The earth’s climate has already reached a tipping point. Glaciers from the Greenland and Antarctic Ice Sheets are fading away, dumping 260 billion metric tons of water into the ocean every year. The ocean acidification is occurring at a rate faster than at any time in the last 300 million years, and the patterns of rainfall and drought are changing and undermining food security which have major implications for human health, welfare and social infrastructure. These atmospheric changes follow an upward trend in anthropogenically induced CO2 and CH4.
The first scientists that explored the relationship between carbon dioxide concentrations in the atmosphere and global warming were Svante Arrhenius and Thomas Chamberlain at the end of the nineteenth century. Now, the current rate of increase of CO2 emissions has no precedent in the geological record and there is no perfect analogue from the past for the temporal evolution of future climate. However, we still can learn from historical and archeological records how societies had responded in the past to the unintended consequences of human action on the environment.
Human activity took precedence over natural climate change as the driving force behind plant and animal extinctions with the advent of agriculture and the domestication of animals. There are several cases in the past where anthropogenic environmental change has caused the collapse of economic, social and political systems. A good example of that is the collapse of Classic Maya political centers between AD 750 and 1000.
Paleoecological records indicate that the transition to agriculture was a fundamental turning point in the environmental history of Mesoamerica. Tropical forest were reduced by agricultural expansion associated with growing human populations. Also soil loss associated with deforestation and erosion was one of the most consequential environmental impacts associated with population expansion in the Maya lowlands (Kennett, 2013). This environmental crisis ended with the collapse of the Classic Maya society.
Today the most politically unstable countries are also places where environmental degradation affected food production and water supply. Other human societies have succumbed to climate change – like the Akkadians – while others have survived by changing their behavior in response to environmental change. We have opportunity to protect the future of our own society by learning from the mistakes of our ancestors. International cooperation is one of the keys. As Trevor Manuel, a South African government minister and co-chair of the Global Ocean Commission stated: “Governments must respond as urgently as they do to national security threats – in the long run, the impacts are just as important”.
Kennett, D.J., Beach, T.P., Archeological and environmental lessons for the Anthropocene from the Classic Maya collapse. Anthropocene (2014), http://dx.doi.org/10.1016/j.ancene.2013.12.002
M. Morlighem, E. Rignot, J Mouginot, H. Seroussi, and E. Larour. Deeply incised submarine glacial valleys beneath the Greenland Ice Sheet. Nat. Geosci., 2014
Malcolm McMillan, Andrew Shepherd, Aud Sundal, Kate Briggs, Alan Muir, Andrew Ridout, Anna Hogg, Duncan Wingham. Increased ice losses from Antarctica detected by CryoSat-2. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL060111
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