In addition to the internal variability of the global climate system itself, there is the added factor of external influences, such as volcanoes and solar activity.
In 1832, the year of Michael Faraday's discovery that a changing magnetic field produces an electric field, a young French engineer patented a new and more efficient waterwheel.
It may be possible for large-scale change to occur without leaders with magnetic personalities, but the pace of change would be slow, the vision uncertain, and the committee meetings endless.
The efficacy of antimicrobials varies over time and from country to country in response to antimicrobial use patterns and movement of organisms between communities.
This book will provide a detailed examination of the Little Ice Age and other climatic shifts, but, before I embark on that, let me provide a historical context.
The climatic changes in southwestern Asia were more subtle, in that they involved shifts in mountain snow lines, rainfall patterns, and vegetation cover.
The flotation samples from the excavations allowed botanists to study shifts in plant-collecting habits as if they were looking through a telescope at a changing landscape.