Wednesday, January 27, 2016

El Nino/La Nina and Global Warming

As I've explained, El Nino and La Nina, together called ENSO, are changes in global temperatures on top of the secular trend from the increasing greenhouse gases in the atmosphere.  As I've pointed out, and as described here, 2016 will almost certainly be an even hotter year than 2015.  

 Here is a graph that visualizes these trends

ENSO temps GIF
Berkeley Earth average global surface temperatures since 1965 categorized by type of El Niño year. Illustration: Dana Nuccitelli

As NASA GISS director Gavin Schmidt said,
The El Niño that we’re seeing is starting at the end of 2015, and so there hasn’t been enough time for that to really have an impact on the annual mean temperatures. So 2015 was warm even though there was an El Niño, and it would’ve been a record year even if you abstract out the El Niño affect, 2015 would’ve been a record warm year by a long chalk.
And due to the aforementioned lag, 2016 could be even hotter yet. Prof Adam Scaife, head of long-range forecasting at the Met Office, said in an interview with Carbon Brief,
Given the strength of the current El Niño, we expect 2016 to be even warmer globally than 2015. The lagged effects of El Niño are already starting to appear in the monthly temperature observations, which are registering more than 0.8 degrees above norm in recent months. This is consistent with our forecast for unprecedented warmth in the coming year. Overall, we expect El Niño to contribute around 25% to what will most likely be a new record global temperature in 2016. Much of the rest is down to climate change.
If 2016 breaks the temperature record yet again, it will be the first time in the past 150+ years that three consecutive years set a new annual global temperature record.