NASA — Last year was the fourth warmest year on average for our planet since the late 1800s, according to NASA scientists.
To determine if the Earth is warming or cooling, scientists look at average temperatures. To get an “average” temperature, scientists take the warmest and the coolest temperatures in a day, and calculate the temperature that is exactly in the middle of those high and low values. This provides an average temperature for a day. These average temperatures are then calculated for spots all over the Earth, over an entire year.
Scientists use temperatures taken on land and on surfaces of the oceans. Weather stations provide land measurements, and satellites provide sea surface temperature measurements over the ocean. These data are computed by NASA. —Earth Gets a Warm Feeling All Over (Red Nova)
OMG! Look, Ethel, at that big red blob over North America! We must be frying in hell!
The article doesn’t tell us what we’re looking at, but one assumes from context that the hotter colors on the map show areas of increased heat. But another map, the “2004 Annual Mean Surface Temperature Anomalies,” shows that the area over North America to be anywhere from .5 to 2.7 degrees cooler in 2004 than it was five years earlier.
The article is fine. The pictures are cool. They don’t go together, however.
Imagine how different the visual rhetoric would be if this image of the globe instead showed mostly pale green, with a slightly more yellow green indicating raised temperature. The red creates an emotional reaction.