When the Climate Outgrows the Crop
Every plant has a temperature envelope and a chilling-hour budget. I have mapped Himachal's full produce portfolio against its crop hardiness requirements and the state's projected warming. The result is a clear ranking of what the climate will break first, what it will not break, and what it will quietly favour.
Himachal Pradesh's climate modelling projects an annual mean temperature increase of 1.3 to 1.9 degrees Celsius for 2021-2050 against the 1971-2000 baseline, with a larger rise in minimum temperatures (Report on Climate Modelling, HP Department of Environment, Science and Technology). Under IPCC high-emission scenarios, India's near-term warming is projected at 0.5 to 2 degrees Celsius by 2049. CMIP6 projections specific to Himachal indicate that heatwave frequency and intensity increase with altitude, contrary to the assumption that higher elevations are protected (Rana et al., Environmental Quality Management, 2025). Apple requires 1,000 to 1,600 chilling hours below 7 degrees Celsius to fruit. Tea yields fall 4 percent for every 1 degree above 28 degrees Celsius. Saffron requires 1,000 to 1,200 chilling hours below 4 degrees Celsius for vernalisation. These are not adjustable parameters.
The Himalayan climate story is often told as one of retreating snow and melting glaciers. That framing is correct but incomplete. The economic mechanism by which warming converts into livelihood loss runs through crop hardiness: the non-negotiable temperature and chilling requirements that each species evolved to need. When a warming trajectory crosses a hardiness threshold, the crop does not yield a little less. It stops yielding usefully.
Himachal Pradesh is a useful test case because its produce portfolio spans almost the entire range of temperate and subtropical agriculture in a single state: apples that need nearly freezing winters, saffron that needs high-altitude cold deserts, tea that needs temperate humidity, off-season vegetables that exploit the very specific summer window when the plains cannot grow them, livestock systems that follow transhumance patterns tied to alpine meadow cycles. Every one of these systems has a hardiness limit that is now being tested.
I have cross-linked each major produce category from our earlier map against three things: its chilling hour or temperature requirement, Himachal's current position relative to that requirement, and the projected shift by 2030 and 2050. The matrix below is deliberately unsparing. It is not a forecast of catastrophe. It is an honest mapping of which parts of the produce economy are already at or past their hardiness threshold, which are in the transition zone, and which have headroom.
Three parameters determine whether a produce category is climate-resilient, at threshold, or in collapse.
The key scientific point is that these three parameters operate as hard floors and ceilings, not smooth gradients. A small excursion past threshold does not produce a proportional yield drop. It produces a step change. This is why the apple belt did not gradually thin in lower Kullu and Shimla over two decades; it collapsed, while new planting migrated 1,000 metres uphill into Lahaul-Spiti. The underlying signal is sharp even when the aggregate numbers look smooth.
| Produce | Hardiness requirement | Current HP fit | Projected shift by 2050 | Risk tier |
|---|---|---|---|---|
| AppleTraditional varieties | 1,000 - 1,600 chill hours below 7 degrees Celsius. USDA hardiness zones 4 to 8b. | Below 1,500 m now sub-threshold. Mid-elevation belt losing 25 to 40 percent yield. | Lower and mid belt (Solan, Sirmaur, Kullu valley floor) unviable. Commercial apples retreat to above 2,500 m. | Critical |
| Stone fruitsPlum, peach, apricot, cherry | 400 - 1,050 chill hours depending on variety. High-chill varieties match apple threshold. | Most high-chill cultivars under stress; low-chill varieties (under 400 hours) still viable in lower belts. | High-chill stone fruits follow apple uphill. Low-chill varieties expand in lower Kullu and Mandi. | High |
| Walnut, almondNuts and dry fruits | Walnut 700-1,000 chill hours. Almond 100-500. High altitude tolerant. | Walnut under stress in mid Kullu; almond holding in Kinnaur and Chamba. | Walnut belt contracts; almond less exposed. Both can migrate upslope. | High |
| Kangra teaCamellia sinensis | Optimal 21-29 degrees Celsius. Yield drops 4 percent per 1 degree above 28. Needs high humidity, pH 4.5-6.5. | Kangra valley summer temperatures already approach ceiling; monsoon variability a growing risk. | Yield compression of 6-12 percent. Quality shifts (higher catechin stress markers). Pest pressure rises. | High |
| SaffronKesar, recent pilots | 1,000 - 1,200 chill hours below 4 degrees Celsius for vernalisation. Flowers at 17 degrees. | Pilots across Kinnaur, Bharmour, Lahaul-Spiti meet threshold. Palampur and Kullu marginal. | High-altitude pilot sites remain viable. Mid-elevation pilots (Kullu, Palampur) become sub-threshold. | Moderate |
