The Earth Story

A July trip to Glacier National Park, with a filter applied that makes it feel like this could have happened 50 years ago...except there’s a lot less ice around now.

July 2015: Hottest month since temperature records began

In early August, we reported on the release of July temperature statistics from NASA’s Goddard Institute, one of several organizations that releases a monthly temperature summary (http://tmblr.co/Zyv2Js1sHu0vM). Since then, other groups have released their numbers, including NOAA, and their numbers include a very stark statement.

July 2015 was the warmest month since instrumental records began.

July is on average the warmest month during the year globally – it’s summer in the northern hemisphere and due to the arrangement of the continents and the currents in the ocean the middle of Summer for the Northern Hemisphere winds up being warmer than the Southern Hemisphere Summer.

We’re in the middle of the strongest El Niño event in almost 2 decades, and as a consequence we’re en route to the warmest year in the instrumental record. Putting all that together, July 2015 registered as the warmest year in recorded history, going back over a century.

July 2015 was 0.08°C warmer than the previous record holder for July. That may not sound like a whole lot, but it’s easily outside the margin of error of this measurement. The planet has warmed by about 1°C over the past century, and therefore that represents a jump equivalent to about a decade’s warming over the previous record holder, which occurred after the 1998 super El Niño.

Both the monthly and yearly marks being set in 2015 continue to be consistent with the rate of warming observed over the past century, with no obvious change in the planet’s response.

-JBB

Image credit: NOAA http://www.ncdc.noaa.gov/sotc/global/201507 http://www.ldeo.columbia.edu/res/div/ocp/pub/seager/Kang_Seager_subm.pdf http://www.cnn.com/2015/08/20/us/noaa-global-climate-analysis/

Hottest July on Record

Counting July there have been 7 months in the 2015 calendar year. Out of those, 5 months can be called the “hottest in recorded history”. The only months this year that didn’t break a temperature record were February and April.

This map comes from the NASA Goddard Institute, one of several major organizations that compile monthly temperature data worldwide. It shows the globally measured temperature in July as compared to the global average temperature recorded from 1951-1980.

Aside from it just being really, really hot, several major global weather features show up in this map. First and foremost, there’s a huge pool of heat off the equatorial coast of South America. This warm pool is the building 2015 El Niño event that we’ve been covering all year. This year’s El Niño already counts as a strong El Niño event and it is on pace to at least rival the 1997-1998 El Niño in intensity, if not beat it. This week the US News media finally found a name to describe how intense this event is shaping up to be – calling it a “Godzilla” El Niño event. I’m hoping I never type that phrase again.

In addition, you can see a warm pool in the Northern Pacific Ocean. This pool of heat has been affectionately nicknamed “the Blob” and it has dominated weather patterns in the Pacific area for several years. It has contributed to droughts and wildfires, deflecting rain away from the normal storm paths.

California has been stuck in a drought so long that they’re hoping this El Niño breaks the cycle as El Niño years typically are rainy areas in that part of the world. However, the presence of this huge pool of warm water in the Pacific is a new variable we haven’t seen before. In 1998 it wasn’t there. How the Pacific warm pool will interact with El Niño weather patterns is something I’m not sure anyone knows as we’ve never seen a super strong El Niño combined with a warm northern Pacific Ocean.

Barring the destruction of all measurement tools, it’s essentially certain that 2015 will be the hottest year ever measured. That’s how certain it is at this point.

The interesting questions for the remainder of the year are going to be things like how El Niño will interact with the global weather patterns and whether 2016 will wind up beating the 2015 temperature record. The last super-strong El Niño built in 1997 and the temperature record was then set in 1998; if that pattern holds then global weather disruption could continue for the next calendar year as this gigantic pool of warm water disperses.

Of course, as CO2 levels in the atmosphere keep going up, 2015 will also not be the last record breaking year we see.

-JBB

Image credit: NASA/Goddard http://1.usa.gov/1WtTHSr

References: https://twitter.com/EricHolthaus/status/632201801022877696 http://bit.ly/1Ko1Mip http://bit.ly/1Nj49rY

Dalmatian Mountain

This pattern of black and white was created by a combination of ash from Iceland’s 2010 Eyjafjallajökull eruption, snow on a nearby slope that survived until the middle of summer, dark exposed volcanic rock, and occasional patches of moss. The ash was sculpted into certain areas by the blowing winds as it fell – the same winds carried much of the eruption’s ash southeast towards Europe, disrupting air travel across the continent.

-JBB

Image credit: http://imaggeo.egu.eu/view/1870/