Page 17 - Turkinsurance Digital Magazine

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Temperatures and Heat drops associated with previous La Niña events. As with heat-
waves on land, extreme heat can affect the near-surface layer
of the oceans with a range of consequences for marine life and
The global mean temperature for January to October 2020 was dependent communities. Satellite retrievals of sea-surface tem-
around 1.2°C above the 1850–1900 baseline, used as an approx- perature are used to monitor marine heatwaves, which can be
imation of pre-industrial levels. 2020 is very likely to be one of categorized as moderate, strong, severe or extreme. Much of the
the three warmest years on record globally. Modern temperature ocean experienced at least one 'strong' marine heatwave at some
records began in 1850. The WMO assessment is based on five point in 2020. The Laptev Sea experienced an extreme marine
global temperature datasets. All five of those datasets currently heatwave from June to October. Sea ice extent was unusually
place 2020 as the 2nd warmest for the year to date, following low in the region and adjacent land areas experienced heatwaves
2016 and ahead of 2019. The difference between the warmest during the summer.
three years is small, however, and exact rankings for each data
set could change once data for the entire year are available. The According to International Monetary Fund, the current global
most notable warmth was observed across northern Asia, par- recession caused by the COVID-19 pandemic makes it challeng-
ticularly the Siberian Arctic, where temperatures were more than ing to enact the policies needed for mitigation, but it also pre-
5 °C above average. Siberian heat culminated in late June, when sents opportunities to set the economy on a greener path in order
it reached 38.0 °C at Verkhoyansk on the 20th, provisionally the to boost investment in green and resilient public infrastructure,
highest known temperature anywhere north of the Arctic Circle. thus supporting GDP and employment during the recovery phase.
This fuelled the most active wildfire season in an 18-year long
data record, as estimated in terms of CO2 emissions released
from fires. Since the mid-1980s, the Arctic has warmed at least
twice as fast as the global average, reinforcing a long downward
trend in summer Arctic sea ice extent which has repercussions
on the climate in mid-latitude regions. Arctic sea-ice reached
its annual minimum in September, as the second lowest in the
42-year-old satellite record. Arctic sea ice for July and October
2020 was the lowest on record.

Sea-ice in the Laptev Sea has been exceptionally low through the
spring, summer and autumn, and the Northern Sea Route was
ice-free or close to ice free from July to October 2020. Antarc-
tic ice in 2020 was close to or slightly above the 42-year mean.
Greenland continued to lose ice, losing 152 Gt of ice this year,
despite a slower rate than 2019.

Ocean heat content for 2019 was highest on record in the data-
sets going back to 1960. There is a clear signal for faster heat
uptake in recent decades. More than 90% of the excess energy
accumulating in the climate system as a result of increased con-
centrations of greenhouse gases goes into the ocean. On average,
since early 1993, the altimetry-based global mean rate of sea
level rise amounts to 3.3 ± 0.3 mm/yr. The rate has also in-
creased over that time.

A greater loss of ice mass from the ice sheets is the main cause
of the accelerated rise in the global mean sea level. Global mean
sea-level in 2020 is similar to that in 2019, and consistent with
the long-term trend. Developing La Niña conditions have led to
a recent small drop in global sea level, similar to the temporary