Wide scale appreciation of the fact that human activities can influence the conditions on Earth at the global scale came first from a scientific understanding of human caused climate change. However, climate is not the only important process in the Earth's system that is impacted by human activities. Johan Rockstrom from the Stockholm Resilience Centre together with a group of international colleagues published an analysis in 2009 in which they identified nine processes that all, if sufficiently perturbed, have the capacity to alter the condition or state of the Earth's system as a whole, and that all are well documented to be impacted at the global level by human activities. Human interactions with all of these processes are explicitly or implicitly addressed in the Sustainable Development Goals. Those workers then noted that while modern human beings have been on Earth for hundreds of thousands of years, absolutely everything we associate with modern human civilizations, from the development of agriculture to computers, has evolved during the last approximately 12,000 years. A period in which climate has been relatively warm and unusually stable. We know for certain, in other words, that humanity can thrive under current Earth conditions. We do not know for certain that we can do so when the earth is in other conditions. Therefore, those workers argued, it would be unwise for humanity to allow perturbation of these critical earth processes to reach a degree that poses a serious risk that the earth condition could change to a new state. On the basis of the scientific understanding of how these processes contribute to Earth's system state and how they've varied during the Earth's history, Rockstrom et al then suggested for seven of the nine processes a limit or a boundary for human perturbation above which, they argued, the risk of the perturbation leading to a change in the overall conditions on Earth is increased. These boundaries should not be confused with thresholds or tipping points. They're rather more like when you measure blood pressure. When blood pressure is greater than 120 over 80, there's no guarantee of a heart attack, but the risk of a heart attack is increased. Therefore, we strive to keep blood pressure below this value. In the same manner, the planetary boundaries framework presented by Rockstrom et al argues that if human perturbation of these critical Earth system processes is maintained within the planetary boundaries, humanity is in a safe operating space in relation to its impact on critical global processes. Sustainable development with respect to environment requires that the human demand for the earth's resources and services does not exceed their supply. The planetary boundaries framework can essentially be seen as an attempt to quantify the potential supply of critical Earth system services. Thus, assessing the environmental component of sustainability in the implementation of the SDGs would be greatly aided by having a tool along the lines of a planetary boundary framework. The framework was actually introduced with this idea in mind and the original paper included a call to the scientific community at large for input and improvements to the framework. Many scientists responded and in 2015, a second planetary boundaries paper was published. Here it was concluded that human perturbation of four of the nine processes has crossed the planetary boundary and thereby is currently outside of the safe operating space. Again, this doesn't imply that an environmental catastrophe is imminent. In the 1990s, perturbation of the ozone hole was on the wrong side of the boundary. No extreme catastrophe ensued, but due to global cooperation in the form of the Montreal Protocol banning substances damaging to the ozone layer, perturbation was reduced and we're now in the safe operating space for perturbation of the ozone layer. The four processes for which the planetary boundary is deemed to be crossed are: climate, biodiversity, land use or felling of forests and the release of reactive nitrogen and phosphorus to the environment. In a study published by Campbell et al in 2017, it has been documented that agricultural practices on their own are responsible for the crossing of the planetary boundaries for biodiversity, land use and the release of reactive nitrogen and phosphorus. The Campbell et al study argues that the water boundary may also be surpassed and that agriculture causes substantial perturbation also to this boundary. This emphasizes that achieving sustainable development will require substantial change to our food systems and there is a specific SDG devoted to this challenge. Note that in the planetary boundaries, biodiversity is denoted as biosphere integrity. This is because it's not only the numbers of species and how many extinctions are occurring that is important in terms of biodiversity, but also the intactness and the performance of ecosystems. Biosphere integrity is therefore used as a proxy to describe the role of biological processes in the Earth system as a whole. What actually makes this planet unique in the universe is the fact that there is life. At any given time in the Earth's history, its state is determined by the co-evolution of climate and life or biodiversity. The Earth can, for example, thank biological organisms for the oxygen in its atmosphere, the ozone layer that protects organisms living on land from the sun's dangerous ultraviolet radiation and much, much more. The planetary boundary concept therefore identifies climate and biosphere integrity as the two core processes that we need to be concerned about in terms of human perturbation of Earth system processes. Concern about human effects or perturbation on all of the other Earth system processes identified in the planetary boundary framework is ultimately based on concerns for how they're affecting biosphere integrity and or climate. This means that we ought to worry just as much about human impacts on biodiversity or biosphere integrity as we do about climate. Unfortunately, this is not the case although two of the SDGs, numbers 14 and 15, are specifically devoted to biodiversity or biosphere integrity. Furthermore, as in the case of climate change, there is a UN convention dedicated to biodiversity. Also this convention is supported by a scientific panel the Intergovernmental Panel on Biodiversity and Ecosystem Services, IPBES. I spoke to Professor Neil Burgess who is head of science at UNEP WCMC in Cambridge and Professor of Conservation Science at the University of Copenhagen. He works closely with IPBES and I asked him about the status of biodiversity worldwide. Neil, a lot of people are saying that the biodiversity crisis, what humans are doing to the rest of life on earth, is just as important to humanity's future as climate change. We don't talk very much about biodiversity and the challenges for biodiversity, however. And most people don't recognize it as a great challenge. We do sometimes hear though about the fact that we may be either in or entering the sixth great mass extinction of life on Earth. What does that actually mean? And what is the status for biodiversity on Earth these days? Thank you, Catherine. The balance of scientific opinion from the world that I live in, which is biodiversity science community is definitely that we are entering or already in the sixth mass extinction of life on