Sea level rise: UN report spells doom

Sea level rise: UN report spells doom

In the back drop of the unique global strike demanding more positive action on climate change–possibly the first of its kind in recent years, encouraging comments by Prime Minister Modi at the UN Climate Action Summit in New York have turned the spotlight on not just national contributions pledged under the Paris Agreement of the UN Framework Convention on Climate Change (UNFCCC), but also the possibility of India declaring enhanced ambition on cutting greenhouse gas emissions under the pact next year.

Several aspects place the country in an unenviable position of having to reconcile conflicting imperatives: along with a declared programme of scaling up electricity from renewable sources to 175 GW by 2022 and even to 450 GW later, there is a parallel emphasis on expanding coal-based generation to meet peaks of demand that cannot be met by solar and wind power.

The irony of Modi telling the international community in Houston that his government had opened up coal mining to 100% foreign direct investment was not lost on climate activists campaigning for a ban on new coal plants and divesting of shares in coal companies. No less challenging is a substantial transition to electric mobility, beginning with commercial and public transport, although it would have multiple benefits, not the least of which is cleaner air and reduced expenditure on oil imports.

But this optimism of Modi was possibly lost in the Intergovernmental Panel on Climate Change (IPCC) special report that underlined the dire changes taking place in oceans, glaciers and ice-deposits due to increased temperatures, further acidification, marine heat waves, more frequent extreme El Niño and La Niña events.

“Over the 21st century, the ocean is projected to transition to unprecedented conditions with increased temperatures, further ocean acidification, marine heat waves and more frequent extreme El Niño and La Niña events,” according to a summary of the report made available to policy makers. The ‘Special Report on the Ocean and Cryosphere in a Changing Climate’ updated scientific literature available since 2015, when the IPCC released its comprehensive 5thAssessment Report, and summarises the disastrous impacts of warming based on current projections of global greenhouse gas emissions.

“It is virtually certain that the global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system (high confidence). Since 1993, the rate of ocean warming has more than doubled. Marine heat waves have very likely doubled in frequency since 1982 and are increasing in intensity,” the report noted. The Southern Ocean accounted for 35 to 43% of the total heat gain in the upper 2,000 m global ocean between 1970 and 2017, and its share increased something around 45 and 62% between 2005 and 2017.

The 1.5°C report was a key input used in negotiations at Katowice, Poland last year for countries to commit themselves to capping global temperature rise to 1.5°C by the end of the century. “A major impact is in the Hindu Kush Himalayan Regions,” observed Dr Anjali Prakash, a researcher at The Energy Resources Institute (TERI) School of Advanced Studies, and among those involved with the report, adding, “Floods will become more frequent and severe in the mountainous and downstream areas of the Indus, Ganges and Brahmaputra river basins, because of an increase in extreme precipitation events… the severity of flood events is expected to more than double towards the end of the century.”

In fact, flooding has already become a severe problem for the country and even this year, the rains came late and extensive floods took place. The erratic change in climate behaviour has been continuing for quite some time and there are predictions of this aggravating in the not-too-distant future not just in India but in many other countries in Asia. Even this year, in our country over 1900 people lost their lives and around 50 were reported missing in rain and floods, which affected over 25 lakh in 22 States, according to Union home ministry officials.

The special report has also echoed that four Indian cities — Kolkata, Mumbai, Chennai and Surat — are projected to be affected by a one metre sea level rise by 2100 while several others are expected to face a severe water crisis. These four cities are among 45 such coastal port cities where even an increase of sea level by 50 cm will lead to flooding and affect a total of 15 crore people. Meanwhile, as per studies of Hyderabad based National Centre for Ocean Information Services, the government had informed the Lok Sabha way back on 21 December last that Mumbai and other west coast stretches such as Khambar and Kutch in Gujarat, parts of Konkan and South Kerala were “most vulnerable” to sea level rise

Clearly, threats posed by sea level rise have direct implications for India’s food security of hundreds of millions as its dependent on river water systems that could be adversely impacted by inundation. The studies also projected a sharp increase in population at risk from flooding due to frequent severe weather events.

Further, water demand has been rising sharply with every passing year and hydrologists have predicted that by the end-century, billions are likely to be gripped by water crisis with population explosion that will drive up demand for food and energy and the impact of climate change. According to the UN World Water Development Report, demand for water is likely to increase by 55%, though by current estimates, already over 800 million, if not more, do not have access to safe, reliable water. .

The deltas of Ganga, Krishna, Godavari, Cauvery and Mahanadi in the east coast may be threatened along with irrigated land and a number of urban and other settlements, according to the study. Due to the projected rise, there is also a possibility of coastal groundwater turning saline, endangering wetlands and inundation of valuable land and coastal communities.

While many countries are on target to fulfil their emissions, it is believed that if such emissions are sharply reduced and global warming is limited to 20C,, sea level globally would rise by around 30-60 cm by the end of the century. According to the IPCC report, if collective mitigation targets of all countries under the Paris Agreement are achieved, it will still lead to over 30C rise in temperature by 2100, noting that sea level rise was rising more quickly than previously thought, due to accelerating rates of ice melts.

With a section of environmentalists predicting that the situation will turn alarming by the year 2050 even in India with ice loss in glaciers across the Himalayas having doubled over the past 20 years compared with the preceding two decades, scientists of Columbia University in a report a few months back, added fresh evidence on the impact of global warming on glacial melting. The accelerated melting will initially contribute to excess runoff during summers but, the researchers expect that the volume of water will taper off within decades as the glaciers continue to lose mass.

The looming crisis is undoubtedly a matter of grave concern and pessimists and hard core environmentalists suggest that very little can be done, keeping in view present policies and endeavours of national governments. Will there be a change in heart?




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Sea level rise: UN report spells doom