44 | New Scientist | 5 February 2022
F
ROM the breathtaking Atlas mountains
in Morocco to the expansive deserts
of the US, Christopher Jackson’s work
has taken him to some incredible places.
Incredible and sometimes risky, too: he has
been held at gunpoint and put in prison in
the line of duty. Why does he do it? Just for
the sake of a few old rocks.
Geologists might have a long list of
adventure stories to recite and an enviable
set of stamps in their passports, but Jackson
says that in many people’s eyes, they don’t
have a good reputation. After all, they often
use their knowledge of Earth’s rocks and
tectonic processes to identify rich mineral
seams to dig up and fossil fuels to drill, all
of which is a horror to the environment.
Now, Jackson is seeking to flip the story.
As chair in sustainable geoscience at the
University of Manchester, UK, he says
geologists must play a crucial part in fighting
climate change. That means helping to
create technologies that allow us to live more
sustainably and spreading the word about
our planet’s climate history. Earth’s rocks were
formed at various points in the past, and their
chemistry and structure reflect the conditions
that prevailed at the time. This geological
record can be read to reveal how our planet’s
climate has warmed and cooled over the
aeons – a story that can help us better
understand climate change in our own time.
Jackson spoke to New Scientist about his epic
travels, how geology can help us live with less
environmental impact and the difficult task
of improving diversity in geosciences.Abigail Beall: Your job has taken you to lots
of exciting places. Do you have a favourite?
Christopher Jackson: As a geologist, you
go places that few others ever get to visit
because you’re interested in rare, weird
rocks and those tend to be in far-flung
places. That’s always a tingle.
The Atlas mountains were pretty
spectacular. I went there to study the
way rock salt deforms to generate giant
structures within the Earth’s crust. You
drive across these desert plains for several
hours and you eventually start to wind upin mountains, at really high elevations. You
go from desert to forested areas to then bare
rocks. It’s remote and beautiful country with
beautiful people living there.I imagine it can be dangerous at times.
My colleagues and I have had guns pointed
at us in Egypt. We were arrested there and had
our passports confiscated. In Argentina a few
years ago, we got arrested and put in a prison
in a cell overnight. I’ve had racist abuse in the
US while doing fieldwork at the Colorado-Utah
border. Sometimes, people can be suspicious
of geologists on their land, even though you
have the right permissions to be there.A lot of this work is to understand Earth’s
past climate. Why is that so important?
The trouble is that in some people’s minds, it’s
cold at the North and South Pole and it’s very
hot in the deserts, yet people have managed
to survive in all those places. So what harm
can a few degrees of global warming do?
The information we can gather from
layers of rocks built up in Earth’s surface
over millennia can answer that question.
It tells us how the changing climate impacted
the existence of living creatures on Earth.As selfish beings, that’s what we’re concerned
about, right?
The rock record tells us that abrupt, large
swings in climate, such as we’re presently
seeing, can lead to the dramatic loss of life.
Looking back into the geological record
gives us a baseline to understand what we’re
living through now and what we might live
through in the future.How can rocks tell us about the effects that
past changes to the climate had on life?
The first job is to understand what the climate
was like in the past, and for that we need to
use proxies, signals in ancient rocks that
vary in ways that were affected by things
like temperature or rainfall. We commonly
analyse the chemical composition of very
small marine fossils called foraminifera in the
rocks. Sometimes the composition and texture
of the rocks themselves record climatically
driven events such as sea level rise. The other
thing we do is use the fossil record to look
at extinctions. Then we can compare the
two timelines and see correlations between
changes in temperature, say, and what
happened to Earth’s biodiversity.What sorts of things do we learn
from those timelines?
One interesting point is how things livingJOHANN^ RAG
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MY“ We need to
be aware of
geological
history and how
it could replay
in our time”
Want more from Christopher Jackson?
Hear him speak at New Scientist Live next month
newscientistlive.com