Earth. We know this because the extinction rate of species is being measured by things like, what's called the IUCN Red List, which looks at the status of all kinds of different species across the planet. And that index is telling us the species are heading towards extinction. So there's lots and lots of birds, mammals, amphibians and other groups of animals and plants which we now are becoming more endangered, more likely to become extinct in the near future, unfortunately. And we know that there has been a fair number of extinctions mostly on islands, small Pacific islands in particular in recent decades. The balance of scientific opinion on this is that we're probably about a thousand times faster at the extinction rates than the geological background. So, over the last many million years, there's been old sea extinction happening. But the basic science at the moment suggests that we are a thousand times faster than that. Neil, when we talk about it being the sixth extinction, then it must have happened before and we're still here. So, should we even worry about it? So, in the past, there's other major extinctions the most recent of the last time I suppose was the extinction of the dinosaurs at the end of the Cretaceous maybe 100 hundred or sixty million years ago. So there was a massive extinction of species then. Lots of things disappeared both on land and in the sea. And indeed life on earth did survive. The extinction of the dinosaurs allowed the mammals ultimately resulting in us to be released from not so much pressure from being eaten by dinosaurs and things like that. So, it benefited the mammals that we came to arise. If we cause a huge mass extinction of all other species or most other species on earth, we may well also be a victim of the consequences of that. Which would mean that something else that is able to survive, will probably ultimately inherit the earth and evolve to fill available niches but the chances of us being around to see that happening are all low. And the life support systems that we rely upon, the plants and animals, habitats, marine, terrestrial all those elements of life on Earth that provide us with the means to survive on Earth. If we take that to pieces by making things extinct, then it's very likely that certain elements of that will collapse or will go outside of the safe operating space for humanity and the planetary boundaries language. Meaning that we don't know if we would be able to survive in the future in a world where we've made lots of things extinct. Two of the SDGs, numbers 14 and 15 actually deal directly with biodiversity but biodiversity is also embedded in a lot of the others. Where do you see the greatest challenges right now in terms of achieving SDGs 14 and 15? So, personally, I think the greatest challenges are in the- if you make the assumption that human species' population is going to grow to nine, ten, twelve billion people on earth, that's every person places the demand on habitats or the sea or species to provide food or forests to provide timber. So there's a pressure applied on the planet by every person on Earth. Some parts of the world the richer countries apply pressure than poorer parts of the world, but everyone applies some kind of pressure on the planet. So the real challenge I think is, having some way to balance the needs of the growing human population and the finite resources of the planet in terms of land, soil, water, some of the fundaments that actually allows us to grow food and produce things that we need, whilst at the same time achieving SDGs 14 and 15, which are about life on land and life in the sea. How do we balance the pressures from farming against life on land requirements to prevent extinction, is one of the indicators of that target. And how do we provide food from fish, I suppose, and maintaining a habitat structure and integrity of the oceans, which is more the focus of SDG 14. But all of us are actually buying products that have been produced somewhere else or something that went into those products has come from somewhere else. So it's really hard to trace our interactions with biodiversity at the end of the day. Do we have any tools that can actually tell us as we sit here in Denmark or wherever buying products how biodiversity has been affected in the production of those products? Beginning to link what's called Trade Flows Models. So, for example you might take oil palm that's coming from Malaysia or Indonesia, and the companies that are producing that in those countries, the companies that are transporting that raw product in ships to refineries, and the companies that are putting it into food or into other products in Denmark, in supermarkets, all the way through. So, increasingly, that's a trade tracking system being put in place. And then increasingly people like me and others are working on the impact of that trade. So, for example, in Malaysia or Indonesia, if you know where Danish oil palm is coming from because you can trace it through their supply chain. And you can see where that's causing deforestation or change of habitats in different parts of Malaysia or Indonesia. And if you know what the biodiversity value of the original forest was, compared to the biodiversity value of the old plantation, you can basically calculate what does the actual impact on the ground of an oil palm plantation in Malaysia or Indonesia and trace it all the way down the food supply chain back to a product in a supermarket in Denmark. So, increasingly, yes. This is possible to do. And I know that there's quite a lot of talk I saw it on the news yesterday about Bitcoin and blockchain and these new technological innovations using computer systems. Now, ultimately, those kinds of computer systems can be applied to global trade as well so that you would know where everything is in global trade at any one time. So some of those technology things, which are emerging, I think will also help us in this regard to know exactly what is the impact of eating that bar of chocolate from that supermarket in Denmark. Fantastic that you can actually with the computers and handling big data may actually help us be able to better the link between humanity and the rest of the organisms living on Earth. Thanks very much, Neil. We, humans, are dependent on other living organisms and have been interacting with them ever since we evolved. After all, we're organisms ourselves and organisms interact with one another. Historically, the impacts of humans on other organisms only took place in local space. In other words, in our own immediate vicinities. Globalized markets, especially for food products have removed, however, many of our interactions with other living organisms from our own immediate vicinities. And we are often unaware of the impacts our actions actually are having on biodiversity. We've realized, in recent years, that the combination of all human interactions with other living organisms is changing both the composition and the performance of the biosphere. That is to say the sum of all the living organisms on this planet at the global level. Fortunately, new computer capacity and the ability to deal with big data are now giving us the opportunity to track all of our interactions with life on Earth. Being able to track these interactions will also, hopefully, allow us to minimize the impact of human activities on other living organisms.
