2017 revealed as warmest non-El Nino year

The World Meteorological Organisation has announced that 2017 was, globally, the joint second warmest year on record, continuing the dramatic rise in global temperatures in recent years.

In a timeline of observational data, which stretches back to 1880, WMO’s statistics showed that 2017 tied with 2015, with these years only slightly less warm than 2016.

Needless to say, the period from 2015 to 2017 is far and away the warmest such period within the timeline.

2017 is also the warmest year without an El Nino. This natural event, which manifests itself as a warming of the surface waters of the eastern Pacific, is thought to account for a global rise in temperature of 0.2C.

That 2017 was a mere 0.1C below 2016 shows just how warm the last 12 months have been. This is especially so when there were hints of a cooling La Nina developing at the end of 2017.

Other weather agencies have also issued similar results with NASA, NOAA, UK Met Office and the Japan Meteorological Agency all declaring 2017 the second or third warmest on record. Calculations vary according to the degree of inclusion of the polar regions, and whether sea temperatures are included.

As well as horizontal warming, NASA has confirmed similar findings for the warming through the atmosphere to a height of eight kilometres.

Higher air and sea temperatures have, in turn, had a major impact on ice coverage, with 2017 seeing the second-lowest coverage on record.

The 21^st century accounts for 17 of the 18 warmest years on record. Only 1998, a year with a very strong El Nino, manages to break the monopoly. Despite commitments at Conventions in Paris and Bonn, to limit global warming to no more than 1.5C above pre-industrial levels, we are now 1.1C above pre-industrial levels.

Virtually all this warming is attributable to human activity, primarily the burning of fossil fuels. As a result of this process, carbon dioxide levels have risen from 280 parts per million (ppm) in pre-industrial times, to 407 ppm today. Carbon dioxide is the most significant gas adding to the natural greenhouse effect.

Next week sees the start of the World Economic Forum in Davos, Switzerland, which US president, and climate change denier, Donald Trump will attend.

As Bob Ward, policy director of the Grantham Research Institute on Climate Change said, “The record temperature should focus the minds of world leaders, including President Trump, on the scale and urgency of the risks that people, rich and poor, face around the world from climate change.”