Climate Change and Agrarian Risk

Chapter 129 examines climate change as agrarian risk. The phrase matters. Farms do not experience a global mean-temperature curve directly; they experience heat during flowering, a delayed transplanting window, a dry canal, a waterlogged field, a failed fodder crop, a damaged road, a higher pump bill or a price shock after regional crop loss. Climate change alters the probability and intensity of some hazards, but economic loss appears through exposure and vulnerability created by landholding, irrigation, tenancy, credit, labour, seed systems, markets and public institutions. A social-economic history must therefore connect meteorology to the farm household rather than treating weather statistics as self-explanatory. The recent evidence is unusually instructive. The India Meteorological Department reported that 2025 was India's eighth warmest year since 1901, with annual mean land-surface air temperature 0.28°C above the 1991–2020 average and a long-run warming trend across 1901–2025. India as a whole received 110 per cent of its long-period annual rainfall, yet East and Northeast India received only 80 per cent of its long-period southwest-monsoon rainfall, and IMD's 2025 Standardized Precipitation Index showed extremely or severely dry conditions in parts of Bihar. This is exactly why national rainfall totals cannot stand in for agrarian water conditions in Mithila, Vajji or Anga. Across the border, Madhesh Province in Nepal experienced a severe 2025 drought. ICIMOD's rapid analysis estimated rainfall deficits of roughly 30–50 per cent, widespread groundwater stress and delayed rice transplantation—about 52 per cent completed compared with about 92 per cent at the same time a year earlier—together with a potential rice shortfall. ADB subsequently identified the delayed Madhesh monsoon, along with October flood damage elsewhere, as a factor reducing paddy output and pressuring food prices. These episodes do not by themselves prove that every component was caused by anthropogenic climate change. They demonstrate the kind of compound agrarian risk that a warming climate, variable monsoon, water dependence and unequal adaptive capacity make economically consequential. 129.1 Climate change as agrarian risk, not a weather slogan The analytical starting point is to separate climate, weather and agrarian risk. Climate describes statistical patterns over long periods; weather is the event or season experienced now; agrarian risk is the possibility that those conditions produce economic or social loss. A heat wave matters differently to fallow land, flowering wheat, a dairy herd and a household with no irrigation. A monsoon deficit matters differently where a reliable canal exists than where a tenant depends on a costly diesel pump. The region's future cannot therefore be read from temperature or rainfall alone. The central historical question is how older institutions—fragmented holdings, tenancy, river-control systems, groundwater development, migration and public extension—mediate newer climatic pressures. 129.2 Hazard × exposure × vulnerability A useful risk framework treats loss as the interaction of hazard, exposure and vulnerability. Hazard is the physical event or trend: heat, drought, intense rainfall, flood, waterlogging or a damaging sequence. Exposure asks what lies in its path and at what crop stage. Vulnerability asks how sensitive the exposed system is and how much capacity exists to cope or adapt. A short dry spell during a robust vegetative stage may have little effect; the same dry spell at transplanting or flowering can be decisive. A wealthy farmer with assured irrigation can absorb a pump repair; a marginal tenant may miss the entire planting window. This framework prevents 'climate' from becoming a blanket explanation for outcomes produced jointly by environment and social structure. HISTORY OF MITHILA, VAJJI & ANGA — VOLUME II 129.3 Attribution: what can and cannot be claimed The scientific literature establishes that human-caused climate change has warmed the atmosphere and increased the likelihood or severity of several kinds of extremes, including heat. It does not follow that every local drought, flood or crop failure can be attributed to climate change without an event-specific analysis. Monsoon variability is shaped by multiple atmospheric and oceanic processes; river floods also depend on catchment rainfall, siltation, embankments, drainage and settlement; crop losses depend on planting date, variety and management. This chapter therefore uses climate change as a changing risk background and uses observed events as examples of vulnerability. Where no formal attribution study exists, the wording remains 'consistent with', 'occurred under', or 'illustrates' rather than 'was caused by'. 