According to Patrick Lynch of NASA:
Based on [James] Hansen’s temperature analysis work at the Goddard Institute for Space Studies, the Earth’s average global surface temperature has already risen 0.8 degrees Celsius (1.4 degrees Fahrenheit) since 1880…
Those figures seem to understate the gravity of the situation since the number 1 is instinctively considered to be a small number. However, this temperature is a statistical average when spread out evenly throughout the whole earth. It is much more concentrated in some parts of the world which is causing weather disruptions throughout the rest of it.
The actual temperatures, as seen in the anomaly (Change in average) map below, are concentrated in the Arctic region. Temperatures there, in February of 2016, were as high as 20.16 degree Fahrenheit (11.2 Celsius)* above average compared to the period during 1951-1980. That month was the warmest winter month since temperature records began.
Figure 1: NASA’s GISS temperature anomaly map of the earth for the month of February, 2016. The color coded bar on the bottom indicates the above and below average temperatures in degrees Celsius. It goes up to 11.2C (20.16F). The number on the upper right corner indicates the rise in global average.
Below is a temperature map showing the average temperatures for the entire year of 2017. Please note that the intensity is much less than that of the previous map for February 2016. This indicates that global warming is concentrated not just in limited regions but in limited seasons throughout the year.
Figure 2: NASA’s GISS temperature anomaly map of the Earth for the year 2017. The average temperature difference for the whole earth, seen at the upper right of the map, is .9C or 1.62 Fahrenheit for that year.
Note that yearly temperature average in the map above is cooler than winter temperatures. This is because it is the winter temperatures that go up dramatically, much more so than spring, summer or fall. The nights are much longer in the winter and it is during nighttime that Carbon Dioxide retains the most heat.
Based on what has been happening throughout the past few decades we can expect that just a minor increase in the entirety of the earth’s temperature will concentrate in the Arctic regions even more so than at present.
This is more important than merely showing that global warming is progressing. Such a radical change in temperature in the Arctic regions creates a chain reaction of events that affect the weather below that region. The result is increased drought and flooding depending on the region.
*Each degree Celsius is 1.8 degrees Fahrenheit.