Impressive data set shows July likely warmest of any month since 1850 worldwide

MLive - Mark Torregrossa

July is going to likely go down as the warmest month ever recorded in a global temperature dataset with observations back to 1850.

Berkeleyearth.org has produced their report on global temperatures for July 2020. One place I like to start on these reports is to just stare at the global temperature deviation map.

Temperature deviation from the July average of 1951 to 1980. (Source: berkeleyearth.org)

The map above shows how cold or warm July 2020 was from the long-term average July temperature. Notice we see a lot of red and not much blue.

More locations around the globe were in the warmest rankings for their locations versus locations in the coldest rankings. In fact, in just a few locations we had some of the coolest rankings.

Temperature rank in deviation from the 1951 to 1980 average (Source: berkeleyearth.org)

Analysis Berkeley Earth July 2020 is tied with July 2019 as the warmest July since records began in 1850. As July is usually the warmest month globally, tying the July record also means that July 2020 is tied for the warmest month overall. A transition towards La Niña conditions continue in the Pacific. Accounting for the likely impact of La Niña, updated projections for the rest of 2020 give a 36% chance that 2020 will be a new record warm year.

I talked with Zeke Hausfather, research scientist at berkeleyearth.org about the dataset.

It’s an impressive dataset they used for this report. They have merged several datasets together using 40,000 weather stations worldwide and 14,000 current weather stations.

Some of the weather stations have been reporting data back to 1850.

Hausfather addressed the often questioned reliability of changing technology over almost 200 years.

He says the U.S. temperature dataset had two big changes in technology to liquid and glass thermometers in the 1950s and digital thermometers in the 1980s.

If data just didn’t look consistent with surrounding stations, an individual station was taken out.

I relayed the often asked question of how jumps in technology could keep a consistent dataset.

Many feel like that jump to new technology could be the reason temperatures show up warmer. Zeke says the new technology was actually colder than older ways of reading temperatures.

Temperature deviation (in °C) from the 1951 to 1980 average global temperature. (Source: berkeleyearth.org)

Hausfather says what really strikes him is the very strong El Niño year of 1998, once the warmest year ever, is now colder than the last seven years.

Earth's average temperature by month back to 1850. (Source: berkeleyearth.org)

The funding for this report and other research at berkeleyearth.org comes from various organizations that are known to have opposite viewpoints on global warming.

Earth has warmed about two degrees Fahrenheit in the last 100 years, with much of that warming happening since 1980.

Links

• July 2020 Temperature Update - Berkeley Earth
• Last Decade Was Earth's Hottest On Record As Climate Crisis Accelerates
• 'Nowhere To Hide': South Pole Warms Up With Climate Change A Factor
• Global Warming Is Melting Our Sense of Time
• NASA Images Show Extreme Heat And Fires Raging Across Siberia
• Arctic Circle Sees 'Highest-Ever' Recorded Temperatures
• Earth Just Had Its Warmest May On Record Amid Startling Siberian Heat Wave
• Unsuitable For 'Human Life To Flourish': Up To 3B Will Live In Extreme Heat By 2070, Study Warns
• Climate Change Has Already Made Parts Of The World Too Hot For Humans
• Death Valley Temperature Rises To 54.4c – Possibly The Hottest Ever Reliably RecordedImpressive data set shows July likely warmest of any month since 1850 worldwide