129.4 A warming baseline over the Indo-Gangetic and Terai plains IMD's 2025 climate statement places the recent year within a longer warming record: India's annual mean temperature trend over 1901–2025 is positive, and 2024 remains the warmest year in the national series. Regional farms experience this background through hotter days and nights, higher evaporative demand and altered heat exposure for labour, crops and livestock. The Gangetic and Terai plains are not climatically uniform, but low elevation, dense settlement and intensive cropping make heat economically important. Higher temperatures can shorten crop development, increase irrigation demand and reduce safe outdoor labour hours. The historical significance is cumulative: a production system calibrated to older seasonal expectations must increasingly manage heat even in years when rainfall appears adequate. Figure 512 — Agrarian climate risk emerges through a chain linking hazard, exposure, vulnerability, loss and response; adaptation changes the chain but cannot remove all residual risk. 129.5 Monsoon dependence and intra-seasonal variability Total monsoon rainfall is only one agronomic variable. Farmers also need onset timing, the distribution of rainy days, breaks between spells and rain intensity. Rice nurseries and transplanting depend on water at a narrow calendar stage; prolonged rain after sowing can be as damaging as deficit; intense rainfall may run off rather than recharge soil moisture. Cropping decisions are therefore sensitive to intra-seasonal variability. This is one reason district and block-level advisories matter more than a national seasonal headline. The economic risk rises when farmers must purchase seed, hire labour or rent pumps before they know whether the next critical rainfall window will arrive. Climate uncertainty thus interacts directly with working-capital decisions. 13231323 GAJENDRA THAKUR 129.6 A wet region can still experience agricultural drought Mithila and the north Bihar plains are widely associated with floods, yet drought and moisture stress are persistent parts of the agrarian system. Agricultural drought is not the simple opposite of flood history. A field can face delayed monsoon water in June and July and destructive inundation later in the season. Upland plots may dry while nearby lowlands waterlog. Canal or groundwater access may protect one village while another depends almost entirely on rain. The coexistence of flood and drought risk explains why climate resilience cannot be reduced either to embankments or to more pumping. Water must be available when crops need it and safely drained when it is excessive. Chapter 130 examines flood adaptation in detail; here flood is treated as one element in a wider risk portfolio. 129.7 2025 in India: above-normal national rain, regional dryness The 2025 season provides a compact warning against spatial averaging. IMD reported 1,274 mm of annual rainfall for India, about 110 per cent of the 1971–2020 long-period average. Yet East and Northeast India received only 80 per cent of its long-period southwest-monsoon rainfall. The annual Standardized Precipitation Index also showed extremely or severely dry conditions in parts of Bihar. These measures are not interchangeable: one is an all-India total, one a broad regional monsoon statistic and one a spatial drought indicator. Together they show why agrarian analysis must move downscale. A farmer's crop calendar can fail in a year that looks 'wet' in the national aggregate. 129.8 2025 Madhesh drought as a crop-calendar shock The 2025 Madhesh drought shows the economic force of timing. ICIMOD's rapid situational analysis reported deficient winter rain followed by weak monsoon performance, rainfall deficits of roughly 30–50 per cent, groundwater and borehole stress, and severe disruption to rice transplantation. By late July only about 52 per cent of rice land had reportedly been transplanted compared with about 92 per cent in the corresponding 2024 period. A delay at this stage propagates: nursery age changes, labour peaks shift, harvest is pushed later and the following rabi crop may be delayed. The shock is therefore not only lower rainfall; it is a compressed sequence of lost agricultural options. 129.9 Rice transplantation and the narrowing planting window Transplanted rice is calendar-sensitive because nursery preparation, puddling, labour, standing water and field conditions must align. Delayed transplanting can force farmers toward older seedlings, shorter-duration varieties or direct seeding; it can also push harvest into a period that conflicts with wheat or maize establishment. Smallholders face especially hard choices when seed has already been purchased and labour arranged. ICAR's recent Bihar outreach has stressed timely crop establishment, short-duration rice where planting is delayed and direct-seeded rice under suitable conditions. These are not universal prescriptions. Soil type, weed control, water availability and farmer skill determine whether a technique works. Resilience comes from a menu of feasible options linked to real-time advisories, not from one promoted technology. HISTORY OF MITHILA, VAJJI & ANGA — VOLUME II Figure 513 — Illustrative seasonal risk calendar: heat, water deficit and excess-water hazards overlap differently with rice, wheat, maize, livestock and water availability. 