Climate Change and Kerala’s Agriculture Scenario

Climate Change has become a critical environmental issue due to the rise in atmospheric temperature from increased greenhouse gases like CO2, CH4, N2O, and HCFCs. The escalating greenhouse gas concentrations raise concerns about future climate changes across various systems such as the atmosphere, lithosphere, biosphere, hydrosphere, and cryosphere. The repercussions on sectors like water, forestry, agriculture, animal agriculture, fisheries, biodiversity, and health are significant, with a vast economic impact. Recurrent droughts and desertification threaten over 1.2 billion people reliant on land, and the global economy suffers from extreme weather events, forest fires, landslides, and sea-level rise. Human activities have significantly contributed to global warming and climate change through increased emissions, deforestation, land-use changes, forest fires, and loss of wetlands. The rise in aerosols,depletion of ozone, and human-induced deforestation and wetland loss are key factors in climate variability. CO2 levels, stable at 280 ppm until 1850, have surged to about 421 ppm due to industrialization and fossil fuel combustion. The increase in CO2 is mainly from fossil fuel use and land use changes, with deforestation and wetland loss disrupting rainfall absorption, leading to erosion, floods, droughts, and faster soil drying during dry periods. Changes in rainfall and temperature, occurrences of extreme weather events are evident in India also.

The onset and its further distribution of monsoon are erratic in recent decades. Extreme weather events such as floods and droughts, heavy rainfall, avalanches, landslides, heat and cold waves, cyclonic storms, thunderstorms, hailstorms, sandstorms, and cloud bursts are not uncommon and likely to be frequent in ensuing decades under the projected climate change scenario. The impact of drought on Indian food grains production is much more predominant when compared to the effect of flood/heavy rainfall during monsoon since large areas of cultivable land experience drought at a given point in time. Deficit monsoon during 1965, 1966, 1972, 1979, 1984, 1987, 1997, 2002, 2004, 2009, 2012, 2014, and 2015 led to drought and adversely affected Kharif food grains production. Therefore, it is important to understand the impact of climate variability or climate change on crop production as a proactive measure to sustain crop production in the event of climate change and global warming.

The State of Kerala, under the Humid Tropics, is one of the wettest places in the Humid Tropics, where annual rainfall is of the order of 3000 mm, ranging from less than 1000 mm to greater than 5000 mm. About 68 percent of the rainfall is obtained during the southwest monsoon, while 16 percent in the post-monsoon and the rest from summer (14 percent) and winter rainfall (2 percent). A bi-modal rainfall pattern is noticed towards southern districts due to the influence of both southwest and northeast monsoons, while a unified-modal rainfall pattern towards northern districts of Kerala. Coconut productivity is better towards the south despite the dreaded disease of root-wilt when compared to that of northern districts due to fewer dry spells during summer. Floods during monsoon adversely affect paddy production in the State, while prolonged droughts during summer, in the absence of post-monsoon rainfall, adversely affect plantation crops’ production to a considerable extent. The wetlands in Kerala are rich sources of water during summer and act as a sink during the monsoon season. Such wetlands are fast declining in Kerala and converted as garden lands. Decreasing wetlands might be one of the reasons for frequent floods and droughts in Kerala in recent years.

The forest cover of Kerala also declined from 70 percent to 24 percent over a period of one hundred and fifty years due to deforestation and forest fires. The years 1983, 2004, and 2016 experienced prolonged summer droughts in Kerala, and many plantation crops’ production was adversely affected, and the State’s economy was hit badly. The onset of monsoon and monsoon behaviour appear to be erratic in recent years. Frequent failure or break in monsoon across the State leads to low water levels in major reservoirs and adversely affects hydropower generation. There is a significant change in the cropping pattern too over a period of time. Rice and cashew area was declining while the area under rubber and coconut increasing. Vanilla and cocoa were introduced, and in the same fashion, vanilla disappeared, and the area under cocoa declined. An increase in the area under black pepper was noticed across the State and now declining. There was a time that oranges were plenty in Wayanad District and now almost disappeared.

