Climate Change is Turning Indian Monsoon Season Stronger, More Erratic: Study | The Weather Channel – Articles from The Weather Channel | weather.com – The Weather Channel
In 2019, most forecasters agreed that the monsoon season will be much drier than normal and yet, the seasonal rainfall ended up 10% higher than normal. Even in 2020, forecasts suggested a normal monsoon and the rainfall totals remained 9% higher than the seasonal norm. Why is the southwest monsoon in India outperforming expectations in recent years? Scientists may have an answer: Climate Change.
The monsoon season holds the credit to bring a remarkable 80% of the total rainfall in India. For an agrarian economy like India, such bountiful rains are the safety net for millions of farmers. The rainy season—from June to September—rejuvenates the parched lands, restores water sources and provides much-needed relief from sweltering summer. Yet, the increasingly erratic nature of monsoon has remained a cause of concern.
Now, a new study from a team of German scientists projects a grim picture for India as it shows that the monsoon season will turn stronger and more erratic due to climate change.
Sharp increase in monsoon rains
Over the last 20 years, 13 monsoon seasons have witnessed a rainfall deficit. Therefore, a projected increase in rainfall may seem like welcome news, but it is not! Increased rainfall over a shorter period of time usually wreaks havoc across the country’s flood-prone regions. Meanwhile, the increasingly erratic nature of the monsoon can spell doom for the drought-prone regions in central, western and eastern India.
The study projects that even with a degree celsius rise in temperatures, the monsoon rains are expected to increase by at least 5%. The Earth’s average surface temperature has already increased by 1.1°C above the pre-industrial levels. Moreover, scientists have warned that the global temperatures could rise beyond 3°C if countries fail to take timely action.
Such a drastic increase in rainfall can have serious implications on the farming sector, in particular, in terms of lost yield.
The co-author of the study, Julia Pongratz from the Ludwig Maximilian University, Germany, explains: “Crops need water especially in the initial growing period, but too much rainfall during other growing states can harm plants—including rice on which the majority of India’s population is depending for sustenance. This makes the Indian economy and food system highly sensitive to volatile monsoon patterns.”
Apart from damaging the crops and swamping the agriculture fields, extremely wet weather can also impact public health, as monsoon season turns breeding ground for epidemics and vectors.
Shift in rainfall pattern
The behaviour of monsoon is at the whim of global weather forces, which often happen at a far distance way beyond our borders. Besides, even a small deviation in sea-surface temperatures or wind pattern can impact the amount of rainfall India receives during the monsoon months.
The researchers tracked the shift in the rainfall pattern since the 1950s. This is the period—often terms as the ‘Great Acceleration’—when human activities started to induce slow yet visible changes in the global weather pattern. In the 1950s, the formation of aerosol led to the decline of rainfall while in the 1980s, the higher amounts of greenhouse gases started to create a stronger and more erratic rainfall season.
“Hereby we were also able to confirm previous studies but find that global warming is increasing monsoon rainfall in India even more than previously thought. It is dominating monsoon dynamics in the 21st century,” states lead author Anja Katzenberger from the Potsdam Institute for Climate Impact Research, Germany.
The monsoon season brings varying amount of precipitation to the subcontinent every year. This unpredictability, along with global warming, would be a double whammy for the continent in the near future.
The study’s predictions are based on the information derived from 30 state-of-the-art climate models from all around the world.
On a positive note, the India Meteorological Department (IMD) has forecast normal rainfall for this year’s monsoon season. As per the seasonal outlook, the monsoon rainfall across India is likely to be 98% of the Long Period Average (LPA) in 2021, with a model error of ±5%.
The study has been published in the journal Earth System Dynamics and can be accessed here.