129.10 Terminal heat and wheat Wheat is exposed to a different climate pathway. Much of the risk comes late in the season when rising spring temperatures can accelerate development during grain filling. The effect depends strongly on sowing date and variety. A delayed rice harvest can therefore create a cross-season cascade: late wheat establishment increases the chance that sensitive stages coincide with hotter weather. Research in Bihar has explicitly examined late-sown wheat and terminal heat as a production problem. Adaptation begins before the heat event—through timely rice harvest, suitable wheat varieties, seed access and machinery that allows rapid establishment. The rice-wheat system thus shows why climate risk cannot be analysed crop by crop in isolation. 129.11 Maize, pulses and crop-specific stress pathways Maize and pulses diversify income and can fit into changing calendars, but they bring their own sensitivities. Maize can suffer from waterlogging as well as drought, and reproductive stages are sensitive to heat and moisture stress. Pulses often use less water than paddy but can be damaged by untimely rain, humidity or disease during flowering and harvest. Bihar Agricultural University and ICAR programmes have therefore worked on stress-tolerant varieties, crop diversification and location-specific agronomy rather than assuming that a single 'climate-smart crop' exists. Diversification is valuable because different crops fail under different conditions; its insurance value declines if all components share the same hazard exposure or market bottleneck. 129.12 Flood, waterlogging and submergence as yield risk Excess water remains fundamental to northern Bihar and parts of the Nepal Terai. Submergence can destroy seedlings, waterlogging can reduce root oxygen, and prolonged inundation can delay replanting after the nominal flood has receded. Roads, storage and input delivery may be disrupted even where the standing crop survives. Farmers historically respond through crop choice, raised storage, livestock movement, flexible calendars and repeated sowing, while public policy adds embankments, drainage and relief. The difficulty is 13251325 GAJENDRA THAKUR that flood control itself can redistribute risk between places and times. Because those institutional and engineering questions deserve separate treatment, Chapter 130 examines flood adaptation and resilience directly. Chapter 129 treats excess water mainly as a competing climate hazard that must be managed alongside drought. 129.13 Groundwater: adaptation buffer and depletion risk Groundwater is one of the most important buffers against rainfall failure because it lets farmers separate crop water from the exact timing of monsoon rain. But the buffer is not free. Wells require capital, pumps require electricity or fuel, aquifers require recharge and access is unequal. The 2025 Madhesh drought demonstrated how groundwater stress can intensify when weak winter rain and monsoon deficit coincide; ICIMOD reported that more than 30 per cent of boreholes were dry in affected areas. In Bihar, ICAR has also identified declining groundwater levels, irrigation energy cost and inefficient water application as current challenges. Climate adaptation that simply increases extraction can therefore shift risk into the future unless paired with recharge, efficient irrigation, surface-water management and monitoring. 129.14 Irrigation reliability, energy and unequal access Irrigation statistics can overstate resilience if they count infrastructure without asking whether water arrives reliably, affordably and at the right time. A tubewell with an unreliable power supply, a canal with uncertain release or a pump that a tenant cannot afford may exist on paper while the crop remains exposed. Energy pricing also shapes water use: cheap power can support timely irrigation but encourage over-pumping where groundwater is scarce. Solar pumps lower operating costs yet need governance for the same reason. Adaptation should therefore measure service quality—hours of supply, depth to water, cost per irrigation, tail-end access and emergency availability—not merely installed capacity. Unequal irrigation access is one of the main mechanisms by which the same drought becomes unequal household loss. 129.15 Soil moisture, soil health and climate sensitivity Soil is the first water reservoir available to a crop. Organic matter, texture, compaction, drainage and field levelling influence whether rainfall is stored, lost as runoff or trapped as damaging waterlogging. Climate- resilient agriculture therefore overlaps strongly with ordinary agronomy: balanced nutrients, residue management, green manuring, legumes, conservation practices and soil-test-based management can improve rooting and water-use efficiency. Recent ICAR programmes in Bihar have promoted these measures alongside direct-seeded rice and crop diversification. Their value should not be romanticized as immunity to drought. Healthy soil can buffer short stress and improve efficiency, but severe rainfall failure still requires water, crop adjustment or income support. Resilience is incremental, not absolute. 