A life of global impact on environmental science

Professor Robert Scholes works in systems ecology at the University of the Witwatersrand

Professor Robert Scholes works in systems ecology at the University of the Witwatersrand

Professor Robert Scholes is one of the top 1% of environmental scientists in the world. He is recognised globally as a leading researcher within environmental science, systems ecology, savannah ecology and global change. His A-rating by the National Research Foundation provides a starting point in understanding the immense global impact that Scholes has had. 

Systems ecology, the approach that underpins the majority of Scholes’ work, takes a holistic approach to the study of ecological systems. Most ecologists study individual organisms in relation to the environment, whereas systems ecology addresses large-scale environmental problems and relates them to human needs. 

Unravelling savannah ecosystems

The professor’s doctoral and post-doctoral work looked at tree-grass interactions in savannahs; it was followed by a book that integrated two decades of savannah research, co-written with Brian Walker. It is still considered a foundational text in savannah ecology.

Savannahs, which dominate Africa, are one of the world’s biggest and most important ecosystems. “However, they have posed a problem for ecologists — while trees and grass displace each other in most ecosystems, why do they coexist in savannahs?” says Scholes. 

In 1997, Scholes and Steve Archer wrote the seminal review on this issue, which proposed a hybrid equilibrium and disturbance theory. Further to that, Scholes’ novel research on the influence of nutrients revealed nutrients to be as important as water in determining savannah function.

As part of his work on savannahs, in 1996 Scholes conducted the first elevated carbon dioxide experiment in Africa. Carbon dioxide concentration was artificially boosted to the levels it may reach later this century. 

In 2000, he established the first eddy covariance tower in savannahs. “It measures the ‘breathing in’ of carbon dioxide by the Earth’s surface during the day and the ‘breathing out’ at night,” explains Scholes. The research around this work has revealed the finer details of savannah ecosystems.

Scholes’ work on savannah dynamics has significantly influenced the management of ecosystems in South Africa (including national parks), with particular respect to bush encroachment, bush clearing and fire management. 

Addressing global change

Scholes was one of the first scientists in Africa to address the issue of global change, starting in 1990. Since then he has published extensively in this field, is considered a leading expert, and has had a key role in drafting national policies, communications and research plans in relation to climate change. 

His expertise is also acknowledged globally concerning the impacts of the terrestrial carbon cycle, biodiversity change and impacts on ecosystem services.

“Global change can be thought of as a symptom of disturbance to the carbon metabolism of the world, resulting from massive injections of carbon dioxide from the burning of fossil fuels,” says Scholes. Land ecosystems take up about a quarter of this excess carbon dioxide and oceans take up another quarter, both playing a critical role in controlling climate change. But the question remains — how long can they continue to do so, and at what cost to their normal function?

Scholes co-led the highly influential study of the generation of soot and gases by fires in southern Africa (SAFARI 2000). As a result, he received the NASA group achievement award. He also conducted the first inventories of greenhouse gas emissions from South Africa and Africa. 

Scientific assessments for effective environmental decision-making 

Among other work for the organisation, Scholes has been a lead author and convening lead author on numerous assessments by the Intergovernmental Panel on Climate Change (IPCC). The IPCC is an international body for the assessment of climate change. It was established in 1988 to provide the world, especially decision-makers, with a clear scientific view on the current state of knowledge in climate change, as well as the potential environmental and socioeconomic impacts.

Following on from his experience in assessment processes with the IPCC, in 2004 Scholes co-chaired the working group on State and Conditions in the groundbreaking Millennium Ecosystem Assessment (MA). 

“The MA did for the rest of the global environmental issues — such as biodiversity loss, overfishing the oceans and desertification — what the IPCC does for climate change,” says Scholes. This has led to a permanent assessment body. The study shows that people’s wellbeing depends on functioning ecosystems. This changed mind-sets worldwide.

Further to this, Scholes’ research with student Reinette Biggs provided a new measure called the Biodiversity Intactness Index. This has been adopted as one of the metrics used globally. 

“It monitors biodiversity change and the research showed that measuring biodiversity loss, which had previously been thought to be impossibly complicated, could be made simple in a rigorous way,” says Scholes. 

Scholes’s work has helped position natural capital globally. He says that natural capital shows that the economic benefits which people derive from ecosystems amounts to trillions of dollars worldwide, arguably equal to or greater than the financial capital usually considered as a metric of wellbeing. The concept allows for better informed decision-making — for example that development pathways, which disproportionately impair natural capital, are ill-advised and unsustainable.

The advantage of this methodology is that ecosystem services can now compete when economic decisions are made.

Earth observing systems

Scholes has worked for two decades on the design and implementation of Earth observing systems, which monitor the health of the planet. He was chair of the Global Terrestrial Observing System and served on the Global Climate Observing System. He was one of four scientists worldwide appointed to draft the implementation plan for the Global Earth Observation System of Systems (GEOSS) in 2004. 

He is part of the team drafting the implementation plan for the second decade of the Group on Earth Observation (GEO).

Considered a “system of systems” and one of the early applications of Big Data, the aim of GEOSS is to link Earth observation resources worldwide across nine societal benefit areas (such as biodiversity). The intention is to make the data available for informed decision-making. 

As part of the work done with GEOSS, Scholes founded and, until recently, chaired the GEO Biodiversity Observation Network. He wrote the plan for the South African Earth Observation System, served on the founding steering committee of the South African Environmental Observation Network, and was on the inaugural board of the South African Space Agency.

Beyond the work mentioned above, Scholes is or has been a member of the steering committee of several International Council of Scientific Unions research programmes. He is also a fellow of the Council for Scientific and Industrial Research (CSIR), fellow of the Royal Society of South Africa, member of the South African Academy, and a foreign associate of the US National Academy of Sciences.

Having left his previous position as a CSIR research group leader at the end of 2014, Scholes is currently a distinguished professor of systems ecology at the University of the Witwatersrand. He says he intends to spend the last decade of his formal working career dedicating more time to training the next generation of systems ecologists. 

Scholes is also currently working on food security in relation to global change, as well as the problem of detecting, understanding, avoiding and fixing land degradation worldwide.

With the upcoming United Nations Climate Change Conference, Scholes says that it is now “crunch time” and that substantial action needs to be taken. “If this is not done, it will be hard to avoid substantial warming,” he notes.