With the first quarter of 2017 now past, the year is shaping up to be one of climate extremes: high temperatures, low sea ice, and coral bleaching.

The year is shaping up to be one of #climate extremes: high temps, low sea ice, and coral bleaching. Click To TweetGlobal surface temperatures continue to increase in-line with climate model predictions, and the world has now experienced an increased global temperature of about 0.8 degrees C (1.5 degrees F) since 1970. Temperatures for the first three months of the year were actually warmer than the 2016 average, and there is a reasonable chance that 2017 for a fourth consecutive year will be the warmest on record.

Global sea ice extent is near historic lows in the Arctic and Antarctic, and Arctic sea ice volume has also been decreasing as it ages and thins, with less new ice to replace it. The Great Barrier Reef experienced an unprecedented second consecutive year of coral bleaching, the only major coral bleaching on record to have occurred other than in an El Niño year.

Temperature

Global surface temperatures were surprisingly warm in the first quarter of 2017. Despite the end of the large 2015/2016 El Niño, temperatures remained high with January, February, and March each being the second warmest on record, after 2016. Average temperatures during the first three months of 2017 were warmer than the average of all months in 2016; taking into account the current El Niňo status and the historical relationships between January-March and annual temperatures, estimates are that there is about a 50/50 chance that 2017 will surpass 2016 as the warmest year on record.

Global average surface temps

The figure above shows the NASA global surface temperature record, combining weather station measurements over land with data from ships and buoys in the oceans. Temperatures have increased fairly consistently since 1970, the start of the “modern warm period” when the climate effects of human emissions became large enough to be judged the main driver of climate change. Much of the year-to-year variation can be explained by El Niño and La Niña events, which are associated with globally warmer and cooler temperatures respectively. The green dot represents the average of January through March 2017; the red dot and error bars represent the best prediction of full-year 2017 annual temperatures.

Global average monthly temps

Looking at estimates of global temperatures published in recent months by six different groups (NASA, NOAA, the U.K. Hadley Centre/MET Office, Berkeley Earth, Cowtan and Way, and the EU Copernicus project), one sees the large impact of El Niño in late 2015 and early 2016, followed by a fall in temperatures in late 2016 resulting from cooler La Niña conditions.

In recent months temperatures have increased in all the groups, though there is some disagreement between those estimating temperatures in large areas of the Arctic where measurements are limited (NASA, Berkeley, Cowtan and Way, and Copernicus) and those that do not (NOAA and Hadley).

Model ENSO predictions