Kerala, known for its maritime equable climate, has been experiencing a significant rise in temperatures in recent years. A recent climate statement prepared by the Institute for Climate Change Studies, in collaboration with the India Meteorological Department (IMD), stated that 2024 was the warmest year recorded in Kerala since 1901, with the annual mean temperature increasing by 0.99 degree Celsius compared to the long period average.

Out of the nine warmest years recorded prior to 2024, only one falls outside the last decade. While variations exist across states due to geographical factors, Kerala’s warming pattern is consistent with national and global trends. The average southwest monsoon season rainfall during the period 1901-2024 shows decreasing trends in all the districts except in Idukki, where increasing but insignificant trend is seen.

“The temperature rise in Kerala is in line with global trends, with 2024 being confirmed as one of the hottest years on record, as global temperatures crossed 1.55 degrees Celsius, surpassing the Paris Agreement’s 1.5-degree threshold,” Sinan Nizar, junior scientist at the Institute for Climate Studies, told Onmanorama during the News Brake podcast. The World Meteorological Organization (WMO) has confirmed that 2024 was the hottest year on record globally and India's warmest year ever. Data from the India Meteorological Department's climate summary shows that the annual average land surface air temperature was +0.65 degrees Celsius higher than the long-term average (1991-2020) in 2024.

In India, 10 out of the 15 warmest years were observed in the recent fifteen years (2010-2024). The past decade (2015-2024) was also the warmest decade on record, with the decadal averaged annual mean temperature anomaly of 0.31 degree Celsius.

Rising heatwaves and climate extremes
One of the most pressing concerns arising from this warming trend is the increased frequency of heatwaves. Though Kerala, being a coastal state, does not experience the extreme temperatures seen in northern India, high humidity levels can exacerbate heat stress. “Despite not always being marked on heatwave maps, the state may face severe heat-related challenges due to compounded climate extremes,” said Nizar.

The impact of heatwaves could be further intensified when combined with other climatic events. For instance, even a mild drought coupled with a slight heatwave could lead to severe water stress, affecting both agriculture and daily life.

Changing monsoon patterns
Along with rising temperatures, Kerala has been witnessing significant changes in its monsoon patterns, with deficits during the southwest monsoon and surpluses in other seasons. According to the climate report by ICCS, Kerala experienced a rainfall deficit of 13% below its long-period average (1991–2020) during the southwest monsoon season in 2024. However, it recorded an excess of 183% and 39% above its LPA during the winter and summer seasons, respectively.

While total annual rainfall may not fluctuate drastically, its distribution is becoming erratic, with longer dry spells followed by intense bursts of rain. This shift poses a threat to the state’s predominantly agrarian economy.

“A study conducted in the Bharathapuzha river basin, in collaboration with the Centre for Resource Development and Management in Calicut, found that rising temperatures and changing rainfall patterns will likely reduce crop yields in the future. Increased soil erosion from intense rainfall, coupled with changing diurnal temperature variations, is making it difficult for crops to adapt,” Nizar said. Genetically modified crops, diversification, and improved farming practices will be crucial in ensuring food security in the future.

Urban heat island effect
While global greenhouse gas emissions remain the primary driver of climate change, regional factors also contribute to Kerala’s warming. Deforestation and rapid urbanisation are playing a role in trapping heat and altering local climates. The urban heat island effect, caused by concrete structures absorbing and retaining heat, is making cities in Kerala warmer than surrounding rural areas. Dr Nizar stressed the need for sustainable urban planning, including creating more green spaces and strengthening public transport systems to reduce emissions.

Kerala has made notable progress in disaster management, with its State Disaster Management Authority being recognised nationally. However, experts argue that early warning systems need further strengthening, given the state’s unique geographical and climatic challenges. There is also a need for an interdisciplinary approach involving forest officials, environmentalists, and policymakers to develop sustainable solutions to tackle the escalating human-animal conflict in the state.