New Scientist - USA (2022-01-29)

12 | New Scientist | 29 January 2022

Climate change

Earth’s hot streak continued in 2021

THE past seven years were the

warmest on record as climate

change continued apace, despite

the cooling effect of the La Niña

weather pattern in 2021, the

United Nations has found.

The UN’s World Meteorological

Organization (WMO) analysed the

six main global temperature data

sets, which revealed that last year

was the seventh hottest to date, at

1.11°C above pre-industrial levels.

The findings will be published in

April in the WMO’s final report

on the State of the Climate in 2021.

“The continued onslaught

of record years, including the

seven warmest having occurred

since 2015, is precisely what we

expect to see due to human-

caused planetary warming,” says

Michael Mann at Pennsylvania

State University.

Governments at the COP

climate summit in November

reaffirmed their commitment to

trying to hold temperature rises

to 1.5°C and well below 2°C at

worst. But emissions reductions

pledges currently have the world

on course for 2.4°C or more.

2021 is the seventh year in a row

where temperatures have been

more than 1°C above pre-industrial

levels. While it was only the

seventh warmest year on average

globally, 2021 saw climate

scientists shocked by several

temperature records broken by

much larger margins than usual

in some places, such as Lytton,

Canada, which reached a record

temperature of 49.6°C. Previous

research showed this event would

have been “virtually impossible”

without climate change.

“Climate change impacts and

weather-related hazards had life-

changing and devastating impacts

on communities on every single

continent,” said Petteri Taalas

at the WMO in a statement.

Although last year didn’t set a

record for surface air temperatures,

2021 was another record-breaking

year for heat content in the upper

levels of the oceans, which are

absorbing much of the carbon

dioxide emitted by humans and

the heat that this gas traps.

The cooling effect of the La Niña

weather phenomenon – which

brings changes in surface ocean

temperatures that affect climate

patterns – is expected to give way

later this year to its opposite,

El Niño, which was responsible

for 2016 being the hottest year

on record. The UK Met Office,

which holds one of the six data

sets examined by the WMO,

forecasts that 2022 will be 1.09°C

above pre-industrial levels.  ❚

Adam Vaughan

THIS rose-shaped coral has been

found off the coast of Tahiti in the

Pacific Ocean, at depths of between

35 and 70 metres. It forms part

of a reef that stretches for more

than 3 kilometres and measures

70 metres across at its widest.

Laetitia Hédouin at France’s

National Centre for Scientific

Research and her colleagues carried

out a diving expedition off the

peninsula of Tahiti, where they

discovered the reef. It may be

one of the largest at such depths.

“It looks like a giant rose

garden going as far as the eye

can see,” says Julian Barbière at

UNESCO’s Intergovernmental

Oceanographic Commission.

One of the most remarkable

things about this reef is its

pristine condition. “It’s a very

healthy reef, like a dream come

true,” says Hédouin. “In the

middle of the biodiversity crisis,

this is very good news.” ❚

Marine biology

Chen Ly

Pristine coral reef found

Spectacular coral reef discovered deep beneath the sea off Tahiti

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News

1.11 ̊C

Degrees above pre-industrial

temperatures in 2021

New Scientist Video

See video footage of the Tahiti reef and much more online

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