The last three years are the hottest ever recorded and the rate of global warming during this period is “exceptional”, warned Thursday the United Nations.
“It is now confirmed that the years 2015, 2016 and 2017, which are clearly in line with the long-term warming trend caused by increasing atmospheric concentrations of greenhouse gases, are the three hottest years ever recorded,” said the World Meteorological Organization (WMO), a UN specialized agency.
Under the effect of a powerful Nino – a phenomenon known to push up the average global temperature that comes every three to seven years – 2016 is at the top of the list with 1.2 ° C more than in pre-industrial times (the UN uses the 1880-1900 period as a reference for conditions prevailing in the pre-industrial era), while 2017 wins the record for the hottest year without Nino.
“These new temperature data show that the world is warming up fast,” said Dave Reay, a professor at Edinburgh University, reacting to the report.
According to the latest data, WMO found that the average global temperature in 2017 and 2015 was about 1.1 ° C above pre-industrial levels.
Experts say that it is almost impossible to separate these two years because the difference in temperature is less than one-hundredth of a degree, less than the statistical margin of error.
“It is much more important to examine the long-term evolution of the temperature, which shows an upward trend, than to make a ranking between different years,” said however the Secretary General of WMO, Finland’s Petteri Taalas.
“17 of the warmest 18 years are in the 21st century, and the rate of warming over the past three years has been exceptional, with a particularly strong and lasting impact on the Arctic as well as sea and weather patterns in other parts of the world,” he said.
The United Nations uses data from, among others, the US National Oceanic and Atmospheric Administration (NOAA), the United States Aeronautics and Space Administration (NASA), the British Meteorological Service’s Hadley Center, the European Center for Medium-rare Weather Forecasts (ECMWF) and the Japan Meteorological Service.
According to statistics, the average temperature in 2017 has exceeded by approximately 0.46 ° C the normal calculated for the years 1981 to 2010.
“The record temperature should draw the attention of world leaders, including President Trump, to the magnitude and urgency of the risks that climate change poses to the world’s rich and poor,” said Bob. Ward from the London Grantham Research Institute on Climate Change.
Donald Trump, skeptical about the reality of climate change, has withdrawn the United States from the Paris climate agreement saying it would destroy industrial jobs.
With the agreement of Paris in 2015, the international community has pledged to contain warming “well below” 2 ° C.
“With the current statistical trend of global warming, we can already predict that by 2060, 2070, we will be able to reach this threshold,” Omar Baddour, scientific coordinator at WMO, told the media in Geneva.
And “if the warming continues to be accelerated by more emissions of greenhouse gases, we can also reach this threshold probably well before that date,” he warned.
Rising temperatures are only part of climate change, the UN notes, noting that the heat of 2017 has been accompanied by extreme weather conditions around the world.
“This is the most expensive year for the United States of America in terms of weather and climate disasters, while in other countries, tropical cyclones, droughts and floods have slowed down economic growth,” said Taalas.