Global sea levels rose by a factor of two within 10 years: WMO
This was mostly due to the loss of ice mass from glaciers and ice sheets.
The global mean sea level rose by a factor of two within a period of 10 years, the World Meteorological Organisation (WMO) said on Sunday.
On the eve of the World Leaders Summit at the Glasgow climate change conference (COP26), WMO's provisional State of Climate in 2021 report said the mean global sea level rise was 2.1mm per year between 1993 and 2002 and 4.4mm per year between 2013 and 2021.
This was mostly due to the loss of ice mass from glaciers and ice sheets.
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Arctic sea ice was below the 1981-2010 average at its maximum in March.
Sea ice extent then decreased rapidly in June and early July in the Laptev Sea and East Greenland Sea regions.
As a result, the Arctic-wide sea ice extent was a record low in the first half of July, WMO said.
India lost $87 billion last year due to disasters like tropical cyclones, floods and droughts, World Meteorological Organisation's State of the Climate in Asia report had said last week. Sea surface temperatures in and around Asia are increasing more than the global average at three times the rate in the case of the Arabian sea, it underlined.
Climate scientists said a rapid rise in sea level could threaten India's area stretching over 7,500km.
"Due to ice-glacier melting and thermal expansion of water, sea level will rise further by 40cm to 1m by 2100. Current rates of 3.7cm per decade of sea-level rise are equivalent to tens of metres of land taken away by the sea every decade, considering the slope of the coast," warned Roxy Mathew Koll, climate scientist, Indian Institute of Tropical Meteorology, adding, "The threat due to sea level rise is evident when it overlaps with other extreme weather events along the coastline of India."
"We already see a 50% increase in Arabian Sea cyclones and a threefold rise in extreme rains causing floods. This is projected to intensify further into the future," he said.
Oceans recorded extreme warming in 2021. The upper 2,000m depth of the ocean continued to warm in 2019 reaching a new record high but a preliminary analysis based on seven global data sets suggests that 2020 exceeded that record too.
All data sets indicate that ocean warming rates recorded a strong increase in the past two decades.
Much of the ocean experienced at least one strong marine heatwave at some point in 2021 except the eastern equatorial Pacific Ocean (due to La Niña) and much of the Southern Ocean.
The Laptev and Beaufort Sea in the Arctic experienced "severe" and "extreme" marine heatwaves from January to April 2021. Around 90% of the accumulated heat in the earth system is stored in the ocean.
"The provisional WMO State of the Global Climate 2021 report draws from the latest scientific evidence to show how our planet is changing before our eyes. From the ocean depths to mountain tops, from melting glaciers to relentless extreme weather events, ecosystems and communities around the globe are being devastated," said United Nations secretary general António Guterres.
"COP26 must be a turning point for people and planet," he added.
Last seven years on track to be hottest on record.
The past seven years are on track to being the seven warmest on record, according to the report, based on data for the first nine months of 2021.
This year was marginally less warm than previous few years because of temporary cooling due to La Niña but this does not negate or reverse the long-term trend of rising temperatures, WMO cautioned.
The global mean temperature for 2021 (based on data from January to September) was about 1.09°C above the 1850-1900 average.
Currently, the six datasets used by WMO in the analysis place 2021 as the sixth or seventh warmest year on record globally. But the ranking may change at the end of the year.
Extreme heatwaves affected western North America during June and July, with many places breaking station records by 4°C to 6°C and causing hundreds of heat-related deaths.
Lytton, in south-central British Columbia, reached 49.6°C on 29 June, breaking the previous Canadian national record by 4.6°C.