| Citrus, mangoSubtropical fruits | Citrus: less than 300 chill hours, frost-sensitive. Mango: 24-30 degrees Celsius optimal. | Warming is presently favourable for the lower hill belt (Kangra, Una, Bilaspur). | Cultivation zone expands upslope into former apple territory. Pest and disease pressure rises. | Net beneficiary |
| Off-season vegetablesTomato, peas, cabbage, cauliflower | Cool-season window (June-Sep) when plains are too hot. Peas need 10-18 degrees. Tomato fruit set fails above 32. | The window is narrowing at both ends. Unseasonal monsoon spikes have hit Kullu and Mandi production hard. | The "off-season" premium window compresses by 3-5 weeks. Net returns compress by 15-25 percent. | High |
| Seed potatoLahaul, upper Shimla, Kinnaur | Tuber formation optimal at 15-20 degrees Celsius. Requires cool nights (below 15) for tuberisation. | High-altitude production zones still viable. Low-elevation seed multiplication losing reliability. | Seed potato quality migrates fully into Lahaul-Spiti and upper Kinnaur by 2050. | Moderate |
| CerealsWheat, maize, rice | Wheat: yield loss of 6 percent per 1 degree above optimal grain-fill temperature. Maize and rice more heat-tolerant. | Indo-Gangetic wheat yields already reduced by about 8 percent. Himachal cereals follow the same pattern. | Yield compression of 10-18 percent for wheat. Maize and rice marginal impact. | Moderate |
| Ginger, turmeric, garlicRhizomatous spices | Ginger: 25-30 degrees Celsius, high humidity, well-drained soil. Turmeric similar. Garlic needs cool maturation. | Kangra, Sirmaur, Mandi currently near optimal. Garlic facing declining chilling. | Ginger and turmeric stable to slightly favoured. Garlic belt migrates upslope. | Stable |
| Himachali kala zeeraBunium persicum | Native to 1,850-3,100 m. Cold-hardy, drought-tolerant. Requires dry summer harvest window. | Current range remains climatically suitable. Dry harvest windows holding. | Range may shrink at lower elevations (1,850 m) but expands at upper end. Net neutral. | Stable |
| Heeng, hopsLahaul-Spiti pilots | Heeng: cold, dry, high altitude. Hops: 4-8 hours frost tolerance, moderate summer heat. | Lahaul-Spiti conditions ideal; pilot sites match native climate envelopes. | Both remain viable in high-altitude pilot zones through 2050 under moderate warming scenarios. | Stable |
| Medicinal plants640 native species | Diverse envelopes. Alpine species (above 2,500 m) most climate-sensitive. Subtropical species more tolerant. | Alpine species facing habitat compression. Mid-elevation species shifting upslope. | Estimated 20-35 percent of alpine medicinal species face range loss by 2050. Subtropical species expand. | High |
| Industrial hempLow-THC cultivars | Wide thermal envelope (15-27 degrees Celsius optimal). Low water requirement. Tolerant of temperature variability. | Virtually all HP elevations below 2,500 m climatically suitable. | Remains viable across the widest elevation band of any commercial crop. Actively favoured as other crops retreat. | Net beneficiary |
| Dairy (milk)Statewide | Heat stress in dairy cattle above 25-27 degrees Celsius reduces milk yield 10-25 percent. | Mid and lower hill dairy already exposed to summer heat stress. Fodder scarcity follows drought. | Yield compression of 8-15 percent without intervention. Shift toward heat-tolerant breeds and housed systems. | High |
| Gaddi wool, pashminaMigratory livestock | Transhumance depends on alpine meadow cycles. Pashmina goats need cold winters for fibre development. | Alpine grazing seasons shortening; Gaddi pastoralists reporting reduced water along migration routes. | Alpine pasture productivity may shift but remains functional. Pashmina fibre quality at risk in warming trans-Himalaya. | High |
| TroutRainbow and brown | Optimal 10-16 degrees Celsius water temperature. Thermal stress above 18, lethal above 22. | Kullu, Mandi, Chamba stream temperatures rising in summer months. Marginal conditions now documented. | Lower-elevation trout farms become thermally unviable in summer. Production migrates upstream to cold tributaries. | Critical |
The matrix above collapses into four operationally useful tiers. These are not a ranking of which crops I like; they are a ranking of how much climate adaptation capital each segment requires, and over what timescale.
The crops already breaking
The lower-elevation apple belt in Solan, Sirmaur and lower Kullu has effectively lost commercial viability. Traditional varieties needing 1,000 to 1,600 chilling hours cannot accumulate them at elevations below 1,500 metres. Yield losses of 25 to 40 percent in traditional belts, with production migrating 1,000 metres upslope into Lahaul-Spiti. Trout farms in Kullu, Mandi and Chamba report summer stream temperatures approaching the 18 degree Celsius thermal stress threshold, with lethal conditions above 22. The investment implication is that defending these crops in their current locations is not the right strategy. Capital should be routed to upslope relocation, low-chill varietal substitution, and alternative uses for former orchard land.
