We're living in one of the three hottest years on record
Meteorologist/Science Writer
Wednesday, November 8, 2017, 2:24 PM - Having delivered multiple extreme weather events so far, 2017 is on track to end up - exactly as predicted by climate scientists - in the top three hottest years on record.
After three years of back-to-back-to-back hottest years on record, 2017 has provided something of a respite, but according to a new report from the World Meteorological Organization (WMO), this year is still destined to end up in the top three hottest years on record.
According to the report, which is a preliminary work, based off weather records from January to September, puts 2017 at nearly half a degree Celsius (0.47oC +/- 0.08oC) warmer than the 1981-2010 average, which is around 1.1oC warmer than pre-industrial times.
Global temperatures, from the five leading temperature records. Credit: WMO
"The past three years have all been in the top three years in terms of temperature records. This is part of a long term warming trend," WMO Secretary-General Petteri Taalas said in statement.
"We have witnessed extraordinary weather, including temperatures topping 50 degrees Celsius in Asia, record-breaking hurricanes in rapid succession in the Caribbean and Atlantic reaching as far as Ireland, devastating monsoon flooding affecting many millions of people and a relentless drought in East Africa," he said. "Many of these events - and detailed scientific studies will determine exactly how many - bear the tell-tale sign of climate change caused by increased greenhouse gas concentrations from human activities."
What happened?
When we started out in 2017, no longer were we reporting month after month of record-breaking heat, primarily due to starting off the year in a weak La Niña pattern, which provided some cooling influence for the globe.
By comparison, in 2014-2016, there were either neutral ENSO conditions (in between El Niño and La Niña), or there was a strong influence by El Niño.
More neutral conditions taking over during the summer months of 2017 allowed temperatures to climb back towards record levels, but as we're set to go back into another weak La Niña by the end of the year, temperatures are projected to go down a bit farther in the months ahead.
Climate scientists were already saying that 2017 was unlikely to continue the trend we saw from 2014-2016, and as forecast, temperatures so far this year are showing that 2017 will likely land in 3rd place, behind 2016 and 2015 in the record books, but still warmer than 2014.
NOAA's month-to-month tally of year-to-date temperatures, as compared to the 20th century average, tracks how 2017 is shaping up compared to the top warmest years in the record books. Note that the 20th century average temperature is lower than the 1981-2010 average temperature, thus this NOAA graph reports higher temperature anomalies than the WMO graph presented above. Credit: NOAA NCEI
Different Extremes
While 2017 may not set any global temperature records, the WMO report catalogued several other climate extremes this year.
• The Accumulated Cyclone Energy (ACE) index, a measure of the cumulative intensity and duration of cyclones, reached its highest monthly value ever in September, mainly from Hurricanes Irma (Cat 5), Jose (Cat 4) and Maria (Cat 5)
• For the first time, ever, two Category 4 hurricanes - Harvey and Irma - made landfall in the U.S. during the same year
• Flooding impacted parts of Peru in March, killing 75 people and making 70,000 homeless. While these kinds of floods affect Peru during El Niño events, no El Niño pattern was present at the time. Despite this, temperatures just off the coast of Peru were El Niño-like, with surface water temperatures at over 2oC above normal
• Many parts of the Indian subcontinent were affected by monsoonal flooding, despite overall seasonal rainfall being near average
• Parts of east Africa continued to be seriously affected by drought. Following well-below-average rainfall in 2016, the 2017 “long rains” season (March to May) was also dry in many parts of Somalia, the northern half of Kenya, and southeastern Ethiopia
• An extreme heatwave affected parts of South America in January. In Chile, numerous locations had their highest temperature on record, including Santiago (37.4oC). In Argentina, the temperature reached 43.5oC on 27 January at Puerto Madryn, the highest ever recorded so far south (43oS) anywhere in the world
• Chile had the most significant forest fires in its history during the 2016-2017 summer, after exceptionally dry conditions during 2016 followed by extreme heat in December and January
• The area burned in the contiguous United States from January to 19 October was 46 per cent above the 2007-2016 average. The area burned in Canada was about 51 per cent above the seasonal average and contributed to heavy smoke pollution
"These findings underline the rising risks to people, economies and the very fabric of life on Earth if we fail to get on track with the aims and ambitions of the Paris Agreement," said Patricia Espinosa, Executive Secretary of UN Climate Change, which is hosting the COP23 climate conference in Bonn, Germany, this week.
"There is unprecedented and very welcome momentum among governments, but also cities, states, territories, regions, business and civil society," she added. "Bonn 2017 needs to be the launch pad towards the next, higher level of ambition by all nations and all sectors of society as we look to de-risk the future and maximize the opportunities from a fresh, forward-looking and sustainable development path."