129.16 Pests, diseases and ecological uncertainty Temperature, humidity and rainfall affect pests and crop diseases, but outcomes are biologically complex. A warmer or wetter season can favour one organism while suppressing another; changing crop calendars alter host availability; pesticide practices alter resistance and beneficial insects. Climate narratives sometimes exaggerate by attributing every outbreak to warming. The safer economic approach is surveillance. Integrated pest-management systems, field scouting, diagnostic laboratories and timely advisories reduce the chance that an emerging outbreak becomes a large loss. Seed systems also matter because disease-resistant varieties and replacement seed must reach farmers before the relevant planting window. Climate resilience therefore includes ecological information infrastructure, not only physical irrigation. HISTORY OF MITHILA, VAJJI & ANGA — VOLUME II 129.17 Livestock heat, fodder and water stress Livestock convert crop residues, fodder and household labour into milk, traction, manure and a liquid asset. Heat raises drinking-water needs and can reduce feed intake, fertility and milk production, while drought reduces fodder availability. Floods can isolate animals from veterinary services and dry shelter. Small dairy households may experience a compound shock when crop residues fall at the same time purchased feed becomes more expensive. Heat adaptation includes shade, ventilation, reliable water, adjusted feeding times, fodder reserves and breed-specific management. The household economy matters because women often perform much of the daily livestock care. A climate shock that leaves animal ownership unchanged can still increase unpaid labour and reduce marketed milk. 129.18 Fisheries, ponds and aquaculture risk Ponds, wetlands and aquaculture diversify rural income in a region rich in water bodies, but they are climate-sensitive assets. High temperature can reduce dissolved oxygen; drought can shrink ponds and concentrate fish; intense rainfall or flood can cause overtopping and stock escape; polluted runoff can damage water quality. Fish culture therefore requires water-depth management, embankment maintenance, stocking decisions and access to timely advisories. The risk profile differs from field crops: a pond may benefit from rainfall that waterlogs paddy, yet fail under prolonged heat and low water. Integrated farming systems can spread household risk precisely because components respond differently, provided one hazard does not simultaneously destroy all connections. Figure 514 — The 2025 Bihar–Madhesh warning: national or broad-regional rainfall totals must not be treated as farm-level water conditions; timing and local distribution drive crop-calendar risk. 129.19 Horticulture and high-value crops Vegetables, fruits, spices and flowers can raise returns per unit of land and suit small holdings, but higher value often comes with higher sensitivity to timing and quality. Heat can reduce flowering or fruit set, rain can spoil harvest, and interrupted roads or electricity can destroy value after production. Perishable crops therefore expose farmers to climate risk in transport, storage and markets as well as in fields. Adaptation requires shade or protected cultivation where economic, drainage, irrigation, short supply chains, cold-chain options and market information. Diversification into high-value agriculture is not automatically risk reduction; it changes the composition of risk from bulk yield toward quality, logistics and price. 13271327 GAJENDRA THAKUR 129.20 Small holdings and limited shock-absorption capacity Land fragmentation, examined earlier in PART XIII, amplifies climate risk because small plots limit economies of scale and leave little physical room for spreading production across soils or micro-elevations. More important, small farms often operate with thin savings. A failed crop may consume the capital needed for the next season, turning one weather shock into several years of constrained investment. Yet small size does not imply passive vulnerability. Intensive horticulture, livestock, migration income and collective irrigation can all raise resilience. The policy error is to treat farm size as destiny. What matters is the bundle of assets, income sources, institutions and services available to the household when a critical crop window fails. 129.21 Tenancy, landlessness and who carries crop loss Climate losses are distributed through contracts as well as fields. A sharecropper may lose labour and input expenditure while owing a share of output or rent; a cash tenant may bear production risk on land whose owner retains the asset; a landless worker may lose wages when transplanting or harvesting demand collapses. Official crop-loss estimates centred on ownership can therefore miss large parts of the rural economy. Compensation, insurance and credit systems need to identify actual cultivators without creating perverse documentation burdens. The historical point is that agrarian vulnerability is a relation between people, not simply a map of damaged hectares. Climate change intensifies the stakes of long-standing debates over tenancy recognition and social protection. 