is imported from all over. Though this is able to keep the most productive of the cattle alive, distress sale of animals and some mortality have been unavoidable.

Right from the beginning of independence era, a socialistic pattern of society has been a consistent and major policy of the government. Over time with the capacity of providing succour to the numerous poor and handicapped having increased, there has been no let-up of social upliftment effort. Reach and content of the welfare programs have been enhanced to include safe drinking water supply, literacy, skill development, strengthening of public health services, subsidized housing, rural roads and communication. Public distribution of essential commodities has been a major activity, and over time the entitlement and quantity of subsidized food grains have increased. Further, there has been a major reduction in cost of grain and fuel supplies for the people below the poverty line. Simultaneously, rural employment generation has been taken up also from 1980’s, and in fact from year 2006, it took the form of a watershed with launching of employment guarantee scheme that entitled every rural family a 100/150 days of employment at handsome wages. This had a profound effect not only in strengthening household economy but also in empowerment of women. Irrigation, as said above, is a major transformer of economic well-being of farmers, and to facilitate this, farmers are being supplied power for tube wells free or at nominal rates. Likewise, canal water supply is highly subsidized also. To cap it all and to minimize use of electric power, almost entirely generated by coal-based systems, solar power-based pumps are being supplied at 70–80% subsidy. New methods of irrigation are helpful also in economizing water use by crops. But, as mentioned earlier, the current rate of ground water withdrawal will cause exhaustion of most of the aquifers in another 10 years or so to undo the current gains.

The growth of a service sector and industry has been a contributing factor to a largely improved lifestyle and general well-being of desert dwellers. Liberal attitude and promotional effort have led to a fast development of solar energy utilization enterprises. From a modest start with just 5 MW capacity in year 2010–2011, there is an aggregated generation of 1,360 MW presently. Besides, projects amounting to another 15,000 MW capacity at a cost of 200 billion Indian rupees stand committed. But except for the solar energy, the support for socioeconomic developments, just mentioned, is externally sourced in Thar. Because of this conditionality, the local adaptive capacity based on indigenous biophysical and social resources is rather low. Little above the bare subsistence level living of rainfed farmers and pastoralists endows a poor buffering capacity of farmers to adjust to adverse environmental perturbations.

Rainfed farming and ground water-based irrigated farming are the pursuits of the largest part of population of the Thar. The predicted climate changes bode ill despite appropriate traditional management, comprising of mixed farming, well-adapted crops, mixed cropping and agro-forestry and the best technologies for both the farming systems. Besides the highly vulnerable indigenously sourced ground water supply for irrigation, even the precious canal-irrigated area, with its externally sourced water, is liable to suffer. Firstly, the increased atmospheric temperature will mean increased water requirements for crops. Rao and Poonia (2011) have shown that an increase of 3 °C will mean a 9–10% higher water need for monsoon season crops and 13–14% for winter season crops. Further, higher temperature during the most important winter season (productivity-wise) will reduce the length of growing season thereby adversely affecting the crop yields. Among the other biotic stresses, the problem of pests and diseases is going to be aggravated.