Posted: Aug 09, 2016 9:04 pm
Macdoc wrote:Unprecedented global warming as 2016 approaches 1.5 °C mark
By Michael le Page
Global surface temperatures could get close to the 1.5 °C-above-preindustrial limit before the Paris climate agreement even comes into effect.
That’s alarming news, considering that the deal aspires to limit global warming to no more than this.
Last week Gavin Schmidt, head of NASA’s Goddard Institute of Space Studies, estimated that the average global temperature in 2016 could range from about 1.1 °C above preindustrial to only slightly below 1.5 °C, based on GISS’s temperature record and its definition of pre-industrial (other records and definitions vary).
https://www.newscientist.com/article/20 ... -5-c-mark/
Regarding the red: yes, they've already been through 1.5C over pre-industrial for short timeframes, including the month of the Paris agreement, and are likely to come in around 1.4C above for calendar 2016 using the GISS measure (anomaly from 1951-80 average + 0.4C).
As this is the peak year of a large El Nino event, that points to current trendline temperatures about 1.1C over pre-industrial, which at current warming rates would put the trendline past 1.5C sometime in the 2040's, which in turn would mean that future El Nino yearly averages may well break through 1.5C from the 2020's when the trendline temperature is over 1.25C or so above pre-industrial (depending on the size of the ENSO event, and how soon it occurs - over time it will take smaller and smaller El Nino events to break 1.5C over pre-industrial, and by 2050 it won't take an El Nino event at all, and could even happen in La Nina years.)
At 400ppm CO2, this is not avoidable, and the Paris agreement was criticised at the time it was made for including a long term 1.5C target that was plainly unachievable.
Regarding the green, it's not alarming news that with trendline temperatures of 1.1C above pre-industrial and rising that large El Nino peaks are hitting 1.4C above pre-industrial. It's just idiotic to focus on single years (or months) of a dataset containing much longer cycles like ENSO. If, during the next La Nina, we have a year that's only around 1.0C above pre-industrial, and someone argued that as 2016 had been close to 1.5C we'd obviously fixed the problem, what would you say to them?