Ecology of the past

Frazer Bird on:

Oldfield, F., Steffen, W. 2014. Anthropogenic climate change and the nature of Earth System Science. The Anthropocene Review,1, 70-75.

This paper is a very interesting read for anyone working in the field of palaeoecology. It briefly discusses some of the key criticism of earth systems science research and demonstrates how a good understanding of our past is critical to our future projections.

 “Nature of the Science”

Often Earth System Science is described as being “fuzzy”. It doesn’t always fit the model Popperian approach to science whereby refutable hypothesis are defined and tested. The authors point out however that this is somewhat an unfair criticism. The Earth system is complex, non-linear and often there are no cause-consequence relationships. The scientific method involved is much more complex and often we are trying to understand phenomena that occur over immense timescales. To demonstrate this a little further the authors use the example of freshwater acidification.

“By choosing a variety of field-based case studies with or without key characteristics, each of which was a putative cause of acidification, it proved possible to isolate past variables such as land-use change or catchment afforestation and thereby home in on the only remaining hypothesis not rejected by the evidence, namely the dissemination of industrially generated SO2.”

Rather than testing and refuting or accepting whether industrial generated S02 was causing acidification, cumulative research showed it to be the universal variable across multiple examples. Often when we make inferences about environmental change we have multiple working hypotheses which stand until more and more evidence arises to support one over the others.

 “Toward Projective science”

Projecting the future consequences of climate change is of vital importance for society and critical to policy and mitigation strategies. Climate models are really the only tools at our disposal in trying to understand future scenarios. However models alone cannot provide us with all the answers, the paper demonstrates that the only evidence we ever have is from the past.

“All the evidence we have regarding environmental change comes from the past, whether of the previous few seconds as changes are logged continuously, or of the more remote past revealed through the study of environmental archives.”

If we want to refine our models and have better projections in the future then these tools must have the ability to capture the empirical evidence we have from the past. Future projections are based on data-model comparisons; this is an interactive relationship that is ever refined as each side gains in knowledge and skills.