The paddy lands in Wayanad District are mostly converted to areca nut and banana gardens. As a whole, the index of food crops was declining while increasing non-food crops due to various socioeconomic factors. The climate change-related issues over Kerala may be a decline in rainfall, wetlands, land and ocean biodiversity, an increase in temperature and sea level, floods and droughts, landslides, groundwater depletion and saline water intrusion, a decline in forest area, frequent forest fires, unusual rains, and hailstorms. It is believed that almost all the crops are likely to be under threat due to climate change/variability in the ensuing decades under the Humid Tropics. The threat from global warming and climate change could be seen in the form of a decline in cropped area, production and productivity, and quality of grains. Weather and climate play an important role in crop distribution and production. While climate determines the adaptability of a particular crop in a region, weather determines the yield attributes of the crop. Over a period of years, changes have occurred in the natural climate of the earth’s atmospheric system mostly due to human interventions in the form of the emission of large quantities of greenhouse gases (GHGs).

The present level of carbon dioxide concentration in the atmosphere has crossed the 421ppm level. It is now a topic of concern to society. The global mean atmospheric temperature has risen by 1.2°C since 1901. As a result of the dumping of GHGs, the earth’s atmospheric system is getting warmer at an alarming rate, which led to a state called global warming. This will lead to changes in the earth’s climate system. Its impacts are evident in different sectors of society. Extreme weather events are recurring year after year around the globe In Kerala, the occurrence of weather extremes is not uncommon. Unusual summer rains from March 13-23, 2008, devastated paddy production considerably in Alappuzha District and Kole lands of Thrissur District. The summer showers during March 2008 coincided with the paddy harvest season. The harvested paddy and fields under harvest were flooded, causing the paddy to germinate due to wetness, leading to heavy losses. Over one lakh tonnes of paddy were lost during 2007-08 due to floods and unusual summer rains, accounting for a 17% loss in grain yield. It was estimated that the loss due to damaged paddy amounted to Rs.100 crore. Ripened paddy, cashew, and black pepper were damaged.

The unusual summer showers during March-April 2015 caused significant damage to crops and infrastructure. Heavy and untimely summer rainfall due to thunderstorms adversely affected the paddy crops of Kuttanad and Kole lands. The ripened paddy, which fell to the field, could not be harvested due to inundation followed by heavy rainfall, wreaking havoc on hundreds of hectares of paddy fields in these areas. Strong winds devastated banana plants in Kasaragod district during April 2015. Very heavy rainfall on a single day in April 2015 (22nd April) inundated the Capital city of the State and low-lying areas. Monsoon rains during June and July appeared to be less compared to normal rainfall, particularly evident in 2014 and 2015. The monsoon rainfall deficit over Kerala during 2015 was 26 percent, with uneven rainfall distribution. The devastating floods of 2018 and 2019 also wreaked havoc on the state’s agricultural sector. The unusual winter rainfall during 2021 across the state, especially in Idukki district, devastated winter crops (fruits and vegetable crops).

Unusual winter rainfall in December-January across the State was a threat to paddy growers and greatly devastated Kole land paddy. Recurring events of mud slips/landslides across the mid and high ranges of the State during the rainy season pose a threat to the life and property of the inhabitants residing in those areas.Abnormal atmospheric phenomena like heat bursts caused scorching of vegetation across the coastal belt in Kerala during June 2015. A decline in monsoon rainfall with fewer rainy days, floods and droughts, increasing ambient air temperatures (both day maximum and night minimum), a decline in the groundwater table, a decrease in wetland area and surface water resources, loss of biodiversity both on land and water, an increasing number of forest fires and deforestation, increasing events of mud slips/landslides during the rainy season, indiscriminate sand mining from river beds, saltwater intrusion, sunburns, sunstrokes, heatwaves, and increased UV radiation due to ozone depletion are significant climate change/variability-related issues the State is facing.

