2.2 Changes in local and extreme temperatures

Small shifts in average temperatures can mean the local extreme high temperatures become unbearable for humans and other species living in areas with climates that are already challenging

Figure 5 shows a map of the observed surface temperature changes from 1901 to 2012 (IPCC, 2013).

Figure 5 Map of the observed surface temperature change from 1901 to 2012 (IPCC, 2013). Trends have been calculated where data availability permits a robust estimate, while other areas are white, indicating there is not enough data. Grid boxes where the long-term change is significantly larger than the short-term fluctuations are indicated by a + sign.

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This map is colour coded in square cells on a grid, mostly with crosses in each cell, to show the change of temperature over the globe. Data points are over land and oceans. Most regions show temperature increases over 0.20 °C, some as high as 2.5 °C (including central Asia and parts of west Africa and Brazil). There are some decreases e.g. in the ocean South of Greenland. Some areas are white, largely Antarctica, the polar oceans and some regions of the Pacific Ocean and Africa.

Figure 5 Map of the observed surface temperature change from 1901 to 2012 (IPCC, 2013). Trends have been calculated where data ...

Many regional changes have been more than double the global average. Figure 5 shows that changes in large regions of South America and Eurasia have been around 2°C since 1900. This is still not the complete picture: in white regions, there are not enough data to reliably calculate the long-term trend since 1901. This includes most of the northern Arctic regions, where the available measurements show that warming has been greatest.

Global warming shifts the distribution of temperatures. Since 1950, hot days and nights have generally become warmer and more frequent, while cold days and nights have become warmer and less frequent (IPCC, 2013).