West Nile Virus is Moving Up in the World
Global temperatures are rising. You hear this all the time because, based on certain numbers, it's true. But what are these numbers? The metric used by NASA's Goddard Institute for Space Studies (GISS) and the National Oceanic and Atmospheric Administration (NOAA) is the "global mean surface temperature anomaly". Sounds like something made up to give Spock some dialogue. But it just means how much hotter the Earth is compared to a long-term average. What average? To test if current years are unusually warm, scientists usually compare them to the average global surface temperature between 1951 - 1980. We have solid data for those years. Anytime before that, data wasn't as accurate or consistently gathered. Although, you might see a "pre-industrial baseline" which covers 1850-1900. Oddly enough, the average global surface temperature in both periods was around 57°F. Things weren't changing all that much. Until now. Using either baseline, each of the pa...
