26 | New Scientist | 7 December 2019
Editor’s pick
Transparency on political
advertisement targeting
16 November, p 24
From Adrian Bowyer,
Foxham, Wiltshire, UK
Annalee Newitz is right that the real
problem with fake and lying political
advertisements isn’t that Facebook
and others promulgate them,
but that they allow them to be
micro-targeted, thereby avoiding
detection by the rest of us, and by
journalists in particular.
If it wanted to, Facebook could
easily avoid this problem, while
maintaining both its micro-
targeting business model and its
decision not to censor political
advertising. For the current system
to work, each advertisement must
have micro-targets specified by the
advertiser. There is no reason to
keep these secret: advertisers being
ashamed of them is no justification.
The micro-target specifications
could be indexed along with the
corresponding advertisements.
The index could be searched to see
the advertisements that had been
targeted at any group of people.
Most of the software needed to do
this is already part of the system.We have a model of global
climate cooperation now
Leader, 23 November
From Austin Woods, London, UK
You ask us to imagine an
international research institution
dedicated to climate change,
bringing together “the best
minds from climate science,
energy technology, economics,
social science and beyond”.
The European Centre for
Medium-Range Weather
Forecasts, based in Reading, UK,
is an international institution
supported by 34 states. It employs
around 360 highly qualified staff
from more than 30 countries.
More than 60 of its professional
staff operate the Copernicus
Climate Change Service of the
EU’s Copernicus Earth observation
programme. Its supercomputerand associated data archive are
among the largest in the world.
Its data assimilation system
and its model of the global
atmosphere, oceans, land and ice
are the world’s most advanced.
With this foundation, an
extension to the international
research institution you envisage
could surely be managed without
too much delay. Can the next UK
government provide the required
global scientific leadership?Keep this genie sealed up
in its squirt bottle please
9 November, p 7
From Michael Phillips,
New York, US
Michael Le Page reports genetic
engineering of plants using a
spray-on mix of carbon dots and
DNA coding for a CRISPR system.
This could be hazardous to
humans. Like many nanoparticles,
carbon dots easily penetrate the
skin, and they are increasingly
used for drug delivery.
A human exposed to that
spray could be at risk of droplets
entering the body through the
skin or nasal mucosa, or inhaled
into the lungs. If carbon dots enterthe systemic circulation, then
bound CRISPR DNA could modify
the genome of any cells it infects.
While this appears to be a
powerful new gene-editing tool in
plants, there is a risk that it might
edit human genes as well. Until we
learn more about it, regulators
ought to keep this genie firmly
sealed up inside its squirt bottle.Tree planting is something
we can do for the climate
10 August, p 18
From Adam Osen,
Harlow, Essex, UK
Your article on ways of removing
carbon dioxide from the
atmosphere was fascinating.
Options included bioenergy,
carbon capture and storage and
sequestration of carbon in the soil.
The only one on your list that
ordinary people can do is to plant
trees. But how effective is this?
An average person in a
developed country releases
about 14 tonnes of CO 2 a year and
the average tree absorbs about
22 kilograms a year. So to be
carbon neutral just by planting
trees, the average person would
need to plant 680 trees a year.There are carbon offset
schemes, but the link between
our money and trees being
planted that wouldn’t otherwise
be planted is tenuous. My family
is planting trees in Portugal at €15
per tree: 680 would cost €10,000.
Possibly we will never plant all of
them, but we count each we plant
as 13 hours of carbon offset, even if
we do nothing else.
That figure of 680 trees is an
underestimate, because as CO 2
levels have risen, the oceans have
been compensating to some
extent by absorbing CO 2. The
oceans will release some of this
when we remove CO 2 from the air,
however we do it.
But we will do other things
as well as planting trees, even as
individuals, which may balance
things out.Can a group of AIs actually
simulate a chaotic world?
5 October, p 38
From Ben Haller,
Ithaca, New York, US
Graham Lawton claims that a
type of simulation called multi-
agent artificial intelligence is
about to upend the world withViews You r le t te r s