Climate scientists say India and its neighbors will likely experience more heatwaves and droughts, more rain, and stronger cyclones in the coming decades, according to a report released on Monday by the Intergovernmental Panel on Climate Change (IPCC). Scientists have finalized the Sixth Assessment Report (AR6), titled ‘Climate Change 2021: The Physical Science Basis’, in collaboration with 195 governments. It states that heat waves and humid heat stress will be more intense during the 21st century. During this century, both annual and summer monsoon precipitation will increase, as will interannual variability, it said.
According to the report, ‘the observed mean surface temperature increase for the Indian subcontinent clearly exceeded the range of internal variability from 1850-1900’. The report noted that heat extremes have increased while cold extremes have decreased, and those trends will continue in the coming decades. The report said heavy precipitation will also increase over much of Asia.
Due to the increase of aerosols and particulate matter due to human activity, the monsoon in South and Southeast Asia has weakened in the second half of the 20th century. The dry-north and wet-south patterns of East Asian summer monsoon precipitation result from a combination of greenhouse gases and aerosols. As well as this, it stated that South and Southeast Asian monsoon and East Asian summer monsoon precipitation will be dominated by internal variability in the short term and that precipitation will increase in the long term. Droughts are also expected to increase in the subcontinent, according to the report.
As Friederike Otto, Associate Director of the Environment Change Institute at Oxford and one of the report’s authors, noted, ‘The key finding of the report is that climate change is a fact, global warming is a fact, and that human influence has resulted in the warming. We have seen rapid changes across the globe, with heatwaves, heavy rainfall events, droughts and a mix of hot, dry and windy conditions that create preconditions for forest fires. Across the globe, we see this phenomenon. Some of these changes cannot be reversed. Even if we limit temperature rise to 1.5 degrees Celsius from pre-industrial levels, extreme weather events will continue to occur.
Dr. Otto explained that some changes can no longer be reversed, such as rising sea levels and melting glaciers. In India, heatwaves are marked by other emissions, such as aerosols. A second author of the report, Dr. Swapna Panickal of the IITM, said that India will see an intensified water cycle that will impact rain patterns as well as increased monsoon precipitation. ‘As a result of warming sea temperatures in the Indian Ocean, other regions may feel the effect of the changes. We will see an increase in heat waves if there is a decrease in aerosols. Southwest Monsoons have declined in recent decades due to an increase in aerosols, but when they subside, we will see heavy monsoon rains,’ she said.
As a result, the global mean sea level in the Indian Ocean is rising by 3.7 meters per year, adding that extreme sea-level events that previously occurred every 100 years will now happen nearly every year. It was found in the report that the relative sea level in the Indian Ocean, around Asia, has increased faster than the global average, with coastal area loss and shoreline retreat. The regional mean sea level will continue to rise, it said. Climate change will intensify across regions, according to the report. It stated that 1.5°C of global warming would result in more heatwaves, longer warm seasons and shorter cold seasons. Global warming of 2°C would frequently cause heat extremes to reach critical thresholds for agriculture and health.
According to the report, climate change intensifies the water cycle, resulting in more intense rainfall and flooding and more intense droughts in many regions. Rainfall patterns are also affected. Precipitation is predicted to increase in high latitudes, while it will decrease in large parts of the subtropics, according to the report. Moreover, it predicted that sea levels will continue to rise throughout the 21st century, resulting in more frequent and severe coastal flooding in low-lying areas and coastal erosion. Some aspects of climate change may be amplified in cities, such as heat (since cities are generally warmer than their surroundings), flooding from heavy precipitation events and sea-level rise.
‘Because India is among the most climate-vulnerable countries, even distant climate changes can have consequences for monsoons and intensity of extreme weather, observes Dr. Arunabha Ghosh, CEO, Council on Energy, Environment and Water (CEEW). ‘Building climate-resilient physical and digital infrastructure along with inculcating social and behavioral changes in citizens and communities should be our focus. In addition, it should nudge the international community to fund a Global Resilience Reserve Fund to help lower the peak of climate risks for the most vulnerable countries and create an insurance cushion against severe climate shocks’, he added.