Ag Weather Forum
New Record Warmth in July
The world July climate report was issued by the National Oceanic and Atmospheric Administration (NOAA) this week -- and the big takeaway is that warming around the earth -- yes, global warming -- continues. There were some relatively cooler areas, but they were small in number compared to the rest of the globe.
Here are some highlight text comments from the report:
The year-to-date temperature combined across global land and ocean surfaces was 1.53 degrees Fahrenheit (0.85 degrees Celsius) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record set in 2010 by 0.16 deg F (0.09 deg C).
The year-to-date globally averaged land surface temperature was 2.41 deg F (1.34 deg C) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record of 2007 by 0.27 deg F (0.15 deg C).
The year-to-date globally averaged sea surface temperature was 1.21 deg F (0.67 deg C) above the 20th century average. This was also the highest for January-July in the 1880-2015 record, surpassing the previous record of 2010 by 0.11 deg F (0.06 deg C). Every major ocean basin observed record warmth in some areas.
The combined average temperature over global land and ocean surfaces for July 2015 was the highest for July in the 136-year period of record, at 0.81 deg C (1.46 deg F) above the 20th century average of 15.8 deg C (60.4 deg F), surpassing the previous record set in 1998 by 0.08 deg C (0.14 deg F). As July is climatologically the warmest month of the year globally, this monthly global temperature of 16.61 deg C (61.86 deg F) was also the highest among all 1627 months in the record that began in January 1880. The July temperature is currently increasing at an average rate of 0.65 deg C (1.17 deg F) per century.
P[L1] D[0x0] M[300x250] OOP[F] ADUNIT[] T[]
(The previous paragraph is worth noting. Comments about the Earth's warming trend having slowed or stopped since 1998 can be put to rest. -- BA)
The full report is available here: http://goo.gl/…
Also, the global warming connection to the historic and devastating drought in the Far West was highlighted in a peer-reviewed paper sent out this week. The paper is titled "Contribution of anthropogenic warming to California drought during 2012-2014." It is authored by a team comprising four scientists from Columbia University and one from the University of Idaho.
Here is the abstract summary:
"A suite of climate datasets and multiple representations of atmospheric moisture demand are used to calculate many estimates of the self-calibrated Palmer Drought Severity Index, a proxy for near-surface soil moisture, across California from 1901-2014 at high spatial resolution.
Based on the ensemble of calculations, California drought conditions were record-breaking in 2014, but probably not record-breaking in 2012-2014, contrary to prior findings. Regionally, the 2012-2014 drought was record-breaking in the agriculturally important southern Central Valley and highly populated coastal areas.
Contributions of individual climate variables to recent drought are also examined, including the temperature component associated with anthropogenic warming.
Precipitation is the primary driver of drought variability but anthropogenic warming is estimated to have accounted for 8-27 percent of the observed drought anomaly in 2012-2014 and 5-18 percent in 2014.
Although natural variability dominates, anthropogenic warming has substantially increased the overall likelihood of extreme California droughts."
The lead author of this letter, A. Park Williams of the Lamont-Doherty Earth Observatory at Columbia University, told the New York Times that the air over California can absorb about 8.5 trillion more gallons of water in a typical year than would have been the case in the cooler atmosphere at the end of the 19th century.
Bryce
Twitter @BAndersonDTN
(AG)
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