Climate Change

Recent climate change

The Latter Half of the Little Ice Age

The 17th century was not just the time of the Little Ice Age, it is also noted (and for some better noted) for the Renaissance, which saw the gathering of scientific understanding that in turn was to drive the Industrial Revolution of the 18th and 19th centuries. In Britain in the 1640s and 1650s scientists sought what they termed ‘a great insaturation’, which drew on the philosophies exposed by the likes of Francis Bacon. Among these, Bacon's principles of exact observation, measurement and inductive reasoning provided the intellectual tools for scientific advance. These advances had yet to percolate through to day-to-day application in technology, so life, society and its economy were still largely powered by humans and animals together with the burning of wood. Major global impacts from human activity were not yet manifest (although, of course, trace global signatures such as metals in Greenland ice cores can be found dating to thousands of years earlier).

In terms of climate and weather, 1659 – within the Little Ice Age – is an important date. Before that date we rely solely on the proxy indicators (see Chapter 2) for climatic information. After 1659 there began a source of new information: direct meteorological measurement. The first significant series of measurements began in 1659 and (much later) were compiled into a monthly series of temperature readings for rural sites in central England by Gordon Manley (1974). This is the longest homogeneous record and is still kept up to date by the UK Meteorological Office. The earlier measurements were varied but increasingly included, and were soon dominated by, instrumental measurements. The Central England Temperature (CET) records were soon accompanied by others to ultimately be built into a series such as those for De Bilt in The Netherlands from 1705. Such records are fundamentally important. As we have seen, although we can use a variety of proxies to build up, piece by piece, quite a good picture of past climate, deep-time climatic proxy indicators simply are either not sensitive or representative enough to tell us what was going on. This is especially true with regard to finer changes. For example, ice-core isotopic records are very fine for charting regional glacial and interglacial transitions of a few degrees but are less useful for discerning trends in changes of fractions of a degree within our current interglacial.