Unleashing Life's Symphony on Earth
Proposals to tackle climate change through physical or chemical engineering of our planet (geoengineering) have major drawbacks, and nature-based solutions such as planting trees face challenges with scalability and effectiveness or exacerbate other problems such as food production.
The unmatched progress in biotech opens up new opportunities to understand the biological controls on our Earth system, as well as new solutions for not just climate change, but other pressing planetary pressure points such as biodiversity. Most importantly, these solutions could be scalable and more targeted.
Terraforming - the act of transforming a degraded or dead landscape into one sustaining life - can be applied to areas of Earth that have come under pressure from climate change.
I have started working on understanding microbes in the environment, and the potential to use nature-based solutions assisted with science and technology to delay the collapse of vital Earth and human systems, and create new well-being and prosperity for people.
Mountains as a source of carbon dioxide
We used to think that mountains absorb carbon dioxide, but our ongoing research is showing that they may be emitting significant amounts of carbon dioxide, contributing to global warming.
It is the recycling of carbon locked in ancient rocks through erosion that releases this carbon dioxide. Mountains as a source of carbon dioxide are a new contributor that we need to account for in our climate models.
The ROC-CO₂ project (Carbon dioxide (CO₂) emissions by Rock-derived Organic Carbon oxidation) aims to quantify the rates and controls on the CO₂ release by erosion and chemical weathering of organic carbon in sedimentary rocks, which is a major component of the geological carbon cycle (see http://roc-co2.weebly.com/ for further information).
As a postdoc on the project, I combine analysis of global topography and models of erosion with geological maps and geochemical datasets. Together with a new geochemical database (Re proxies), I aim to provide a number on how much carbon dioxide is released into the atmosphere from mountains globally.
The role of polar regions in global carbon cycles
While we now know that polar regions are capable of impacting carbon cycles on global scales, up to now we've had very limited constraints on how much carbon they store and cycle. I am part of an international group of scientists led by Professor Jemma Wadham, where we assess for the first time the carbon stored and exchanged from ice to ocean and with the atmosphere across both poles.
Our polar assessment is part of a global effort to constrain the modern carbon cycle, which will help improve our understanding of future climate trajectories and to identify the main targets for solutions.
RECCAP (REgional Carbon Cycle Assessment and Processes) is now in phase 2 (RECCAP-2), coordinated by the Global Carbon Project, and collects and synthesises regional data for 14 large regions of the globe. Read more about RECCAP-2 here.
The evolution of a mountain landscape
During my PhD I worked on the landscape evolution of the Moroccan High Atlas Mountains driven by rivers carving rock. In this mountain belt, the strength of rock types, their organisation in the belt, and the climatic history of the area have dominated this evolution. In particular, I have used river terraces and dating techniques to understand river response to climatically forced erosion and rock resistance in a mountain belt that has largely been tectonically inactive in its recent geological history.
Geological and archaeological material can be dated over a timespan of years to millions of years using the optically stimulated luminescence (OSL) technique. The technique is well established and is used in over 400 laboratories around the world.
I have worked with the Nordic Centre for Luminescence Research (NCLR) at DTU Risø, developer and manufacturer of OSL instruments, to apply innovative techniques and protocols to date fluvial sediments often found in mountainous settings. I also apply rock exposure dating using new techniques pioneered at this laboratory.
This project has so far been awarded five awards and grants to support extending work. Supporters are the Quaternary Research Association, the British Society for Geomorphology, the International Association for Sedimentologists and the Geological Remote Sensing Group.
The project, Quantifying landscape response to tectonics and climate using river terraces in the Atlas Mountains, central Morocco includes updates such as publications on ResearchGate.
My PhD is part of an ongoing effort to understand landscape evolution in the High Atlas Mountains by Dr Martin Stokes, Prof Anne Mather and Dr Sarah Boulton:
Zondervan J.R., Stokes M., Boulton S.J., Telfer M.W., Mather A.E. Rock strength and structural controls on fluvial erodibility: implications for drainage divide mobility in a collisional mountain belt. Earth and Planetary Science Letters, 2020. [link]
Zondervan JR. Lithological and climatic controls on fluvial landscape evolution of a post-orogenic dryland mountain belt. PhD Thesis, University of Plymouth, 2021. [link]
Zondervan J.R., Stokes M., Mather A.E., Telfer M.W., Boulton S.J., Buylaert J.P., Jain M., Murray A.S., Belfoul A. Constraining a punctuated river incision model for Quaternary strath terrace formation. Geomorphology, 2022. [link]
Reading a history of tectonic movement in the landscape
We know that landscapes record the movement along large fractures in the crust, called faults. However, our ability to reconstruct the history and risk of earthquakes from satellite data is limited it is challenging to reconstruct the speed with which such histories progress through landscapes.
I quantified the control of rock strength on the speed at which landscapes respond to active faulting. This allows us to calibrate numerical models aimed at decoding tectonic activity and earthquake risk from topography.
I worked with Dr. Alex Whittaker, Dr. Rebecca Bell, Stephen Watkins and Sam Brooke at Imperial on this MSci project Investigating landscape response to active faulting, Southern Gulf of Corinth, Central Greece.
This dissertation was awarded the BSRG Award for Undergraduate Sedimentology.
Zondervan J.R., Whittaker A.C., Bell R.E., Watkins S.E., Brooke S.A.S., Hann M.G. New constraints on bedrock erodibility and landscape response times upstream of an active fault. Geomorphology, 2020. [link]
The Andes in the deep human past
The tropical Andes is one of the most challenging places to access and discover archaeological sites. Consequently, much is still to be learned about how people distributed themselves across the landscape. I contribute to ongoing work that attempts to build models of human presence in the Andes and its impact on its ecology.
Recently, we found that almost 25% of forest inventory plots between 2.3 and 2.5 km elevation could have been significantly impacted by past human presence. This has implications for how ecologists understand what is natural in the tropical forest.
Sales R.K., McMichael C.N., Flantua S.G., Hagemans K., Zondervan J.R., González-Arango C., Church W.B. and Bush M.B. Potential distributions of pre-Columbian people in Tropical Andean landscapes. Philosophical Transactions of the Royal Society B, 2022. [link]
Ancient pollen of Lake George tell us about past environments
I've also done a project with Dr. Janelle Stevenson and Professor Brad Pillans at the Australian National University (ANU) on the ancient pollen of Lake George, which hosts the longest record of the past environment in Australia.
Feel free to check my report Palynology of Lake George -A review of palynology, Lake George and regional & global Quaternary comparisons and the start of palynological analysis of a new Lake George core.
Fossil corals as indicators of high sea-levels in the past
I'm still waiting for some paleoreef samples to be dated at the Australian National University, as I collected these on an undergraduate project with Dr Bradley Opdyke. This research, Preserved fossil coral heads as indicators of Holocene high sea level on One Tree Island goes into sea level records and isostatic adjustment models.