Mammoth climate change
Before humans discovered the joys of rooting about with crops, we were hunters and gatherers. While this way of living did not lend itself to the development of shopping malls it did minimise traffic jams and left a small environmental footprint.
Around seven millennia ago when humans began planting crops the realised that they wanted more land to do it. That was the beginning of deforestation as land was cleared for fields and was believed until now to have been the first major impact of human beings on climate. Now a new study has suggested that humanity may have had a mammoth effect on climate change before agriculture began.
For the study researchers analysed pollen records in Alaska, Siberia, and the Yukon Territory of Canada. This was the habitat of the woolly mammoth. They also assessed the behaviour of modern day elephants and looked at temperature changes on the planet from around 15 000 years ago.
The results showed that the demise of the mammoths coincided with a rise in temperature in northern areas of an average of 0.2 degrees Celsius, although some areas had a rise of one degree Celsius. If the hunting of mammoths by human beings contributed to the mammothâ€™s decline, as is suspected, then this was probably the first discernible impact that humanity had on the Earthâ€™s climate.
The decline of the vegetation-chomping mammoths resulted in a proliferation of dwarf birch trees around the Arctic. This northward march of vegetation is known as the â€œalbedo effectâ€, in which white, reflective snow and ice is replaced with darker land surfaces that absorb sunlight and create warming. This suggests that human activities in hunting mammoths had an impact on climate before any fossil fuels began being burned.
The scale of the impact of this was not huge compared to modern day human induced changes. Since the beginning of the 20th century Earth temperatures have risen by 0.74 degrees Celsius. The point however, is that human beings do impact their climate. To argue otherwise is specious and may in fact be arguing for inaction that could be disastrous.