New Scientist - 21.09.2019

26 | New Scientist | 21 September 2019

Editor’s pick

Several approaches to

rescuing the Arctic Ocean

31 August, p 38

From Fred White, Nottingham, UK

Just how big a cynic does it make me

that when I read Rowan Hooper’s

article on refreezing the Arctic, I

couldn’t shake the conviction

that certain politicians who are

supposedly climate change sceptics

may have links to corporations

that can’t wait to get their snouts

in the geoengineering trough?

From Luce Gilmore, Cambridge, UK

Assuming that the ice does mostly

melt, as seems likely, the Arctic

could be the place that comes to

the planet’s rescue. This may have

happened before. During the early

Eocene Epoch, the atmospheric

carbon dioxide concentration

peaked at more than 2000 parts

per million – at present, it is around

400 ppm (and rising).

The Arctic Ocean had only

one narrow channel to the other

oceans. It probably had fresh

water floating over saltwater.

Blooms of Azolla, freshwater

ferns that fix nitrogen, grew here

and lasted 800,000 years, bringing

carbon dioxide concentrations

down to 650 ppm. Dead Azolla

sank to the anoxic depths, where

its carbon still lies locked.

As geoengineering projects go,

closing off the Arctic Ocean is quite

a modest proposal. Of course, we

would have to wait for the Arctic to

warm a little more and for a floating

freshwater cap to form before a

second Azolla event could really

take off. Thereafter, the process

would be self-sustaining, and

self-limiting once the ice returns.

From Jim McHardy, Clydebank,

West Dunbartonshire, UK

The melting of the Greenland ice

sheet could be reduced by slowing

the seaward movement of glaciers.

Moulins, holes that meltwater flows

down, reduce friction between the

base of the ice and the bedrock.

If a moulin is filled to the top,

water pressure at the glacier base

can be roughly equal to the pressure

of the overlying ice. This results in

the glacier almost floating away

on the water at its base.

Bulldozing dams across the

meltwater streams to divert water

around a moulin and so reduce the

flow under the glacier could be

a quick fix. Or we could use large

solar reflective sheets, supported

by balloons, to cover moulins and

refreeze water. Solar-powered

propellers could keep the reflective

sheets in position.

Money can’t buy you

happiness or contentment

31 August, p 30

From Ros Groves,

Watford, Hertfordshire, UK

Apparently, the search for

happiness is now a well-funded

industry. Surely this calls into

question whether spending so

much time, money and, quite

possibly, anxiety in its pursuit

is counter-productive.

Instead, wouldn’t it be better to

question what exactly happiness

is? To me, it is experienced in

response to a joyous event or

achievement. It is fleeting, before

a return to the baseline. Maintain

this state for too long and it will

lose its magic. More superlative

events will be needed to maintain

this level of happiness, inflating

everyday irritations to trauma.

Surely the answer lies in

contentment? A neutral level

of default temperament offers a

greater ability to enjoy genuine

happiness at all levels, to keep

minor annoyances in perspective

and to promote greater strength

in dealing with misfortune.

Maybe grandchildren, not

children, make us happier

24 August, p 12

From Brian Horton, West

Launceston, Tasmania, Australia

Alice Klein reports that having

children makes us happier, but

only when they leave home. This

is consistent with a previous study

(5 September 2015, p 40) showing

that parents over 40 were happier

than younger parents. I suggested

(Letters, 26 September 2015) that it

is grandchildren who make us

happier. The latest study,

concentrating on parents over 50,

supports this, since children

living at home are less likely

to have their own children.

Please find a lower-impact

kind of random curiosity

10 August, p 38

From Sam Edge,

Ringwood, Hampshire, UK

You suggest readers download

a computer program to search

for Mersenne primes in the

background. Yet every week you

report the looming peril of climate

change and the need to change

our behaviour to limit it.

Modern laptops and many

desktop computers throttle back

the processor speed and put their

drives to sleep when idle. This

significantly reduces power

consumption. Installing software

that keeps the processor loaded

and that reads and writes data

will prevent this – all to try to

find mathematical objects for

the sake of curiosity. How much

extra carbon dioxide do you think

would be released if every reader

did as you suggest?

There are less energy-intensive

ways to find rare things. You could

catalogue birds, insects and plants

for scientific surveys, for instance.

There are also distributed software

projects seeking potentially

beneficial things, such as the

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