A significant increase in maximum temperature across the State indicates that Kerala is warming in tune with global warming, moving from wetness to dryness within the Humid Climate. The State of Kerala, located in the Humid Tropics, features a unique system of homestead farming with various crop combinations. Its economy is predominantly based on a plantation economy. Coconut, cashew, cocoa, cardamom, rubber, tea, coffee, black pepper, and areca nut are significant plantation crops in the State, though rice is the main food crop. Coconut is the predominant plantation crop in terms of area and production in the State compared to other plantations. The crops grown in the State must adapt to the climate variability/change observed concerning rainfall and temperature. An increase in daytime temperature and a decline in nighttime temperature are noticed across the high range regions of the State (Idukki and Wayanad). This leads to an increase in the temperature range (the difference between day and night temperatures) across the region, with the rate of temperature increase being relatively high across the high ranges. Crops such as cardamom, tea, coffee, areca nut, and cocoa, grown across the high ranges and sensitive to temperature, will be threatened in the event of rising temperatures, in addition to deforestation due to forest fires. Forest fires are not uncommon across the high ranges during summer.

Trend in rainfall

Trend in rainfall over Kerala shows a decline in monsoon rainfall with an increase in post-monsoon rainfall, though cyclic trends of 40–60 years were noticed in annual and monsoon rainfall. The decline in annual rainfall has been evident for the last 50–60 years. The percentage contribution of rainfall in the monsoon season to the annual rainfall is declining, while it is increasing during the postmonsoon season. However, the increase in post-monsoon rainfall may not compensate for the decrease in monsoon season rainfall. There has been a shift in climate due to changes in thermal and moisture regimes over Kerala, moving from wetness to dryness within the Humid Climate from B4 to B3 over the last 100 to 150 years, possibly due to alarming deforestation and forest fires in the Western Ghats

Temperature projections Temperature projections show that warming in Kerala is real, with a significant increase in temperature since the 1980s in tune with global warming. The rate of temperature increase is high across the Highranges, followed by the lowlands, with a moderate increase along the midlands. This could be attributed to alarming deforestation across the Highranges and the effect of increased sea surface temperature along the Coast. At the current rate of temperature increase, the maximum temperature is likely to increase by around 1.5°C by 2100 A.D., while the minimum temperature may increase by 0.3–0.4°C. The mean surface air temperature is likely to increase by less than 1°C by 2100 A.D. The decade 2011-2020 was the warmest and driest in Kerala, affecting plantation crops’ production considerably. The year 2016 was the warmest, followed by 1987 and 1983. An increase in night temperature during winter in recent years has adversely affected the flowering of fruit crops, particularly mango.

Climate change and coconut

Climate change and its impact on coconut production are evident, with severe summer drought leading to a decline in production under rainfed conditions, though annual coconut production depends on weather factors three-and-a-half years ahead. Good summer showers with shorter dry spells are likely to favourably influence coconut yield in the following year. Drought effects on monthly nut yield start in the seventh, eighth, or ninth month after the drought period, depending on pre-monsoon showers or the onset of monsoon, and continue for twelve months. The decline in monthly nut yield is maximum in the 12th/13th month after the drought period. Most coconut gardens in Kerala show a decline in yield the following year due to drought, explained by the sensitivity of critical crop growth stages to soil moisture stress, which ultimately decides nut yield. A marginal decline in coconut production is also noticed due to long-term climate change, likely affecting nut size and oil content quality due to increased temperatures Agriculture remains the mainstay of Kerala, with its diverse topography, climate, and soil features conducive to a diversified cropping pattern comprising cash crops, food crops, and plantation crops. The sector has seen significant changes, such as a shift from food to non-food crops. Over the last two decades, the share of non-agricultural area in the total geographical area of the State has increased considerably.

Agriculture and the allied sector contributed about 11.28 percent to the total Gross State Value Added (GSVA) in 2021- 22(Q) at current prices. The 13th Five-Year Plan period saw the agriculture sector severely impacted by cyclone Ockhi (2017), the major flood in 2018, and the COVID-19 pandemic. After attaining an annual growth rate of 2.11 percent in 2017-18, it declined to negative growth rates in the following two years. However, growth improved to 4.64 percent in 2021-22 from 0.24 percent in 2020-21, higher than the national growth rate. With limited scope for increasing the cultivation area due to shrinking land availability, increasing crop productivity is essential. This requires reliance on modern agricultural science and practices ensuring higher farm business income and ecological sustainability. Diversification of agriculture is important for income security for farmers, with emphasis on value addition, employment opportunities, improving exports, and strengthening domestic supply chains as thrust areas (Economic Review, 2022).

