World Climate Regions
A new approach for developing a new map of standardized global climate regions
Every location on Earth can be classified by its climate regime. The two most common and widely understood climate properties are the temperature regime and the moisture regime.
Temperature Regime:
Describes how hot or cold an area is during some time period (hour, day, month, season, year, decade, etc.). A long term temperature average for some location is calculated from temperature measurements spanning a very long time (many years). From the beginning, climatologists have used temperature ranges to classify and name temperature regimes, and the following temperature regime classes are common: Polar, Boreal, Cool Temperate, Warm Temperate, Subtropical, and Tropical.
Temperature Regime
While these are names for temperature regimes, they also suggest latitudinal variation as well, with the coldest temperatures normally associated with polar environments, and the warmest temperatures associated with tropical environments.
In addition to the temperature regime, the amount of precipitation that falls on a place is a second equally important attribute of climate.
Moisture Regime:
Describes how precipitation is associated with moister environments. A lot of precipitation is associated with moister environments, whereas limited precipitation results in drier environments. Areas with very little precipitation can be described as desertic environments. A simple classification of moisture regimes is Moist, Dry, and Very Dry (desertic).
Moisture Regime
The new map of World Climate Regions was produced using long term data on average temperature and average precipitation.
The temperature and moisture data were organized into the 18 different classes using standardized criteria endorsed by the Food and Agriculture Organization of the United Nations (FAO) and the Intergovernmental Panel on Climate Change (IPCC).
We followed, with modifications, the Intergovernmental Panel on Climate Change (IPCC) approach for climate region stratification, and the United Nations Food and Agriculture Organization (FAO) approach for delineating Global Ecological Zones
A Climate Region is an area of similar temperature regime and moisture regime.
When all possible combinations of temperature regime and moisture regime are optimized, the result is 18 World Climate Regions:
World Climate Regions
Since the temperature and moisture regimes determine in large measure what life can exist in a place, climate regimes are often referred to as bioclimates.
Bioclimates are understood as the most important factor influencing the distribution of living things, but terrain variables are also important, mainly because they modify macroclimates into mesoclimates and microclimates.
Roger Sayre, Ph.D., Senior Scientist for Ecosystems at the USGS Land Change Science Program, led a team from Esri and The Nature Conservancy to produce this global dataset. This work is documented in the publication below.
You can download the pro package to access the dataset from the Living Atlas
