The US National Oceanic and Atmospheric Administration (NOAA) has announced that July 2015 was the hottest month on record, and 2015 is shaping up to be the hottest year. Outlined in its monthly global climate report, the NOAA's analysis has found that in July, the combined average temperature over global land and ocean surfaces was 16.61 degrees Celsius, which is higher than it's ever been since we started keeping records in 1880.
This is in spite of the fact that some places around the world, such as Australia, experienced colder than average temperatures that month. "There are some places across the globe that were cooler than average during July," NOAA climate scientist Jake Crouch told the ABC. "Even though it might be colder than average in our backyard, [that] does not necessarily reflect of the rest of the globe."
When the NOAA compared the global average temperartures for the first seven months of 2015, they found they were 0.85 degrees above the 20th century average, which overtakes the previous record set in 2010 by 0.09 degrees. In the coming months, we'll know if 2015 will overtake 2014 as the hottest year on record, but right now, it's looking very likely. "I would say [we're] 99 percent certain that it’s going to be the warmest year on record," NOAA climate scientist Jessica Blunden said during a press teleconference yesterday.
The oceans have certainly felt the recent increase in temperature, with the global average hitting 16.4 degrees. According to The Sydney Morning Herald, the 0.75-degree increase from the recent average was not only the largest on record for July, but for any month on record.
So what's causing such a historic rise in temperature? Crouch told the ABC that two main factors are at play: a long-term warming trend across the globe, plus the formation of El Nino in the equatorial Pacific region. The current iteration of El Nino has already been confirmed as one of the strongest on record, and it's predicted to linger well into 2016.
The reason an El Nino event can actively increase global average temperatures, James Dyke from the University of Southampton in the UK explains, is because it causes sea surface temperatures in the central and eastern equatorial regions of the Pacific to rise significantly, which slows down the trade winds that blow across the South Pacific to the west. "One result of this is that the warm waters that were previously concentrated into an area of the south west Pacific towards Australasia spread out eastwards across the whole ocean," says Dyke. "This delivers a pulse of heat from the seas to the atmosphere."
The NOAA report comes three months before the world's leaders will meet in Paris for the 2015 United Nations Climate Change Conference, the objective of which will be to formulate a legally binding and universal agreement on the future of Earth's climate, to which all the nations of the world will be held accountable. We can't wait to hear the results.