**2. Climates, change, and changing climates**

If one listens to or reads the media of journalists, commentators, and public servants (particularly politicians)—people from whom the public normally receives new information and upon which they (often) base their understanding of their lifeworld—it is evident that few of the messengers have accurate and clear grasps of the concept "climate," and yet they have a deep desire or feeling of responsibility to provide a clear explanation of climate to the public [10, 11]. The most egregious misapprehension of climate is that Earth has one (and only one). Our planet does not have "a climate." The climate is a conceptualization created to intellectually portray the combined conditions of temperature AND precipitation conditions of a region. Earth does have a "global" atmospheric temperature (this is how the globe's temperature can be said to be rising—global warming). But it is wrong to believe that there is a measure of global precipitation. In terms of water, Earth is a closed system. There is a fixed and finite amount of water on Earth and it circulates globally in all its forms (vapor, liquid water, and ice) constantly, we call this the hydrological cycle. Water changes state and spatial distribution continually because of seasons, atmospheric and oceanic circulation patterns, weather events, precipitation, evapotranspiration, and thermal conditions. The Earth has MANY climates. The number depends upon the mathematical detail, sophistication, and characteristics upon which climates are defined and distinguished.

The term "climate" is often (mis)used interchangeably with weather, particularly when people are talking about their personal, empirical (past and present) experiences of the conditions of the atmosphere in which they live. Their fundamental mistake is that they believe that it (climate) is a phenomenon, is tangible, that it is something "real" that people can viscerally experience, and that it can be sensed and measured in real-time. Climate, in fact, is not real. It is knowable through either of two methods: statistical analysis or inductive inference.

**5**

*Introductory Chapter: Climates, Change, and Climate Change*

Climates are usually defined statistically. Climate is a mental visualization, if you will, of atmospheric tendencies devised to explain the differences and similarities between (large and small) terrestrial (i.e., land) regions of the world. A climate-classification system allows one to categorize climates by averages and ranges of temperatures, available moisture, and weather phenomena over (*at least*) 30-year periods. The most meaningful climate-classification schemes are based on large datasets containing long records (again, at least three decades' worth) of weather data distributed over Earth's terrestrial surface (oceans do not have climates in our conceptualization). Daily thermal and precipitation records are used to characterize "normal" weather conditions (i.e., tendencies) at and near each weather station (which are proxies for larger zones in lieu of a dense array of instruments measuring the atmosphere). Climates are also characterized by means, extremes, and seasonal patterns distinguished as regular occurrences of major shifts, or of extreme conditions, like frosts or freezes, monsoons, and hydrological droughts that occur annually. Why were climates created? The most basic need was to discern the opportunities and challenges one might expect for day-to-day and long-term survival and comfort. Having and knowing climates establishes a basis upon which we can consider our life-prospects, particularly for planning future activities (getting water, growing or gathering food, keeping our bodies healthy and maintaining

our comfort) in the context of weather and seasonal weather patterns.

Climate statistics, however, do not magically reveal the implications of weather data. Even long ago, when Greeks talked about torrid, temperate, and frigid zones, they were reflecting on the prospects for or challenges of life in other regions of the world (naming parts as "summer-less," "intermediate," and "winterless" might predict opportunities and limitations for agriculture). Modern climates are much more sophisticated and more complicated, as is our need to know whether our more sophisticated and more complicated activities can be safely or profitably conducted in places around the world. In the absence of weather data upon which a classification schema can be based, scientists and nonscientists before them inferred climate conditions based on the empirical evidence on the ground, particularly on the vegetation, the least mobile occupant of any environment. The vegetation that grows anywhere can logically be regarded as the plants that have survived the conditions in that place. By observing the compositions of plant communities and considering each plant's characteristics (anatomy, physiology, and hardiness), one might inductively determine (using higher order, more sophisticated understanding of plant biology) the thermal and hydrological conditions that have prevailed in that place. Major ecosystem types are often associated with (and they even supply the names for) the spectral product of these variables: rainforest, tropical savanna, desert, steppe, and tundra are terms that are often used to identify "climates." So, it might not be difficult to understand how someone might believe that because plants are used to name climates and because plants are evident in the landscape, climate must be apparent … visible. We must be capable of perceiving climate right now. The problem is, looks and logic can be deceiving. Some plants have features that may fit well in other places, in other ecosystems. Plants can be unnatural (due to invasion) in a place, perhaps promoted by natural and unnatural disturbances of landscapes. Some plants might have been introduced from other regions with markedly different climates. Transplants or invaders may be found outside of their normal zones, supported artificially for aesthetic purposes. Plants are not

*DOI: http://dx.doi.org/10.5772/intechopen.92192*

**2.2 Knowing climate through inference**

**2.1 Knowing climate statistically**
