Human Traces - Synthesizing human traces in the stratigraphic record

The working group Human Traces aims to place contemporary human impacts within a longer temporal context using a meta-analysis of existing Holocene records.

Human activities in the Paleoanthropocene had regionally asynchronous impacts that manifested differently in various parts of the world. Stratigraphic archives, including lake sediments, peat, coastal and marine deposits, but also archeological sites, ice cores and tree-rings, serve as long-term records of natural variability and human-induced changes to the Earth system, allowing us to assess responses to change on various timescales and to link them with either climatic or anthropogenic drivers.

They also serve as a way of defining targets/reference conditions for ecosystem management and conservation by providing a longer-term perspective for recent global changes in the context of the Anthropocene. Quantifying both natural variability and the slow-evolving, low-intensity anthropogenic perturbations are essential if we are to improve predictions of future environmental dynamics and inform strategies for sustainability.

Phase II

Our main goal is to address the question of how the Anthropocene manifests itself in natural archives in different parts of the world depending on regional aspects of historical, natural and human-induced change.

Even though we focus on the paleolimnological approach, we have included other types of archives and human traces since the beginning. The synthesis currently being conducted for South America involves for instance also archeologists and anthropologists. During phase two, we want to expand our regional syntheses by reaching out to the Chinese community.

This second phase will allow us to significantly develop the research database, starting with published lake lead records.

Planned activities

We had an in-person workshop in Liverpool in September 2023 bringing together the Pb records and establishing the database. This should be functional by 2024, when we will conduct a community survey and hold an online workshop to assess its functionality and decide on the next Human Traces to include.

We aim to hold an in-person workshop in the second half of 2024 to kick off the regional synthesis of Human Traces in Oceania. This meeting will be organized by Dan Penny in Australia. We will also work towards starting our first Summer School in the NH summer of 2024.

In 2024, we will also start a discussion with the other WG interested in the “Society” aspect to propose the production of a Special Issue in the PAGES magazine on this topic.

The workshop could for instance be held at the next OSM, but does not have to be.

In 2025, we will hold a workshop right before/after the OSM in Shanghai dedicated specifically to researchers working with Human Traces in China and Southeast Asia, to set up a Synthesis for this region of the World. 

We will also continue to expand our database by including additional proxies and archives of human traces.

The year 2026 will be used to finalize the various syntheses started and write a perspective of what is a Human Trace and how it evolved in time and space.

We have also discussed the possibility of hosting a meeting on dam reservoirs as tracers of human impacts on the environment that would be held in North America.

Phase I 

Background

The previous iteration of this WG, Aquatic Transitions, was active from 2014-2018. It published about the challenges of separating natural from anthropic drivers of change in lake sediment signals (Mills et al. 2017) and also on documenting the first human impacts on lake ecosystems around the world (Dubois et al. 2018). Human Traces will build on these to move forward.

Aims

Human Traces will address the question of how the Anthropocene manifests itself in natural archives in different parts of the world depending on regional aspects of historical natural and human-induced change. We will first start with the paleolimnological approach, a multidisciplinary science that combines a variety of biological and geochemical information stored in lake sediment archives.

We will assemble a research database, starting with published lake geochemical records and aquatic bioindicators that contains sufficient information to establish temporal trends in nutrient and matter fluxes, building on the efforts of the Aquatic Transitions working group.

Following a research community survey, we will identify parameters considered essential to a flexible community data resource for Human Traces records and establish a data structure and associated tools suitable for flexible and open access to the data. A recurring Summer School will be established to share best practices.

Planned activities

Online meetings will be held on a three-month basis in order to ensure progress in and exchange between the workshops. These online meetings will be used to (1) collect and control the data to populate the database, (2) work on the manuscripts (see expected outputs below), (3) prepare the Summer School.

2021
- Monthly meetings of the Steering Committee to set up the working group and create the research community survey to build the database.
- Community survey and database building (ongoing).
- Second quarter: Workshop to initiate exchanges with the other working groups in the human dimensions of PAGES (LandCover6k, PEOPLE 3000 and DiverseK), centered on the theme: "What is a human impact/trace in a record of broad interest."

2022
- March: Potential meeting of the Steering Committee at the IPA-IAL in Bariloche, Argentina, to prepare for the first workshop.
- May: First in-person Human Traces workshop at the PAGES OSM in Agadir, Morocco. This meeting will also be open to online participants.
- Mid-year: First Summer School.

2023
- July: Second in person Human Traces workshop at the XXI INQUA Congress in Rome, Italy. This meeting will also be open to online participants.
- Mid-year: Second Summer School. The Summer School could also be open to online participation, depending on the global sanitary context. We plan to hold the Summer Schools in three different locations in order to facilitate participation by as many people as possible. Location could be based on the geographical distribution of students and ECR members in the WG.

Training the next generation of scientists in quantitative biogeochemical paleolimnology and other stratigraphic approaches, and fostering an environment where they can take active part in networking and building collaborative science is an important part of this working group's program.

Learn more and participate

This group is open to anyone who is interested, and early-career researchers are encouraged to be involved:

- The Human Traces working group has launched a webinar series which is free to attend. 
- Sign up to the Human Traces mailing list
- Follow the group on Twitter: https://twitter.com/HTraces
- Follow the group on Facebook: https://www.facebook.com/HTraces
- Subscribe to the Human Traces YouTube channel
- Contact the Steering Committee
- Find out more about the group's scientific goals