The “Average Temperature Anomaly – Global” graph in figure 2 shows the increase in global average temperature relative to the average of the period between 1961 and 1990. The red line represents the average annual temperature trend through time, with upper and lower confidence intervals shown in light grey.
It’s evident that over the last few decades, global temperatures have risen sharply. They are approximately 0.7℃ higher than the 1961-1990 baseline. Records show that temperatures, extended back to 1850, were an additional 0.4℃ colder than the 1961-1990 baseline. This amounts to an average temperature rise of 1.1℃.
The specific temperature increase depends on the year we assume to be ‘pre-industrial’ and the end year we’re measuring from due to the small year-to-year fluctuations in temperature,
Overall, the temperature rise is in the range of 1 to 1.2℃. In the interactive version of this chart – using the “Change region” button you can also view these changes by hemisphere (North and South), as well as the tropics (defined as 30 degrees … Continue reading.
|↑1||In the interactive version of this chart – using the “Change region” button you can also view these changes by hemisphere (North and South), as well as the tropics (defined as 30 degrees above and below the equator). This shows us that the temperature increase in the North Hemisphere is higher, at closer to 1.4℃ since 1850, and less in the Southern Hemisphere (closer to 0.8℃). Evidence suggests that this distribution is strongly related to ocean circulation patterns (notably the North Atlantic Oscillation) which has resulted in greater warming in the northern hemisphere|