Thar Desert Climate Change: Evidence of Extremes

The Thar Desert, extending into Pakistan’s Sindh province, represents one of the most densely populated arid zones in South Asia. Unlike many desert ecosystems characterized by sparse human settlement, Thar supports a substantial rural population reliant on rain-fed agriculture and livestock rearing. This demographic pressure intensifies competition over already limited water, pasture, and arable land resources (Meghwar et al., 2020). Climatically, the region is defined by high interannually variability, erratic monsoon rainfall, prolonged dry spells, and extreme temperature regimes.

Historical assessments indicate that during the twentieth century, mean temperatures in the region increased by approximately 1.0 to 2.5 °C, accompanied by a decline in average precipitation of 5–12 mm and humidity fluctuations ranging from 5–25 percent (Meghwar et al., 2020). These climatic shifts have heightened the frequency and severity of drought episodes, accelerated evapotranspiration rates, and reduced soil moisture retention, thereby undermining agricultural productivity and groundwater recharge. The combined effects exacerbate food insecurity, malnutrition, and forced seasonal migration.

This article draws upon a 17-year meteorological dataset (2004–2020) obtained from the Pakistan Meteorological Department Mithi station to provide an updated empirical analysis of local climatic trends. By examining temperature patterns, rainfall variability, and humidity dynamics, the dataset offers granular insight into evolving microclimatic conditions within Thar. Establishing this evidence-based baseline is critical for informing adaptive water management strategies, climate-resilient agricultural planning, and policy interventions aimed at mitigating environmental stress in one of Pakistan’s most climate-sensitive regions. All statistical observations and trend analyses referenced herein are derived directly from this PMD dataset unless otherwise noted.

Integrated Analysis of Climatic Extremes and Hydro-Meteorological Stress

This section presents a comprehensive assessment of key climatic variables derived from the 2004–2020 dataset recorded at the Mithi station in the Thar Desert, located in Sindh, Pakistan. The analysis reveals a climate system characterized by extreme thermal variability, erratic rainfall, fluctuating humidity, strong seasonal winds, and exceptionally high atmospheric water demand collectively reinforcing the region’s structural vulnerability.

Maximum temperature dynamics confirm intense and persistent heat stress. Average annual maximum temperatures ranged between 34.6 °C and 36.9 °C, over the study period. The seasonal cycle is sharply defined: mean monthly maxima increase from 27.3 °C in January to a peak of 41.7 °C in May before gradually declining toward 29.1 °C in December. However, beyond seasonal regularity, recent years show amplification of extremes. Notably, May 2018 recorded 44.1 °C, June 2019 reached 43.0 °C, and May 2020 again touched 43.0 °C. These elevated peaks align with broader warming patterns documented by the Intergovernmental Panel on Climate Change (2021), which highlight increasing frequency and intensity of heatwaves globally. For Tharparkar’s agro-pastoral systems, such extremes intensify evapotranspiration, accelerate soil moisture depletion, reduce crop viability, and increase heat-related morbidity.

Minimum temperature patterns reveal equally significant variability. Annually minimum temperatures range from 17.5 °C to 19.9 °C. Winter months can be particularly cold, with January and December averages of 6.2 °C and 7.3 °C respectively. Extreme cold anomalies occurred in January 2007 and January 2014, with monthly averages dropping to between 2.9 °C and 4.5 °C. Conversely, summer nights provide limited thermal relief; June averages reach 27.1 °C. The coexistence of scorching daytime temperatures and warm nocturnal conditions during summer compounds cumulative heat stress, while cold winter nights affect livestock survival and crop germination. This broad diurnal and seasonal thermal amplitude test the adaptive thresholds of both ecosystems and human communities.

Relative humidity exhibits pronounced seasonal oscillation. Mean annual humidity ranged between 51% and 58%. The driest pre-monsoon months (March–April) recorded averages near 44%, intensifying aridity and dust generation. With monsoon onset, humidity rises sharply, peaking at 71% in August and 67% in September. Exceptional values were observed in August 2006 (78%) and September 2011 (81%). These rapid transitions from extreme dryness to high humidity alter perceived heat stress, influence vector ecology, and increase crop disease susceptibility.

Rainfall remains the most critical determinant of livelihood security. The 17-year mean annual rainfall was 376.1 mm, with nearly 90% concentrated in June–September. August is typically the wettest month (146.2 mm average). However, interannual variability is extreme: totals ranged from only 61 mm in 2018 to 1361.3 mm in 2011. Severe drought years, 2013 (191 mm), 2014 (208 mm), and especially 2018 (61 mm), demonstrate the volatility of monsoon dependence. Conversely, excessive rainfall generates flooding and infrastructure stress. This high variability, repeatedly highlighted by the Pakistan Meteorological Department, translates directly into food insecurity, livestock mortality, and groundwater instability.