Vagaries of monsoon, unusual and untimely rainfall, frequent occurrences of droughts and floods, scorching heat during summer, water scarcity for irrigation, and other extreme weather events pose threats to the farming sector in a warming and climate change scenario. Untimely heavy to very heavy rainfall during the crop season in Kole lands of Thrissur during 2021 and 2024 are examples. Occurrences of insect, pest, and diseases are another menace widely noticed across the farming tracts of paddy in Kole and Kuttanad regions. Non-receipt of timely monsoon for the Virippu crop threatens paddy growers in the state, as experienced in recent years in paddy-growing tracts across the State. Traditional farmers of ‘Anchunad’ in Idukki, a village bordering Tamil Nadu, expected to recover from pandemic-inflicted losses, were hit again by adverse untimely and unusual winter rainfall in 2021. Anchunad refers collectively to five villages in Idukki: Kanthalloor, Marayur, Vattavada, Kottakkamboor, and Keezhanthoor.

The unprecedented rains during January 2021 damaged paddy, sugarcane, and vegetable cultivation in these regions. Anchunad, especially Marayur, is considered rain-shadow areas and mostly receive rains from the Northeast monsoon. The traditional belief was shaken when rains hit in the first week of December and the second week of January. Even in the midlands, paddy cultivators suffered due to untimely winter rainfall. This type of unusual and unprecedented weather is likely to occur and reoccur in the State in a warming and climate change scenario. Winter rainfall received during 2024 was similar to 2021 but with a minor impact Kerala, a coastal state in the Humid Tropics, faces frequent weather and climate-related disasters, particularly heavy rainfall during the monsoon season and often scant rainfall from November to May if pre-monsoon showers fail, a situation likely to worsen with climate change. The primary climate change issues in Kerala are a decline in rainfall and a rise in temperature, compounded by year-round UV-B radiation due to ozone depletion, harmful to living organisms. Since 2010, sunburns have been reported in central Kerala (Palghat and Thrissur Districts). Temperature increases vary within the state, being higher in the high ranges and lower along the coast, attributed to deforestation and rising sea surface temperatures. The years 2010 and 2009 were among the warmest in India, with 2016 being the warmest in Kerala.

Kerala experiences summer droughts, contributing to its shift from wetness to dryness within the Humid Climates. The State Action Plan on Climate Change (SAPCC) projects an increase in summer maximum temperatures by 1°C to 1.5°C under RCP 4.5 and 1.5°C to 2°C under RCP 8.5 across all districts, with winter minimum temperatures also expected to rise. Mean annual rainfall is projected to increase under both RCP scenarios, with extremely heavy rainfall events also expected to rise Salinity intrusion along the coast due to sea level rise is alarming. Alappuzha, Palakkad, Wayanad, and Idukki are identified as ‘Climate Change Hot Spots’ in Kerala, with Alappuzha and Palakkad being most vulnerable to climate change. The absence of northeast monsoon and summer showers leads to prolonged drought, significantly affecting plantation crops such as coconut, areca nut, cocoa, cardamom, tea, coffee, and black pepper. Severe summer droughts in years like 1983, 2004, 2014, and 2015 led to massive crop losses and economic downturns. Weather extremes affect perennial crop production not only in the same year but also in subsequent years, depending on the crop’s phenology. Climate factors such as increased temperature, aridity index, and decline in rainfall and moisture index have led to a marginal decline or stagnation in coconut productivity. Climate variability is a major threat to plantation crops’ productivity, with integrated farming or crop mix showing better resilience. The relationship between black pepper and coffee production illustrates that when one crop thrives, the other may suffer under the same climatic conditions.

