New Scientist Australia - 10.08.2019

10 August 2019 | New Scientist | 13

EARTH is a complex machine that

works to support life – and humans

have seized the controls, for better

or worse. That was the message

of a conference held last week to

celebrate the 100th birthday of

James Lovelock, who famously

came up with the Gaia hypothesis.

Lovelock’s idea is that life

on Earth acts to preserve its

own existence, by stabilising

conditions on the planet.

Popularised in the 1970s, it

inspired a generation of scientists

who study Earth’s many systems,

from the climate to forests, and

how they interact as a whole.

Lovelock is famously

independent-minded, and his

idea has attracted more than

its share of eccentrics. This

was evident throughout the

conference, named The Future

of Global Systems Thinking:

Celebrating James Lovelock’s

Centenary and held at the

University of Exeter, UK. At one

point, musician Peter Horton of

Gaia’s Company – a group that

runs workshops and cultural

performances that explore the

Gaia hypothesis’ themes – sang

a bouncy song about how

everything about us is made by

and part of Gaia, from our bones

to our flatulence.

This silliness sat alongside a

serious message. Humans are now

pushing Earth’s systems out of

whack, for instance by releasing

more greenhouse gases than

living organisms can mop up,

and so heating up the planet.

As a result, July may have been

the world’s warmest month in

recorded history.

Scientists at the conference

described the many impacts

humans are having on the planet.

For the first time in geological

history, Gaia has conscious

beings at the controls: a situation

dubbed “Gaia 2.0” by Tim Lenton

at the University of Exeter and

philosopher Bruno Latour of

Sciences Po in Paris, France.

The evidence that our impact on

Gaia is harmful is overwhelming.

Ricarda Winkelmann of the

Potsdam Institute for Climate

Impact Research in Germany

described how the warming of the

planet, caused by our greenhouse

gas emissions, is melting the

great ice sheets of Greenland and

Antarctica. The two sheets contain

enough water to raise the global

sea level by 65 metres.

The Greenland ice sheet in

particular looks very unstable.

Melting the top layer of the ice

means the new top is at a lower

altitude, where temperatures are

warmer. “That means there can

actually be a critical temperature,

associated with a critical elevation,

at which there is no other solution

but for Greenland to become

ice-free,” Winkelmann said.

The enormous volumes of

plastic we produce and (often)

immediately throw away was

highlighted by Tamara Galloway

of the University of Exeter. As

plastic waste in the ocean has

become a widespread concern,

some have argued that this is

“a cosmetic issue” and not a

fundamental threat.

However, Galloway argues that

this is a mistake, because plastics

are made from petrochemicals,

so contribute to climate change.

She highlighted a 2019 report

by the Center for International

Environmental Law, which found

that the production and use of

plastics will emit 0.86 billion

tonnes of carbon dioxide

equivalent this year. “That equates

to 3.8 per cent of total carbon

emissions,” said Galloway.

So what would it take to repair

the damage we have inflicted on

Gaia’s self-regulating systems,

and begin to live sustainably

within them? The solution, many

delegates argued, is to redesign

society (and our culture) so that

it is better suited to Gaia.

To avoid dangerous levels

of global warming, we urgently

need to cut our greenhouse gas

emissions. However, we have

left it so late to act that many

scientists are now also looking

at technologies to artificially

remove and store atmospheric

carbon dioxide (see “Sucking

carbon from air”, page 18).

One such approach, developed

by Tim Flannery of the Australian

Museum in Sydney, is a scheme to

grow seaweed in the open ocean

by pumping nutrient-rich deep

water to the surface. Once grown,

the seaweed could be sunk,

trapping huge amounts of carbon.

At the conference, Flannery cited

a 2012 study which estimated that

covering 9 per cent of the ocean

surface with seaweed would

remove enough carbon dioxide

to restore the atmosphere to a

pre-industrial level.

However, many speakers

raised the spectre of unintended

consequences for such

geoengineering projects.

For example, a huge increase in

seaweed could deprive marine

animals of oxygen. The fact that

such ideas are being considered at

all “shows how desperate people

are getting”, Lenton told me. ❚

More Gaia hypothesis online

Interview: James Lovelock at 100

newscientist.com/lovelock

The Gaia hypothesis says

that life on Earth acts to

preserve its existence

NASA

3.8%

Proportion of our carbon

emissions related to plastics

Conference James Lovelock Centenary

Humans at the helm of Gaia

For the first time in history, Earth’s ecosystems are being shifted by

a conscious species. Will they thrive or fall, asks Michael Marshall