Even before the advent of agriculture, Homo sapiens kicked off an entirely new process of planetary change. Earth would never be the same. Instead of mere centuries, Erle C Ellis advances a broader view of the Anthropocene, over many millennia, and what that means for land stewardship.
The rise and fall of the ancient Maya has intrigued historians and archaeologists for decades. Now, Earth-system scientists are taking a keen interest. Scott Heckbert asks: what role might environmental conditions and trade play in the growth and eventual collapse of a civilisation?
Earth behaves as a complex system. Complex systems can respond abruptly to changes within the system - these abrupts changes can be highly non-linear. There is strong evidence that the Earth system is prone to such abrupt changes.
Human-induced global change has pushed the Earth system into a no-analogue state — where climatic and other environmental conditions are outside of the range of the last half million years (at least), increasing the likelihood of unpredictable changes with potentially harmful consequences. Exploring and quantifying Earth system interactions is therefore extremely important. The Earth system perspective demands a new scientific approach and innovative conceptual and technical tools. Separate Earth system components, properties and processes — such as the composition and circulation pattern of the atmosphere — still need to be investigated, but should be studied as integral parts of a system, so as to understand their interactions and feedbacks. Furthermore, in the era of global change, humanity must also be considered a part of the Earth system. Indeed, IGBP includes the human social, cultural and economic systems as within the Earth system.
This issue’s cover story puts 2000 years of regional temperature histories into perspective. Also featured: two full-spread maps visualising the PAGES 2k regional temperature records and ocean acidifi...