Recent findings highlight that climate change affects not only crop output but also commodity quality and price, with the recent hike in coconut price partly attributed to the previous year’s summer drought and crop losses in neighbouring states. It’s crucial for government agencies and policymakers to proactively devise shortterm and long-term strategies to mitigate the impacts of weatherrelated disasters through community participation. The National Action Plan on Climate Change (NAPCC) emphasizes ‘Sustainable Agriculture’ as a key area, aiming to make agriculture more resistant to climate change by developing thermally resistant crop varieties capable of withstanding extreme weather, as part of the National Initiative on Climate Resilient Agriculture (NICRA). Kerala requires similar initiatives focused on developing technologies against weather extremes, such as saline/flood resistance and drought resistance/tolerance, rather than just thermal resistance. A State Initiative on Climate Resilient Agriculture (SICRA) should be established to address the needs of plantation crops, horticulture, medicinal plants, and integrated/homestead farming, given the agriculture sector’s dominance in Kerala. This initiative should become operational promptly, considering the significant threat of climate change and variability to plantations and the broader agricultural sector in the Humid Tropics.

The impact of weather on plantation crops is multifaceted, with seasonal rainfall being a key variable. Kerala’s shift from a predominantly wet climate to a drier one, characterized by a decrease in monsoon rainfall and an increase in temperature over the past 60 years, particularly affects plantation crops. The state’s reliance on summer monsoon for 70% of its rainfall, coupled with a prolonged dry season, impacts crop production variably; crops like cashew, black pepper, and coffee benefit from the extended dry season, particularly in the northern mid-highlands, due to their adaptability to rainfed conditions and less harm from prolonged dry spells. In contrast, excessive rainfall can harm crops like coconut and cardamom through waterlogging, while mixed cropping systems offer a way to mitigate adverse weather impacts through diversified income sources. Cashew trees thrive under dry conditions, particularly during the reproductive phase, leading to improved yields. However, prolonged drought beyond the tolerance of specific varieties can negatively impact yield. Temperature extremes above 35°C during the reproductive phase can also affect yield and quality, particularly on the East Coast, whereas more moderate temperatures on the West Coast are beneficial for nut development. Wind speeds and high temperatures in certain periods can limit yields, emphasizing the importance of understanding cashew’s drought tolerance mechanisms.

Cocoa yield is influenced by geographical factors in line with the Hopkins Bioclimatic Law. High temperatures followed by heavy monsoon rains, particularly under waterlogged conditions, are detrimental. However, cocoa’s shade-dependent growth and thermo-sensitivity mean it might withstand gradual temperature increases, though sudden spikes pose a risk. Climate variability, including extreme weather events, poses a greater threat to cocoa than long-term climate changes. The shift in cultivation from tea and cardamom to coffee and black pepper may reflect the advantages of mixed cropping under current climate conditions, offering income stability through diversification. Cardamom yields are heavily dependent on rainfall, with different regions showing varied climate risks. The development of drought and pest-resistant cardamom varieties has helped mitigate some impacts of climate variability. Rubber production is more affected by erratic rainfall patterns than temperature changes, with issues like fungal infections and soil erosion reducing yields.

The use of resistant planting material is key to sustaining rubber production amidst climate variability. Coffee depends heavily on specific rainfall patterns for optimal yield, with Arabica being more weather-sensitive than Robusta. The use of irrigation techniques can offset the absence of natural showers, and the quality of certain specialty coffees is directly linked to monsoon intensity, necessitating research into climate effects on coffee. Black pepper benefits from a long dry season, but summer showers during this period can reduce yield. The relationship between coffee and black pepper yields is complex, often inversely related, highlighting the benefits of mixed cropping in mitigating the effects of dry spells. Temperature increases pose a risk to black pepper, particularly in the context of recent climate trends, warranting further study. Tea production is highly susceptible to sudden weather changes, with recent declines in yield attributed to climate variability, pest attacks, and changes in leaf quality. Increased pest control costs and quality degradation in tea leaves have been noted, with climate variability playing a significant role in pest and disease proliferation. The quality of plantation crops is vital for the export economy but remains under-researched in the context of climate variability and change. The quality of products like Monsoon Malabar Coffee and cashew nuts is influenced by climate factors, including temperature and rainfall patterns, highlighting the need for further investigation to ensure food safety and marketability under changing climate