Wind speed patterns further intensify environmental stress. Mean annual wind speed ranged between 4.8 and 7.3 knots, with the pre-monsoon and early monsoon period (May–July) being the windiest (9.5–10.3 knots). Extreme monthly values such as 16.7 knots in May 2008 reflect strong dust-raising winds that exacerbate soil erosion and increase evapotranspiration losses.

Finally, reference evapotranspiration (ETo), estimated via the MODIS MOD16 Penman–Monteith framework, ranged from 2336 mm to 2665 mm annually (2015–2020). This is approximately six to seven times the mean annual rainfall, underscoring a chronic hydrological deficit. Atmospheric water demand vastly exceeds precipitation supply, particularly in Dahli Taluka where ETo is highest. Even minor rainfall variability thus produces outsized ecological and economic impacts.

Collectively, the data confirm that Tharparkar’s climate system is defined not merely by aridity, but by volatility, thermal intensification, and a structural imbalance between water supply and atmospheric demand, conditions that necessitate urgent climate-resilient planning and adaptive resource management.

Escalating Climate Extremes and Socioeconomic Vulnerability

The long-term climatic record (2004–2020) for the Thar Desert in Pakistan presents compelling empirical evidence of a progressively harsher and more volatile environment. The data confirms a regime defined by four interlinked stressors. First, intensifying heat is evident in rising maximum temperatures and recurrent severe heatwaves, consistent with projections of the Intergovernmental Panel on Climate Change (2021). Summer peaks exceeding historical norms are no longer anomalies but recurring features, increasing thermal stress on crops, livestock, and human health.

Second, rainfall variability remains extreme. Although the mean annual rainfall appears moderate, the distribution is highly erratic. The catastrophic floods of 2011 contrast sharply with severe drought years such as 2013, 2014, and particularly 2018, when rainfall collapsed to critically low levels. Such oscillations validate findings by Usman and Nichol (2020) that drought frequency and intensity are increasing across arid Pakistan. For a region dependent on a short monsoon window, even minor rainfall deviations translate into disproportionate livelihood shocks.

Third, reference evapotranspiration (ETo) consistently exceeds rainfall by several multiples, generating a structural hydrological deficit. High pre-monsoon winds further accelerate soil moisture loss, intensifying water scarcity during critical cropping stages.

Finally, these stressors interact synergistically. Heat amplifies evaporation; drought reduces vegetative cover; wind accelerates land degradation. The cumulative outcome is declining soil fertility, reduced fodder availability, livestock mortality, and chronic food insecurity. In densely populated Tharparkar, climatic volatility directly converts into economic fragility and humanitarian risk.

Robust adaptation therefore demands evidence-based planning: drought-tolerant crop varieties, decentralized rainwater harvesting, strengthened early warning systems, and targeted social protection. As climate change accelerates, integrating long-term, ground-truthed climatic analysis into regional policy is not optional, it is indispensable for safeguarding livelihoods and ensuring ecological resilience.

Conclusion

The synthesis of long-term meteorological evidence from the Thar Desert, based on 2004–2020 data from the Pakistan Meteorological Department Mithi station, confirms that Tharparkar’s climate is undergoing measurable intensification in extremes rather than gradual linear change. Rising maximum temperatures, pronounced diurnal variability, erratic monsoon rainfall, high wind speeds, and exceptionally elevated reference evapotranspiration collectively define a system under structural hydrological stress. With atmospheric water demand exceeding annual rainfall by multiple folds, the region remains in a chronic water deficit, where even minor rainfall shocks translate into disproportionate socioeconomic consequences.

The evidence demonstrates that climatic volatility is directly linked to declining agricultural productivity, livestock vulnerability, soil degradation, and groundwater instability. For a densely populated arid zone heavily dependent on rain-fed agriculture, these dynamics magnify food insecurity, poverty risk, and climate-induced migration. The findings are consistent with broader warming projections highlighted by the Intergovernmental Panel on Climate Change, reinforcing that Tharparkar represents a frontline climate-sensitive region within Pakistan.

Moving forward, adaptation must be data-driven and region-specific. Climate-resilient crop planning, decentralized water harvesting, drought preparedness systems, and targeted social protection measures are not optional interventions but strategic necessities. Integrating long-term climatic diagnostics into provincial planning frameworks is essential to safeguard livelihoods, enhance ecological resilience, and secure sustainable development pathways in Thar.

References: IPCC; Meghwar et al.

Please note that the views expressed in this article are of the author and do not necessarily reflect the views or policies of any organization.

The writers are affiliated with the Drainage and Reclamation Institute of Pakistan (DRIP), Pakistan Council of Research in Water Resources (PCRWR) and can be reached at nazargul43@gmail.com

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