Turning knowledge of past climate change into action for the future

It’s more helpful to talk about the things we can do, than
the problems we have caused.

Beth Shapiro,
a molecular biologist and author of How To Clone A Mammoth, gave a hopeful
response to an audience question about the recent UN report stating that one
million species are threatened with extinction.

I arrived at the International Union for Quaternary Research (INQUA) 2019
conference, held in Dublin at the end of July, keen to learn exactly that: what
climate scientists can do to mitigate the impact of our rapidly changing
climate. INQUA brings together earth, atmosphere and ocean scientists studying
the Quaternary, a period from 2.6 million years ago to the present day. The
Quaternary has seen repeated and abrupt periods of climate change, making it
the perfect analogue for our rapidly changing future.

In the case of extinctions, if we understand how species
responded to human and environmental pressures in the past, we may be better
equipped to protect them in the present day.

Heikki
Seppä from the University of Finland and colleagues are using the fossil
record to better understand how polar bears adapt to climate change. The Arctic
bears survived the Holocene thermal maximum, between 10,000 and 6,000 years
ago, when temperatures were about 2.5°C warmer than today. Although rising
temperatures and melting sea ice drove them out of Scandinavia, fossil evidence
suggests they probably found a cold refuge around northwest Greenland. This is
an encouraging indicator that polar bears could survive the 1.5°C
warming projected by the IPCC to occur sometime
between 2030 and 2052, if it continues to increase at the current rate.

Protecting animal species means preserving habitat, so it’s
just as important to study the effects of climate change on plants. Charlotte
Clarke from the University of Southampton studies the diversity of plants
during times of abrupt climate change, using Russian lake records. Her results
show that although two thirds of Arctic plant species survived the same warm
period which forced the bears to leave Scandinavia, they too were forced to
migrate, probably moving upslope to colder areas.

If we understand how ecosystems respond to climate change,
we will be better prepared to protect them in the future. But what will future
climate change look like? Again, we can learn a lot by studying the past.

The past is the key to the future

To understand the impact of anthropogenic CO₂
emissions on the climate, we must disentangle the effect of CO₂ from
other factors, such as insolation (radiation from the Sun reaching the Earth’s
surface). This is the mission of Qiuzhen Yin from UC
Louvain, Belgium, who is studying the relative impact of CO₂
on climate during five past warm interglacials. Tim Shaw, from
Nanyang Technological University in Singapore, presented work on the mechanisms driving
past sea level change. And Vachel
Carter from the University of Utah is using charcoal as an analogue for
past fire activity in the Rocky Mountains. By studying the pattern of fire
activity during past warm periods, we can determine which areas are most at
risk in the future.

The 2018 fire season in Colorado was one of the worst on record.

So Quaternary scientists have a lot to tell us about what
our rapidly changing planet might look like in the years to come. But how can
we translate this information into practical action? ‘Science as a human
endeavour necessarily encompasses a moral dimension’, says George Stone from Milwaukee
Area Technical College, USA. Stone’s passionate call to action is part of a
series of talks about how Quaternary climate research can be applied to
societal issues in the 21^st Century.

One thing scientists can do is try to engage with
policymakers. Geoffrey
Boulton of the International Science Council
is hopeful that by partnering with INQUA and setting up collaborations with
Quaternary scientists, it can help them do that. The International Science
Council has a history of helping to integrate science into major global climate
policy such as the Paris
Agreement.

What can we do ourselves as scientists is to portray
scientific results in a way that is visually appealing and easy to understand,
so they are accessible to the public and to policymakers. Oliver Wilson and
colleagues from the University of Reading are a prime example, as they brought
along 3D printed giant pollen grains which they use for outreach and teaching
as part of the 3D
Pollen Project.