Another month passes and another dataset gathered and interpreted by NASA scientists reinforce an alarming trend. The agency's latest monthly analysis of global temperatures has found August 2016 to be the hottest August in 136 years of record-keeping, marking the 11th consecutive month such a record has been broken.
Scientists at NASA's Goddard Institute for Space Studies (GISS) in New York carried out their analysis by collating data from about 6,300 meteorological stations around the world, along with instruments that track sea surface temperatures and Antarctic research stations.
August of 2014 was the previous record-holder, but the team found this year's August to be 0.16 °C warmer (0.28 °F) and tied July 2016 as the hottest month on record. It was also 0.98 °C (1.76 °F) warmer than the mean August temperature between 1951 and 1980.
With so many consecutive months of record-breaking temperatures, it follows that Earth is being subjected to above-average temperatures for sustained periods of time. The first half of 2016 was the globe's hottest six months on record. This coincided with record-breaking shrinkage of Arctic sea ice, where total coverage at the peak of melting season is now 40 percent lower than in the late 1970s.
There is climate trouble at the other end of the globe too, with atmospheric concentration of carbon dioxide, the main reason for the warming trend, passing the 400 parts per million (ppm) mark over the South Pole in May this year (also the hottest May on record). 350 ppm is a level experts consider safe, and the far Southern Hemisphere was the last place on the planet to be tipped over this already generous 400 ppm threshold.
"Monthly rankings, which vary by only a few hundredths of a degree, are inherently fragile," says GISS Director Gavin Schmidt. "We stress that the long-term trends are the most important for understanding the ongoing changes that are affecting our planet."