1934 is the hottest year on record

What The Science Says:
Globally the year 1934 was cooler than the 20th century average.

Climate Myth: 1934 - hottest year on record
Steve McIntyre noticed a strange discontinuity in US temperature data, occurring around January 2000. McIntyre notified NASA which acknowledged the problem as an 'oversight' that would be fixed in the next data refresh.  As a result, "The warmest year on US record is now 1934. 1998 (long trumpeted by the media as record-breaking) moves to second place." (Daily Tech).


The year 1934 was a very hot year in the United States, ranking sixth behind 2012, 2016, 2015, 2006, and 1998. However, global warming takes into account temperatures over the entire planet, including the oceans. The land area of the U.S. accounts for only 2% of Earth's total surface area. Despite the U.S. sweltering in 1934, that year was not especially hot over the rest of the planet, as you can see on the 1934 map below. Globally, 1934 temperatures were actually cooler than average for the 20th century.

1934Global T map 1934

2016global T map 2016

Figure 1. Global temperature maps for 1934  (top) and 2016 (bottom). Source NASA.

Climate change skeptics have pointed to 1934 in the U.S. as proof that recent hot years are not unusual. Choosing the year 1934 is an obvious example of "cherry-picking" a single fact that supports a claim, while ignoring the rest of the data. In fact they have to cherry pick both a location (the U.S.) and a year (1934) to find data that is far from the global trend. Globally, the years 2014, 2015 and 2016 are the hottest on record, so far.

Global T anomalies


Figure 2. Global land and ocean temperatures from 1880 to 2015. Source: National Climate Data Center


The fact that there were hot years in some parts of the world in the past is not an argument against global climate change. Regional and year-to-year temperature variations will always occur. The reason we are worried about climate change is that on average, over the entire world, the long term trend shows an undeniable increase in global surface temperatures and global ocean temperatures. This rapid global heating is dramatically altering the planet we live on.



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