The crops where adaptation still works
This tier represents the bulk of Himachal's produce economy by value. Off-season vegetables (Rs 16,076 crore annual output) depend on a summer window that is compressing at both ends as the plains stay hot later into autumn and Himachal's summer heats earlier. Kangra tea is already measuring yield loss at every degree above the 28 degree Celsius ceiling. Dairy production faces heat stress compression of 8 to 15 percent without intervention. Alpine medicinal plant species face range loss estimated at 20 to 35 percent by 2050 (ICAR and CSIR-IHBT literature). The investment implication is that adaptation pathways exist but require active management. Shade netting, drip irrigation, heat-tolerant cultivars, shift to high-density planting, housed dairy systems, and protected cultivation of medicinal species.
The crops that migrate within the state
These crops have partial exposure at lower elevations but viable refugia at higher ones. Seed potato production is already consolidating into Lahaul-Spiti and upper Kinnaur. Saffron pilots in Kinnaur and Bharmour (above 2,000 m) meet the 1,000 to 1,200 chilling hour threshold; lower-elevation pilots in Palampur and Kullu do not. Himachali kala zeera, heeng and hops are native or well-suited to the trans-Himalayan cold desert belt and remain viable through 2050 under moderate warming. The investment implication is that these are the crops state agricultural policy should actively promote in the diversification portfolio, because they are genuinely climate-compatible with Himachal's future.
The crops where warming is a tailwind
Not every produce category loses. Citrus, mango and subtropical fruits in Kangra, Una and Bilaspur are currently in their optimal thermal envelope, and warming expands their viable zone upslope into former apple territory. Industrial hemp, legalised in September 2024 with a pilot licensing framework in 2026, has one of the widest thermal envelopes of any commercial crop and is genuinely climate-resilient. Low-chill fruit varieties (under 400 chilling hours) can replace high-chill apple and stone fruit in mid-elevation belts. The investment implication is that Himachal's diversification play is not just defensive. There is a genuine upside in the low-elevation subtropical expansion and in hemp, both of which map directly to the climate trajectory rather than fighting it.
How to read this portfolio under climate stress
Three observations compress the analysis into something boards and investors can actually act on.
First, Himachal is not losing its produce economy. It is losing its current produce geography. Every crop category still exists somewhere in the state at 2050. Apples still exist, just 1,000 metres higher. Trout still exists, just in colder tributaries. Alpine medicinal plants still exist, just with smaller ranges. The planning challenge is not "how do we save the apple" but "how do we manage an orderly climate-driven migration of the produce economy". This is an infrastructure, land-use and capital-deployment problem, not an agricultural one.
Second, the single-commodity story is the wrong story. Apple dominates the narrative because it dominates the headline economics and the political voice of the state. But the matrix above shows that the climate-resilient segments (saffron, heeng, hops, kala zeera, hemp, medicinal plants, low-elevation subtropical fruits) collectively represent a larger theoretical Rs-per-hectare opportunity than the incremental defence of apple at lower elevations. The HP State Cabinet's January 2025 cannabis pilot approval and the ongoing CSIR-IHBT aromatic crops mission are precisely this strategy. They are not diversification against apple; they are climate repositioning of the whole produce portfolio.
Third, the crops in Tier 02 are where policy can still make a material difference. Tier 01 is largely a transition problem. Tier 04 will adapt itself given licensing and market linkages. Tier 02, the off-season vegetables, tea, dairy and stone fruits, sits on the decision margin where incremental adaptation capital (shade structures, cold chain, protected cultivation, heat-tolerant livestock breeds, irrigation storage, pest and disease surveillance) translates directly into preserved yield and preserved livelihoods. This is where the state's climate adaptation budget and development finance institutional capital should concentrate.
The broader implication for Indian climate investment
Himachal is a microcosm of what will play out across India's entire temperate and subtropical agriculture belt. The Kashmir saffron industry, the Darjeeling tea industry, Uttarakhand's apple and pear belt, the Nilgiris tea estates, and Sikkim's large cardamom all face versions of the same crop-hardiness squeeze. The investors and DFIs who build frameworks now for evaluating agri-climate exposure at the crop-hardiness level, rather than at the broad sector level, will price risk more accurately than those still using aggregated GDP figures.
That framework is what I have tried to lay out above. It is deliberately unsentimental about which crops can be defended and which cannot. It is equally deliberate about identifying the categories that are genuinely climate-resilient and under-invested. The Himachal Pradesh produce economy through 2050 will be smaller in some categories and larger in others. Whether it ends up net expanded or net compressed is a function of how well the policy and capital decisions of the next decade match the hardiness map.