{"id":25515,"date":"2016-03-23T11:00:33","date_gmt":"2016-03-23T00:00:33","guid":{"rendered":"http:\/\/www.aspistrategist.ru\/?p=25515"},"modified":"2016-03-23T12:25:38","modified_gmt":"2016-03-23T01:25:38","slug":"a-monster-of-a-month","status":"publish","type":"post","link":"https:\/\/www.aspistrategist.ru\/a-monster-of-a-month\/","title":{"rendered":"A monster of a month"},"content":{"rendered":"
The global average temperature anomaly was <\/span>1.35\u00baC<\/span><\/a> above the 1951\u201380 average and <\/span>1.21\u00baC<\/span><\/a> above the entire twentieth-century average. For temperatures over land, the deviation almost doubles to a whopping 2.31\u00baC above the twentieth-century average. <\/span>Other records<\/span><\/a> broken by February 2016 include the fact that it was the tenth consecutive month in which the global average monthly record was broken and that it completed the hottest three-month period on record (December 2015 to February 2016).<\/span><\/p>\n Normally, climate scientists don\u2019t get too anxious over a single month; our blood pressure tends to rise a bit more when record-breaking temperature anomalies are consistently smashed. But February is a special case\u2014not only did it set yet a new record in an increasingly concerning upwards trend, but\u00a0the\u00a0magnitude of the record is terrifying.<\/span><\/p>\n So what led to this monster of a month?<\/span><\/p>\n First, let\u2019s take a look at the possible influence of the <\/span>El Ni\u00f1o\/Southern Oscillation<\/span><\/a>. The 2015\u201316 El Ni\u00f1o was one of the <\/span>earliest<\/span><\/a> and <\/span>strongest<\/span><\/a> on record, easily comparable to its brother in <\/span>1997\u201398<\/span><\/a>. At the global level, El Ni\u00f1os can cause measurable increases in temperature. We saw this in 1998, in our hottest year on record to at the time: thanks to climate change, 1998 would have been a warm year without the El Ni\u00f1o, but the record set would have been smaller.<\/span><\/p>\n While the latest El Ni\u00f1o is <\/span>weakening<\/span><\/a>, its legacy is likely to have had a similar affect on our most recent hottest year on record (2015) and the monster February\u2014increasing the anomaly by just a little bit more than what climate change could achieve on its on. But there is no possible way that an observed El Ni\u00f1o, however strong, could solely explain such a huge monthly temperature deviation. Past El Ni\u00f1os have only intensified global average temperatures by up to <\/span>0.25\u00baC<\/span><\/a>, though the measured influence is usually smaller.<\/span><\/p>\n The second factor is the state of the Arctic, where the <\/span>sea ice extent<\/span><\/a> was more than 7 per cent below the 1981\u20132010 average, and the ice coverage the smallest since records began in 1979. Over relatively short timescales (monthly-seasonal) a lack of sea ice drives up temperatures. Ocean water is much darker than ice, so radiation from the sun that is normally reflected by the sea ice is absorbed, thus increasing temperatures.<\/span><\/p>\n Over longer timescales (years and decades), this sea ice\/temperature interaction drives itself\u2014increasing temperatures melt more ice, driving further increases in temperature\u2014through a process known as a positive feedback. Record-low Arctic sea ice during February 2016 and the associated extreme temperatures are consistent with the positive feedback interaction triggered by anthropogenic climate change.<\/span><\/p>\n This basic physical interaction drove regional temperatures to well over\u00a0<\/span>11.5\u00baC warmer<\/span><\/a> than the 1951\u201380 average. These alarmingly warm conditions were not just confined to the Arctic waters. Due to the influence of sea ice (or the lack of it) on atmospheric circulation, similar temperature extremes were measured well south of the Arctic Circle\u2014over Northern Europe, Russia, Alaska and western Canada.<\/span><\/p>\n Other regions also sweltered. The December\u2013February average temperature over the <\/span>United States<\/span><\/a> was the highest since records began in 1895, with February itself the seventh highest. <\/span>Australia<\/span><\/a> experienced its ninth-warmest February on record, with the monthly mean temperature anomaly of 0.92\u00baC largely driven by warm daytime temperatures.<\/span><\/p>\n Once these regional figures are merged, it\u2019s easy to see how February was the hottest month on record, especially over land. It is also easy to see that the record was largely driven by <\/span>anthropogenic climate change<\/span><\/a>, with particular thanks to the shockingly strong positive feedback occurring in the Arctic. It\u2019s scary to think how much more temperatures will increase with further losses in sea ice. And even if we assumed the largest-ever influence of El Ni\u00f1o on global temperatures and removed 0.25\u00baC from the February anomaly (reducing it to 1.1\u00baC warmer than 1951\u20131980), the monster month would still be considered the warmest <\/span>February and one of the warmest months on record<\/span><\/a>.<\/span><\/p>\n The hottest on-record years in <\/span>2014<\/span><\/a> and <\/span>2015<\/span><\/a>, and predicted again for <\/span>2016<\/span><\/a>; the fifteen hottest years all occurring since <\/span>2001<\/span><\/a>; the consistently warmer than normal months for the <\/span>past thirty years<\/span><\/a>; the monster anomaly of February 2016\u2014it\u2019s no wonder that a <\/span>climate emergency<\/span><\/a> has been called by leading scientists.<\/span><\/p>\n All this means that we are heading towards the limits agreed to in Paris much faster than anticipated. February 2016 is making the 1.5\u00baC target look like a pipe dream, and putting 2\u00baC further out of reach. Indeed, even a target of <\/span>2.7\u00baC<\/span><\/a>, which is where current emission reduction pledges will take us, may not be met if we don\u2019t get to work soon enough. If we continue to consistently hit monthly records like February 2016, it means we have been too conservative on our estimates of the human impact on the global climate system. Thresholds like these were not meant to be reached for another <\/span>two to three decades<\/span><\/a>.<\/span><\/p>\n
\nMost people know by now that last month was the hottest February since modern records began. It was also the hottest overall month on record, and by <\/span>the largest margin<\/span><\/a>.<\/span><\/p>\n