Weather, climate and rice

In Kerala, rice is a crucial food crop, yet the state’s production falls significantly short of demand, relying on imports from neighbouring states like Punjab, Haryana, Andhra Pradesh, Tamil Nadu, and Karnataka. With a demand for 40 lakh tonnes, Kerala’s rice production hovers around six to seven lakh tonnes, fulfilling merely 15 percent of its annual requirement. Cultivation area has dwindled over time, with rice grown in three seasons: Virippu (May/June-September/October), Mundakan (October/NovemberDecember/January), and Puncha (January/February-April/May). The success of the first crop is monsoon-dependent, the second benefits from post-monsoon rainfall or supplementary irrigation, and Puncha requires irrigation facilities, albeit limited in area. The monsoon’s onset, behaviour, rainfall quantity, and distribution are crucial for the first crop yield.

Excessive and prolonged monsoon rainfall can damage transplanted paddy. Monsoon patterns significantly impact Virippu crop output, grown under rainfed conditions. Breaks in the monsoon, leading to dry spells, are common in Kerala. Continuous rainfall during Virippu reduces evapo transpiration due to lack of sunshine, hindering potential yields. Temperature also plays a vital role, with both high daytime and nighttime temperatures being detrimental to paddy growth. Kerala’s rainfall trends show a decline in annual and southwest monsoon rainfall, with a post-monsoon increase. Temperature increases of 0.99°C (max), 0.33°C (min), and 0.70°C (mean) have been recorded, with night temperature rises particularly impacting rice yields, indicating climate change effects. Agricultural land in India is diminishing, and food grain production is stagnant, mainly due to weather aberrations. Temperature increases could reach 3°C by 2100, impacting food grain production. Severe drought years have historically affected kharif food grain production. Crop simulation models suggest a decline in rice and wheat cultivation areas, threatening total food grain production due to temperature rises and rainfall uncertainties. To address stagnant crop productivity and meet the growing population’s needs without imports, a second green revolution focusing on research and development in agriculture is essential under the climate change scenario

Climate variability and rice production in Kerala

In Kerala, the decline in annual and monsoon rainfall, coupled with temperature increases, affects rainfed rice. Variability in monsoon onset alters planting dates, and drought during reproductive stages can lead to crop failure. Thermal regimes impact rice growth, development, and productivity. With mean annual temperatures rising, there’s a notable impact on thermo-sensitive crops. The year 2016 was Kerala’s warmest, with recent decades showing the driest and warmest trends, exacerbating the impact on rice production. Studies indicate that a 1°C temperature rise reduces paddy yields by 10 percent, highlighting the adverse effects of warmer nights on rice production.

Flood occurrences during the Virippu season threaten rice production. Although only eight flood years have been identified since 1952, many production dips could be attributed to high rainfall, often a localized phenomenon. Documenting flood impacts, especially during Virippu, is essential. As weather extremes are expected to increase, enhancing weather-based forewarning mechanisms at the district level through IMD and KAU collaboration is crucial for minimizing losses.Sea level rise poses a threat to rice production in key areas like Kuttanad, Kole, and Pokkali, where rice is the only viable crop due to unstable water levels and salinity. These productive deltas, crucial for Kerala’s rice bowls, are at risk from rising sea levels and human interventions along the coast. Rice, the staple food for a significant portion of India’s population, sees a clear shift from food to non-food crops in Kerala, with drought during the kharif season impacting national food grain production. Floods and unusual summer showers further jeopardize rice production in Kerala, contributing to food price inflation, underlining the need for comprehensive studies on the climate’s impact on rice production and strategies to mitigate these effects under the climate change scenario.

Weather insurance

Weather insurance is critical for protecting crops and farmers against climate-induced calamities. Farmer suicides in India, often resulting from loan burdens and crop failures due to weather extremes, highlight the urgent need for weather insurance schemes. Compensation should be provided for crop losses caused by weather anomalies like unusual rains or temperature extremes. Ensuring farm-level expected income during weather calamities can help sustain rural livelihoods. Accurate weather forecasting and dissemination of agro-advisory services based on integrated weather forecasts can guide farmers in taking precautionary measures to minimize the harmful effects of weather abnormalities. Strengthening the meteorological network and enhancing proactive measures against weather aberrations are key to reducing crop losses and addressing the challenges posed by weather and climate disasters.