129.22 Gendered labour, water and care burdens Climate shocks redistribute labour within households. When water becomes scarce, collection and livestock care may take longer; when men migrate, women may manage crop decisions while still facing weaker access to land titles, formal credit, extension meetings or machinery. Heat also changes safe working hours, and the agricultural calendar may collide more sharply with domestic care. Recent ICAR programmes in Bihar have explicitly included women farmers in soil, water and diversified homestead-farming training, which is important because resilience technologies are ineffective if they reach only nominal male landholders. Gender-responsive adaptation should therefore measure control over income, access to advisories and assets, and time burden—not only attendance at training. 129.23 Migration and remittances as risk-sharing—and fragility Migration can function as informal climate insurance. Income earned outside agriculture may finance irrigation, replace a failed harvest, pay school fees and prevent distress sale of assets. The earlier chapters on migration and remittances showed how central these flows are to Mithila and neighbouring regions. But dependence on migration can also create fragility. Labour shortages can make time-sensitive farm operations more expensive; destination shocks can reduce remittances just when a crop fails; and households may invest less in agriculture if returns appear persistently risky. Climate change therefore interacts with an already mobile economy. The key question is whether migration expands household choice or becomes the only viable response to repeated agrarian stress. 129.24 Prices, food security and household nutrition A crop shock is transmitted beyond producing households through prices. Reduced paddy output can raise local rice prices; fodder scarcity can raise milk costs; damaged roads can widen the gap between farm- gate and retail prices. ADB's December 2025 Nepal update linked the delayed monsoon in Madhesh and flood damage to weaker paddy output and food-price pressure. Price effects are not uniform: a net-selling HISTORY OF MITHILA, VAJJI & ANGA — VOLUME II farmer may gain from higher prices if enough crop survives, while a net-buying smallholder or landless household loses. Food security analysis must therefore distinguish production from entitlement. Nutrition may deteriorate even where calorie staples remain available if households cut vegetables, pulses, milk or animal protein to protect cash. 129.25 Weather advisories and the last mile Forecasts have economic value only when they arrive in time, at a usable spatial scale and in language that connects to a decision. A rainfall probability is useful if a farmer knows whether to transplant, spray, irrigate or harvest. Advisories therefore need crop stage, local soil context and clear uncertainty. Bihar Agricultural University and ICAR programmes include weather advisories, contingency planning and climate-resilient management within their research and extension architecture. The last mile is not merely a smartphone problem. Tenant cultivators, women, older farmers and people with weak connectivity may receive information differently. The quality of an advisory system should be evaluated by decision change and avoided loss, not by the number of messages sent. 129.26 Stress-tolerant seed and crop-calendar adaptation Seed is one of the fastest ways to alter biological exposure. Short-duration rice can help recover from delayed monsoon onset; submergence-tolerant, drought-tolerant or heat-tolerant material can reduce losses under particular stresses; maize and pulse breeding can expand options. But a variety is only useful if seed is available in sufficient quantity at the moment a contingency decision is made. Replacement seed after a failed nursery may be more important than the annual sale of normal seed months earlier. Climate adaptation therefore requires a responsive seed system with local multiplication, quality assurance and contingency inventories. It also requires realism: tolerance reduces sensitivity within a range; it does not make crops invulnerable to extreme or prolonged conditions. 129.27 Diversification, integrated farming and water-smart systems ICAR's recent Bihar work has emphasized millets, water-smart farming, crop diversification and integrated farming systems. The economic logic is portfolio diversification. Rice, pulses, vegetables, livestock, fish and off-farm income respond differently to hazards and market conditions, so a household need not depend on one harvest. Integration can also recycle nutrients and residues. Yet complexity imposes management and labour demands. A diversified farm with unreliable veterinary services, no vegetable market and insufficient water may carry more, not less, operational risk. The best portfolio is therefore location- specific and household-specific. Public programmes should provide modular options and market connections rather than prescribing the same integrated model to every farmer. 