14 | New Scientist | 14 March 2020
“I WAS blown away when I first
saw the skull, it’s so well preserved
and so damn weird,” says Jingmai
O’Connor at the Chinese Academy
of Sciences. “I knew it was so rare.”
This birdlike dinosaur was
discovered in northern Myanmar
and has been analysed by O’Connor
and her colleagues. It is 99 million
years old and the smallest dinosaur
ever found from the Mesozoic era.
CT scans revealed that the
creature, named Oculudentavis
or “eye tooth bird”, had bulging
eyes and sharp teeth (Nature, DOI:
10.1038/s41586-020-2068-4).
Its narrow eye sockets would only
have let in limited light, suggesting
it was most active during the day.
The skull measures just
1.4 centimetres across, indicating
it may have been smaller than any
bird living today, but the jaw shape
suggests it had a powerful bite.
“It was probably smaller than the
bee hummingbird,” says O’Connor. ❚PalaeontologySCIENTISTS have warned that
the world must reduce carbon
emissions to net zero sooner
than 2050, after discovering that
tropical forests are removing less
and less CO2 from the atmosphere.
Climate change models predict
that forests in the Amazon and
equatorial and West Africa will
act as a sink for carbon emissions
well into the second half of this
century. But Simon Lewis at the
University of Leeds, UK, and his
colleagues found that the Amazon
could be a net emitter of carbon
in as little as 15 years. “It’s grim, so
grim. It’s the most worrying paper
I’ve written,” says Lewis.
The researchers looked at
ground surveys of 300,000 treesover 30 years in these regions,
and found that CO2 absorption
in the Amazon has already shrunk
significantly, with equatorial and
West African forests set to follow.
Intact forests across these areas
removed 6 per cent of humanity’s
CO2 emissions in the 2010s, or
around 25 billion tonnes of CO2.
This is down from around 46
billion tonnes, or 17 per cent, in
the 1990s. This change was due to
forests shrinking, the remaining
trees growing less and so absorbing
less CO2, and the huge growth in
carbon emissions from humans.
The researchers used these
observations to model the future
and found that while the Amazon
could become a net source ofcarbon emissions by 2035, the
tipping point for equatorial and
West Africa was far enough in the
future that they didn’t project a
date (Nature, doi.org/ggnd46).
In recent years, there have been
calls to cut global emissions to net
zero by 2050 to avoid temperature
rises of more than 1.5°C. Yet this
deadline is based on models that
assume tropical forests will still be
carbon sinks in the second half of
this century. As this no longer
seems likely, Lewis says we will
“need faster and greater cuts toget to net zero” sooner than 2050.
Stopping deforestation,
which has reached a 10-year high
in Brazil, will also be key, because
disrupted forests are more likely
to dry out and release CO2.
Erika Berengeur at the
University of Oxford says this
analysis provides a good estimate
of tropical forests’ carbon sinks,
but their diminished capability to
absorb CO2 shouldn’t be used as
an excuse to chop them down.
She notes that the study only
focuses on intact forests and that
even though large areas of the
Amazon have been disturbed by
human activities, those parts still
play a vital role in absorbing CO2. ❚Climate changeTropical forests may stop absorbing CO₂
Layal LiverpoolA tiny skull in amber
New dinosaur species identified from 99-million-year-old remains
LIDA XINGNews
2035
The year the Amazon could be
a net source of carbon dioxide Adam Vaughan