Climate change, signified by global warming, has taken center stage in recent times. An increase in the average temperature of the Earth’s atmosphere, it triggers alterations in the monsoon pattern causing prolonged arid periods and brief, intense downpours. Notably, the year 2022 marked the second highest number of extreme events since 1902, underscoring the urgent need to address climate change.
Impacts of Climate Change on the Indian Monsoon
Climate change significantly impacts the monsoon system by causing low pressure and depression to move south of their position, resulting in flash floods. Monsoon depression, a term used for a low-pressure system affecting the North Indian Ocean and the Bay of Bengal during summers, covers a large spatial area with the diameter of closed isobar reaching up to 1000 km. Consequently, regions like Madhya Pradesh, Gujarat, Rajasthan and parts of Maharashtra experienced excess rainfall in 2022, contrastingly, West Bengal, Jharkhand, and Bihar witnessed a lack of normal rains.
The Role of La Nina and Indian Ocean Dipole (IOD)
Several factors are responsible for these changes – persistence of intense La Nina conditions, abnormal warming of East Indian Ocean, negative IOD, and pre-monsoon heating over the Himalayan region and melting glaciers. IOD is determined by the difference in sea surface temperature between two areas – a western pole in the Arabian Sea and an eastern pole in the eastern part of the Indian Ocean. IOD greatly affects climates of Australia and countries surrounding the Indian Ocean Basin, playing a crucial role in regional rainfall variability.
Implications on Agriculture and Food Security
One significant consequence of these monsoon modifications is on agricultural practices, particularly rice production which comprises more than 50% of total food grain production during kharif season. The regions of Bihar, West Bengal and Uttar Pradesh, constituting a third of India’s total rice production, faced high deficits despite an active monsoon in July and August. These uneven rainfall patterns also impact the grain quality and nutritive value. According to a study titled ‘Climate change, the monsoon, and rice yield in India’, temperatures exceeding 35°C induce heat stress affecting plant physiological processes, causing spikelet sterility, non-viable pollen and reduced grain quality.
Furthermore, these climatic shifts are threatening food security in India. With rainfall becoming more intense but less frequent, hundreds of millions of rice producers and consumers are negatively affected, raising concerns over food security.
Need for Effective Measures
In response to this alarming trend, India needs to invest more resources in enhancing the accuracy of monsoon forecasts to ensure sustainability. As the climate grows warmer, the atmosphere will retain more moisture leading to heavy rainfall, increasing the inter-annual variability of the monsoon in the future. To secure and sustain India’s climate pattern, immediate steps need to be taken not only on the domestic front through the National Action Plan on Climate Change but also internationally through the UN Framework Convention on Climate Change.
Understanding IOD in Context of UPSC Civil Services Examination
A question in the 2017 UPSC Civil Services Preliminary Examination focused on the Indian Ocean Dipole (IOD). It is characterized by a difference in Sea-Surface Temperatures (SST) between the tropical Western Indian Ocean and the tropical Eastern Pacific Ocean. It was emphasized that an IOD phenomenon can either augment or diminish the impact of El Nino on the Indian monsoon. A positive IOD correlates with beneficial rains for India, even in an El Nino year.
The perusal of this topic is crucial, considering the importance of understanding climate change and its implications on monsoons and food security in India, particularly for the candidates preparing for the Civil Services Examination.