129.28 Insurance, credit and basis risk Insurance and credit can smooth climate shocks, but their design determines whether they reduce or compound distress. Weather-index insurance may pay quickly but can create basis risk when the index does not match a particular farm's loss. Yield-based systems may reflect crop damage better but require reliable estimation and timely claims processing. Credit is essential for replanting, irrigation repair or fodder purchase, yet new debt after a failed season can become a trap if the next crop also fails. Financial resilience therefore needs transparent triggers, cultivator inclusion, grievance systems, rapid payment and links to agronomic contingency plans. The chapter does not use enrolment headlines as evidence of effectiveness; evaluation requires household-level claim, timing and loss data. 13291329 GAJENDRA THAKUR 129.29 What climate-resilient agriculture should mean here Climate-resilient agriculture in Mithila, Vajji, Anga and Madhesh should be understood as a portfolio of capacities rather than a branded package. It includes stress-tolerant and short-duration seed, flexible crop calendars, soil-water management, reliable but sustainable irrigation, drainage, diversified farm and non-farm income, livestock and fishery protection, weather advisories, responsive extension, credit, insurance and social protection. It also includes institutions capable of learning from failure. Nepal's National Adaptation Plan 2021–2050 and active NDC 3.0, and Bihar's climate-resilience consultations and research programmes, provide policy frameworks; their effectiveness will be visible only in local water security, reduced loss and more equal adaptive capacity. Resilience is the ability to preserve options under uncertainty. Figure 515 — Climate resilience is a portfolio: seed, calendar, water, soil, diversification, forecasts and finance must work around the farm household and its institutional access. 129.30 From agrarian climate risk to flood resilience The central conclusion is that climate change does not replace the region's older agrarian history; it works through it. Riverine ecology, land fragmentation, irrigation inequality, tenancy, migration, gendered labour and market integration determine how temperature and rainfall become household outcomes. The 2025 Bihar and Madhesh evidence illustrates spatially uneven drought within a monsoon system better known publicly for floods. At the same time, excess rainfall and river inundation remain recurrent threats. The next chapter therefore narrows the lens to flood adaptation and resilience: embankments and their externalities, drainage, forecasting, settlement, crop strategy, relief, insurance, infrastructure and the problem of living with rivers rather than treating each flood as an isolated emergency. HISTORY OF MITHILA, VAJJI & ANGA — VOLUME II Table 129.1 — Evidence architecture for analysing climate change and agrarian risk Evidence source What it measures Decision / historical use Main limitation Station / gridded temperature, rainfall hazard baseline and crop- station gaps and weather timing, intensity and stage exposure spatial averaging can dry spells hide local extremes SPI / drought index standardized moisture compare dryness across index choice may not anomaly over a chosen time and place match crop-root-zone period water Crop area / yield sown area, harvested estimate production administrative revision statistics area and output impact and weak sub-district resolution Crop-cutting field-level yield estimate loss assessment and sampling and timing experiment insurance quality vary Remote sensing vegetation, water rapid spatial monitoring needs ground extent, crop condition validation; clouds and and planting progress mixed pixels can interfere Groundwater water level, drawdown irrigation-buffer well network may not monitoring and seasonal recharge sustainability represent farmer access or pump cost Canal / irrigation release timing, reliability of water access installed capacity is service record command-area supply, not delivered service breakdowns Market price series farm-gate / wholesale / food-price transmission confounded by trade, retail price movement after shocks policy and non- climate supply changes Household panel / assets, tenancy, income, vulnerability and recall bias and survey migration, coping and distributional effects attrition nutrition Insurance / credit claims, payouts, loan financial protection after coverage excludes records restructuring and loss many cultivators; timing claims are not total damage Advisory / forecast forecast skill, message value of climate services message delivery does verification timing and farmer not prove decision use response Qualitative crop local thresholds, labour interpret why timing not a substitute for calendar bottlenecks and farmer mattered measured meteorology memory or yield data 13311331