Postgraduate research

A resilience index for Earth-type biospheres

Qualification: now

Department: Geology

Application deadline: 9 June 2023

Start date: 25 September 2023


University of Leicester 3.5 Year Future 50 Studentship within the Institute of Environmental Futures


Professor Mark Williams (Geology)

Professor Sergei Petrovskiy

Project Description:

1. Develop a habitability index for Earth’s biosphere

2. Interrogate models of deep time biotic change

3. Use your analysis to understand current impacts on the biosphere

Planet Earth has been continuously habitable for at least 3.5 billion years. During that immense time the Earth has been subject to considerable environmental perturbation, resulting from both intrinsic and extrinsic forces. These range from the small-scale, such as solar radiation changes from orbital forcing mechanisms, to the very large scale, such as an asteroid strike. The biosphere has shown considerable resilience to perturbation and provides the only quantifiable measure of habitability available to us in the Cosmos. Here we seek to relate the ‘energetics’ of environmental change to the degree of change seen in the biosphere, thereby quantifying its likely response to different degrees of perturbation. 

How might this be quantified? We would focus on a range of key geological events with well-documented records, ranging from smaller-scale episodes of change, such as the Mid Miocene climate optimum (circa 15 million years ago), to much larger environmental perturbations, such as the Great Oxygenation episode (circa 2.4-2.0 billion years ago). Taking these endmembers, one fully reversible, the other irreversible, we would seek to quantify the relative position of a range of more minor to more major biotic events and examine the driving mechanisms of such change. Events of intermediate scale include the Palaeocene-Eocene thermal maximum (55 million years ago), which caused an irreversible change to several components of the biosphere (a minor extinction), and the Permian-Triassic extinction, with the loss of 95% of species diversity. Finally, we would ask the question, do events lie on a continuum from ‘no change’ to ‘wholesale change’, or show diagnostic groupings indicative of a system in various degrees of state shift? We would use this analysis to examine questions of biosphere resilience and establish an index of habitability according to different levels of perturbation. Notably, we would then apply our index to try and understand the likely level of biotic change resulting from current (considerable and human-induced) environmental change in the 21st century.



Future 50 Studentship provides:

  • 3.5 years Stipend at UKRI rates, currently at £17,668 per annum (2023/2024 rates yet to be announced)
  • 3.5 years Tuition Fees at UK rates (£4,712 for 2023/4)

International students must be able to fund the difference between UK and International fees for the duration of their studies. This will amount to £17,138 per year.

Entry requirements

Entry requirements

Applicants are required to hold/or expect to obtain a UK Bachelor Degree 2:1 or better in a relevant subject. 

The University of Leicester English language requirements apply

Informal enquiries

Informal enquiries

Project enquiries to: Professor Mark Williams 

Application enquiries

How to apply

How to apply

To apply, please use the Apply button at the bottom of the page and select September 2023 from the dropdown menu.

With your application, please include:

  • CV
  • Personal statement explaining your interest in the project, your experience and why we should consider you.
  • Degree Certificates and Transcripts of study already completed and if possible transcript to date of study currently being undertaken.
  • Evidence of English language proficiency if applicable.
  • In the reference section please enter the contact details of your two academic referees in the boxes provided or upload letters of reference if already available.
  • In the funding section please specify Future 50 RI EF Williams 
  • In the research proposal section please provide the name of the project supervisors and the project title (a proposal is not required).



Open to UK and International* applicants

*International applicants please refer to the funding section.

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