Will 2016 be the hottest year on record?

In the first six months of 2016, temperatures have been record hot – and it's not just because of El Niño. 

First Look

The earth is breaking records, and not in an Olympic-victory kind of way. Scientists at the National Oceanic and Atmospheric Administration (NOAA) said Tuesday that June was the 14th straight month with a record highest average temperature since the Earth's temperature started being recorded back in 1880.

That means that the last month that didn't break records for hottest average temperature was April 2015.

And experts say that 2016 will be the hottest year on record – a feat already accomplished both in 2014 and 2015.

In addition to record-breaking heat, the first months of 2016 have also found Earth facing other notable bellwethers, from vanishing ice levels to crossing a temperature zone that just last year was marked as a threshold to avoid.

One of the stipulations of the December 2015 Paris Accord environmental pact was that the world's nations would "pursue efforts" to limit Earth's temperature increase to 1.5 degrees Celsius above pre-industrial levels, by reducing emissions and investing in carbon sinks and cleaner energy.

Two degrees Celsius was then designated as the collective target that the nearly 200 nations who attended the talks agreed that the Earth's temperature must be held below. Such a rise in average temperature would still include detrimental effects, such as severe weather and rising oceans, but could help the Earth avoid true catastrophe, scientists said.

But NASA chief climate scientist Gavin Schmidt said the first six months of 2016 were not just the warmest on record, but have been about 2.7 degrees F. – which equates to the symbolic 1.5 degrees Celsius mark – warmer than pre-industrial times.

And compared even to last year's records, "2016 has really has blown that out of the water," Dr. Schmidt told NPR.

The overall sustained, elevating temperatures over decades, coupled with this year's heat, has had observable effects on Arctic ice levels.

"We've had the lowest sea ice extent average over the first six months by a fair amount in our satellite record going back to 1979," says Walt Meier, a NASA sea ice scientist. Apart from contributing to rising sea levels, the disappearance of ice has a strong detrimental effect on the habitats of Arctic animals.

And for humans, 2016's high average heat has also resulted in excessive heat warnings, like the ones issued by NOAA for much of the US this week.

Scientists acknowledge that while the general warming trend is undeniable, this year's heat records are not all because of climate change – high temperatures in the first half of 2016 have been exacerbated by the El Niño weather phenomenon, a pattern that sends the Pacific's warm air and water toward the east.

Schmidt estimates that about 40 percent of the reason 2016 has been hotter than 2015 is due to El Niño, and says that 2017 will likely be a bit cooler than 2016. This means that year's average temperatures may back off of the 1.5 degree Celsius threshold, which scientists typically measure as part of an average, not just one year.

However, El Niño ended a couple of months ago and 2016 is still projected to end up as the hottest year on record. So when it comes to the 1.5 degree Celsius threshold, Schmidt see this year as an indicator of where the planet stands:

"It's fair to say we are dancing with those lower targets," he said.

Material from the Associated Press was used in this report.