Earth rewrote record books in 2016 (not at all a good thing)
Meteorologist/Science Writer
Thursday, August 17, 2017, 5:13 PM - In a new international report, hundreds of scientists from around the world have now confirmed that 2016 was the hottest year ever recorded, in 137 years of record keeping. Here are the top five findings from the 2016 State of the Climate report.
In January, several world agencies, including NOAA, NASA and the Japan Meteorological Agency, flagged 2016 as the hottest year so far on record. Following 2014 and 2015, this was the third straight "hottest year on record" that we've seen in a row.
While the conclusions of these agencies were not in dispute, the official confirmation of where the year stands takes a bit more time, as scientists from around the world weigh in for the annual State of the Climate report, published by the Bulletin of the American Meteorological Society. By examining temperatures, precipitation patterns and amounts, plus changes in atmospheric circulations, ocean levels, snow cover, sea ice and glaciers, and going over the extreme weather events of the year, the goal of the report is to take stock of the global climate, based on all of these factors, and see how the year stacks up in the record books.
So, from over 400 leading scientists in the field, here are the top five findings of the report:
1) Earth's temperature is most certainly rising
Global temperature anomalies for 2016, compared to the 1981-2010 average. Credit: NOAA Climate.gov
Looking at global surface level temperatures and global ocean surface level temperatures, it's clear that we are seeing far more highs to extreme highs compared with lows to extreme lows, all over the world. If our climate were stable, we would see a much more even spread of highs and lows.
Global temperature rise, as compared to the 1981-2010 average, from 1900 to 2016. Credit: NOAA Climate.gov
Putting 2016 up against the rest of the climate record, going back to 1900, shows just how warm things have become, as we continue to pump more greenhouse gases into the atmosphere. Based on multiple data sets, 2016 now ranks as the hottest year in the modern climate record, pushing 2015 into the #2 slot and 2014 down into the #3 slot.
2) Heat waves and droughts have become worse
Graph of percentage of extreme hot days per year. Credit: NOAA Climate.gov
Map of drought intensity, across the globe, for 2016. Credit: NOAA Climate.gov
This isn't just about the average temperature of the planet creeping upward. The number of extremely hot days per year is on the rise, with 2016 coming in as a close second to 2015's record high. Meanwhile, 2016 represented the longest stretch of time, since the 1950s, with at least 12 per cent of the globe affected by drought conditions that were considered severe or worse.
3) Ice and snow are melting away
Arctic sea ice minimum, September 10, 2016, was the second lowest on record since 1979. Credit: NOAA Climate.gov
Along with Arctic sea ice in a statistical tie with 2007 for second lowest summer minimum on record, Antarctic sea ice saw a very unusual record low coming out of the 2016 southern winter. Combined together, this was the lowest yearly average for sea ice on record. Additionally, global snow cover was below average for the year, and 2016 marked the 37th year in a row of overall loss of ice from mountain glaciers.
Overall mass balance from 44 different mountain glaciers, shows that losses have exceeded gains for 37 years straight. Credit: NOAA Climate.gov
4) Ocean heat and meltwater are driving sea levels up
Global ocean temperature anomalies for 2016, compared to the 1981-2010 average. Credit: NOAA Climate.gov
Global sea level rise, between 1993 and 2016, also showing the estimated contribution from both meltwater and thermal expansion. The first half of 2016 brought the highest sea levels so far on record. Credit: NOAA Climate.gov
It's clear that the oceans are absorbing quite a bit of the heat that's being trapped in the environment by greenhouse gases, and this extra heat is adding to sea level rise, due to thermal expansion of the water. The global average amounts to just under 10 centimetres, which may not seem like much, but when this extra amount is added to high tides and storm surges, it can cause major problems. Not to mention that much larger rises have been measured on smaller scales, with many of these around high population regions, where they can impact far more people and cause much greater damage.
Global sea level anomalies in 2016. Note the rises measured near Japan, Indonesia and off the east coast of the United States, which are roughly twice the global average. Credit: NOAA Climate.gov
5) Carbon dioxide reached its highest concentration yet
Carbon dioxide concentrations, as measured at Mauna Loa, Hawaii, and globally. Credit: NOAA Climate.gov
We may have had some encouraging news lately about global carbon dioxide emissions being to level off, but even if the year-to-year amount being emitted isn't increasing (or isn't increasing by much), we are still adding a set or near set amount of carbon to the atmosphere, year after year. So, the overall concentration of carbon dioxide in the atmosphere is still on the rise, and in 2016 we saw the highest concentration so far - at 402.9 parts per million, global average, for the year.
Given that an average of 280 ppm has kept Earth's climate relatively stable for the past 800,000 years - long enough for humans and human civilization to develop to where we are now - adding an extra 40 per cent to that amount, in just over 100 years, is throwing the climate system seriously out of balance.
What's up for 2017?
2017 monthly temperature anomalies have been consistently 2nd or 3rd warmest on record, with July matching July 2016 for hottest month of July on record, according to NASA GISS. Due to different methods of data collection and processing, NOAA and JMA records place July 2017 as 2nd warmest on record, behind July 2016.
Although 2017 is unlikely to top 2016 to become the fourth "hottest year on record" in a row, the year is well on its way to displacing 2015 as the second warmest year on record.
Sources: NOAA Climate.gov | American Meteorological Society | NASA Earth
