Ecology is the science of living systems. As a science, it relies on the use of common standards of observation, analysis and collective criticism to build up reliable descriptions and explanations of reality. As biology, it assumes the engineering of organisms through evolutionary responses to design challenges imposed and opportunities offered by the real world. This makes biological thought very practical, and often to do with budgets, investments, costs and benefits that may be expressed and accounted in terms of energy, nutrients and surviving offspring. But being also concerned with systems, ecology focuses on describing the parts, their relationships, the things that connect them, and the properties that result from all the parts, relationships and connections being active within or upon each system.

Since every living system is connected to every other, an ecologist distinguishes them only as a matter of convenience, and has to remain alert to possible influences from abroad at all times. Here, ‘abroad’ means any kind of distance – spatial, but also sensory (that is, what can be detected using our human senses, as constrained by the expectations of our culture and the abilities shaped by our inherent aptitudes and training, and what other organisms can detect using their own senses, which may differ from ours) and instrumental (that is, what can be detected by the instruments we use, as constrained by the expectations of existing knowledge that are designed into the equipment, and which may simply be unable to detect something important). So while proceeding more-or-less within the boundaries of consilient science, this alertness to ‘abroad’ makes ecologists open to the phenomenological diversity that is inherent to anthropology, mythology, psychology and religion, and also to potential connections within and between systems that are invisible to human senses and current instruments.

At the same time, the systems approach requires an ecologist to think in terms of every system being part of a bigger system, in a connected sequence from the molecular to the global level, and with the characteristics of every level both influenced by and influencing every other level, over every imaginable scale of time and space. This is a way of thinking reminiscent of anthropology, since both have the same challenge of reconciling detail and pattern at all scales. Living systems include our own selves, families, communities, farms and dwellings, as well as the atmosphere, oceans, coasts, swamps, grasslands, soils, drylands and forests and all their non-human inhabitants, which make up the living world and every part of it. These are all systems, and climate change is a system-wide phenomenon, so we have no choice but to address it at a system-wide level. In doing so, since every part of the ecological story has to be supported by evidence and reason, the result in ecology is an edifice of systems knowledge that is reliable, vast and inclusive enough to make sense of climate change and help with the challenge of adaptation in all parts of the world and at all scales of human society and the ecosystems that sustain it.

© Julian Caldecott