The Context for ‘Record’ Global Mean Temperatures
Last week, Earth saw its warmest estimated mean temperatures. The media stretched the truth, reporting it as official observations.
As heat waves are sweltering the United States, the planet saw an unofficial, estimated warmest global average temperature for three days straight last week. The story broke from the Associated Press (AP) and was quickly picked up by dozens of local news agencies.
The only problem is many of these local news agencies seemed to omit the “unofficial record” or “estimated” parts from their headlines, misleading readers in treating the estimated average temperatures as actual observations.
“Earth’s hottest day record set, reset three times this week,” a Dallas-based NBC station reported. “The planet saw its hottest day on record this week,” stated CNN. Many other news outlets committed the same thing. To its credit, the AP was innocent of this misleading headline.
The Climate Reanalyzer
The claim rests upon products provided by the University of Maine’s Climate Reanalyzer, a visualization tool that graphs outputs from reliable NOAA climate model estimations. This tool is incredibly useful when looking at a snapshot of the current state of the climate however, its products do not reflect official numbers or observations and shouldn’t be used as such.
In particular, the Daily 2-Meter Air Temperature visualization provided by the website utilizes NOAA’s Climate Forecast System. This system models interactions between the oceans, land, and atmosphere, providing hourly estimated data on a variety of factors. The Climate Reanalyzer visualizes this data in an easy-to-read format, unfortunately making it easy to take out of context.
The Climate Reanalyzer visualizes estimated temperatures, not observed temperatures. This alone calls into question the validity of recent headlines.
The increased attention due to the highest temperature estimation in its relatively short history prompted the website to include a special notice: “The increase in mean global temperature since the start of July, estimated from the Climate Forecast System, should not be taken as an ‘official’ observational record.”
It is important to note, NOAA’s Climate Forecast System is a fairly reliable model. So, while the estimated global temperatures are the warmest to ever be recorded, it is possible, although not a factual guarantee, that the planet in turn had its warmest global mean temperature.
Official Mean Global Temperature
While record daily temperatures are kept for towns, counties, cities, and countries, no such record is officially in place for the daily global mean temperature. There is simply too much variability in the day-to-day and location-to-location measurements to maintain such a record on a daily, global scale.
Rather, NOAA maintains monthly and annual observational records, which are considered part of the official climate record. The official record dates back nearly 200 years. The report for July has not yet been released, as these developments have occurred during this month.
Global Context for Recent Warmer Temperatures
There are three relatively recent developments in global climate and weather systems that can provide insight into recent elevated temperatures.
For one, the recent development of El Nino has naturally led to warmer Pacific waters remaining at the surface, contributing to a warmer atmosphere.
Secondly, the Atlantic Ocean has seen significantly warmer-than-average temperatures this year, in part thanks to the naturally occurring warmer phase of the ocean’s circulation, but also due to rising global temperatures.
Thirdly, weather patterns in the Southern Hemisphere have brought warmer air masses over the Antarctic region, offsetting one of the coldest parts of the planet, temporarily resulting in slightly increased global average temperatures.
These three developments are on top of a multitude of factors impacting global warming.
It is important to be aware of the context surrounding claims made by the media, especially as it pertains to the climate and extreme weather. Occurances often have further explanations and are not necessarily as bad as it is made to seem.
