The past year was the hottest on record since at least 1891, the Japan Meteorological Agency (JMA) announced on January 5th. The JMA reports that the average temperature was 0.27°C warmer than the 1981 to 2010 baseline average. (1)
This finding was not unexpected. In December 2014, the United Nations’ World Meteorological Organization released a preliminary analysis of temperatures from January through October 2014, indicating a potential record-setting year, which the United Kingdom’s Met Office and the United States National Oceanic and Atmospheric Administration supported.
High temperatures in 2014 helped contribute to the California drought.
2014 is also notable for the absence of El Niño, a weather pattern occurring in the Pacific Ocean that warms surface waters and raises air temperatures. The three previous hottest years on record, 2010, 2005, and 1998, had gotten a boost from El Niño. Michael Oppenheimer, a climate scientist at Princeton University, says “it is surprising to have record heat in a year without strong El Niño” and adds that it is a reminder that the Earth is heating up quickly. (1)
The new high comes after more than a decade during which the rate of temperature rise slowed. This “warming hiatus” began around 1998, following a strong El Niño that year. The average global temperature rose by 0.05°C from 1998 to 2012, compared to 0.12°C per decade from 1951 to 2012.
Although El Niño is generally thought to warm the climate, some researchers have suggest that the strong El Niño in 1998 changed heat absorption in the Pacific Ocean, contributing to the warming slowdown. (2) Other researchers disagree that this period should be called a hiatus. Anthony Barnston, chief forecaster at the International Research Institute for Climate and Society at Columbia University, says, “the theory is that rather than a hiatus, the warming temperatures have been collecting in the bases of oceans instead.” (1)
It should be noted that the JMA’s data shows 2014’s high to be 0.05°C higher than the previous record and does not indicate a major change in the continuing warming trend. However, it still indicates that climate change is indeed happening, regardless of magnitude.
Sources:
1. Deng, B. (2014). 2014 was the hottest year on record. Nature. Retrieved from http://www.nature.com/news/2014-was-the-hottest-year-on-record-1.16674
2. Trenberth, K. E. and Fasullo, J. T. (2013). An apparent hiatus in global warming?. Earth’s Future, 1: 19–32. doi: 10.1002/2013EF000165