Do your recent weather memories include an unnaturally high number of heatwaves, droughts, and record-breaking temperatures? It wasn't just your imagination: 2014 was one of the hottest years experienced by nearly everyone currently living on the planet.
The many records set in 2014 included land temperatures, ocean temperatures, sea levels, and greenhouse gas levels, according to the State of the Climate 2014 report, which was published this week in the Bulletin of the American Meteorological Society. These indicators and many others continue to prove that the planet is warming, the study concludes.
The report's data comes from 413 independent scientists in 58 countries and is compiled by the National Oceanic and Atmospheric Administration. Since the organisation has been compiling the same data from the same places for 25 years, it can definitely see some clear trends, says Thomas R. Karl, director of NOAA National Centres for Environmental Information:
"This report represents data from around the globe, from hundreds of scientists and gives us a picture of what happened in 2014. The variety of indicators shows us how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere."
Of particular concern are 2014's temperature extremes, which are a measure of how often the temperature recorded in any given place was warmer or colder than average.
As you can see from these maps, many places in the world saw an exceptionally high frequency of warmer than average days last year. The only place that saw more cold temperature extremes was the Eastern US and Canada.
When the data is laid out since 1961, the trend becomes very clear. We are experiencing more record-hot days and fewer record-cold nights.
Here are some of the other highlights (lowlights?) from the report. I've quoted the study directly for each:
Record temperatures observed near the Earth's surface: "Four independent global datasets showed that 2014 was the warmest year on record. The warmth was widespread across land areas. Europe experienced its warmest year on record, with more than 20 countries exceeding their previous records. Africa had above-average temperatures across most of the continent throughout 2014, Australia saw its third warmest year on record, Mexico had its warmest year on record, and Argentina and Uruguay each had their second warmest year on record. Eastern North America was the only major region to experience below-average annual temperatures."
Sea surface temperatures were record high: "The globally averaged sea surface temperature was the highest on record. The warmth was particularly notable in the North Pacific Ocean, where temperatures are in part likely driven by a transition of the Pacific decadal oscillation — a recurring pattern of ocean-atmosphere climate variability centered in the region."
Global sea level was record high: "Global average sea level rose to a record high in 2014. This keeps pace with the 3.2 ± 0.4 mm per year trend in sea level growth observed over the past two decades."
Greenhouse gases continued to climb: "Major greenhouse gas concentrations, including carbon dioxide, methane and nitrous oxide, continued to rise during 2014, once again reaching historic high values. Atmospheric CO2 concentrations increased by 1.9 ppm in 2014, reaching a global average of 397.2 ppm for the year. This compares with a global average of 354.0 in 1990 when this report was first published just 25 years ago."
Shallow melt ponds on the surface of the consolidated sea ice pack in the Chukchi Sea in July 2011, photo by NOA