Over the past decades, few concepts have gained such prominence as resilience. There has been an explosion of research and policies to promote resilient systems, but these efforts have often lacked a clear definition of what resilience actually means, let alone how to apply resilience thinking.

Let us try and explain.

Resilience is the capacity of a system, be it an individual, a forest, a city or an economy, to deal with change and continue to develop. The system will experience shocks and disturbances over time, but these also can spur renewal and innovative thinking.

Our resilience research has three major conceptual strands.

Humans and nature are strongly coupled
Resilience starts from an understanding that humans and nature are intricately linked. The behaviour of these systems is strongly coupled to the point that they should be conceived as one social-ecological system. There are complex interdependencies between people and ecosystems. In our globalized society, there are virtually no ecosystems that are not shaped by people and no people live without the need for ecosystems and the services they provide.

The problem is that too many of us seem to have disconnected ourselves from nature and forgotten that our economies and societies are fundamentally integrated with the living planet. Resilience offers a way to create a new understanding of how humans and nature interact, adapt and impact each other amid change. That is why we argue there is a need to reconnect to the biosphere – the air, land and water on Earth in which all life is found.

We are entering the Anthropocene – the Age of Humans
Human development worldwide has seen tremendous acceleration over the past 200 years, particularly since World War II. Many scientists use the term Anthropocene to refer to this period in history where humanity now influences every aspect of the Earth on a scale akin to the great forces of nature.

There is no doubt that the world's societies have been successful in modifying the planet to meet the growing demands of the human population. But the gains achieved by this spectacular re-engineering have come at a cost.

In spite of immense technological development and progress, our economies and societies still fundamentally depend on ecosystems to provide us with a hospitable climate, clean water, food, fibres and numerous other goods and services. It is now widely apparent and increasingly acknowledged that humanity’s use of the biosphere is not sustainable, breaching planetary boundaries.

Social-ecological systems thinking can enable transformations
The fascinating paradox is that the innovative capacity that has put us in the current environmental predicament can also be used to push us out of it.

Resilience thinking is about generating knowledge about how to strengthen the capacity to deal with the stresses caused by environmental change. It is about finding ways to deal with unexpected events and crises and identifying sustainable ways forward.

Thinking in terms of intertwined social-ecological systems essentially strives to find innovative ways to reconnect with the biosphere and adapt to a wide range of complex challenges. We need innovations that can increase human well-being and at the same time enhance nature's capacity to produce ecosystem services.

Resilience thinking embraces learning and diversity. An immense number of sustainability responses to today's challenges are emerging, such as transition towns, agroecological farming and ecosystem-based fisheries management. Such initiatives need to be scaled up in order to have a global impact. Overall, economic and technological responses, such as innovation funds, seed money and other incentives, must become more ecologically literate. Numerous possibilities exist for investing in the sustainable use of ecosystems and their services.

That is the social-ecological innovation that resilience thinking tries to encourage.

Resilience at the global scale

As scientific understanding advances about the complex interactions of Earth’s physical climate and the living biosphere, the more we recognise that we as human beings are affecting the resilience of social-ecological systems at all scales – including the whole planet. Earth system analysis, using global modelling and Earth observation data, has enabled us to understand many of the risks of human-caused changes to large-scale biophysical processes.

One of the most significant attempts to provide scientific guidelines to maintain Earth's stability and resilience is the planetary boundaries framework. First presented in 2009, the framework highlights nine Earth system processes that have played a vital role in enabling human societies to develop and thrive. The interactions of these processes have contributed to the stability of Earth's climate and ecosystems over thousands of years. Planetary boundaries are quantitative assessments of the level of human-caused change that could generate abrupt or irreversible environmental changes in the system as a whole.

An international community of renowned scientists has assessed that most of these boundaries have already been crossed as a result of human activity, and global trends are worsening for most of the processes. Climate change, loss of biosphere integrity, land-system change, freshwater use, altered biogeochemical flows (phosphorus and nitrogen cycles) and the release of novel entities such as chemical pollution are all shifting the Earth away from the relatively stable and predictable state of the Holocene.

Scientists continue to develop Earth resilience approaches that provide better ways to capture the patterns of Earth's complex behaviour in the Anthropocene, mitigate emerging global risks, and develop strategies for responding to unpredictable aspects of change.