Social media posts declare report snow cowl within the northern hemisphere in November 2022 is proof in opposition to local weather change. That is false; specialists say a single month’s measurement doesn’t disprove the general international warming pattern, and information present snow extent varies and that cowl has decreased.
Throughout the United Nations (UN) COP27 local weather summit in Egypt, “November’s snowfall throughout the Northern Hemisphere was operating at charges exceeding a half-a-century common,” says a December 3, 2022 article from Zero Hedge, a conspiratorial web site that has beforehand printed misinformation. “Most mainstream media retailers missed this information as a result of it’s an inconvenient reality for the local weather change narrative they’re pushing.”
The declare was republished by blogs and shared in posts on Facebook and Twitter, together with in French. An article tweeted by Patrick Moore, a outstanding local weather change denier who has made false claims about his hyperlinks to Greenpeace, was shared 1000’s of occasions on Twitter.
Screenshot of a Fb publish taken December 6, 2022
Screenshot of a tweet taken December 6, 2022
The articles cite graphs and maps with data from the US Nationwide Oceanographic and Atmospheric Administration (NOAA) and the Global Snow Lab at Rutgers College within the state of New Jersey. The numbers point out northern hemisphere snow extent reached about 41 million sq. kilometers (16 million sq. miles) in November, a 56-year excessive.
However specialists say the info don’t replicate the pattern for common snow extent.
“You may’t hyperlink one map and even one month to international local weather change. One must look over years if not many years to get a way of the place and why the extent of snow cowl could or might not be altering,” stated climatologist David Robinson, director of the Rutgers World Snow Lab, in an e mail on November 28.
Snow cowl decreased
Newer information present snow extent within the northern hemisphere has once more dropped beneath the report degree.
“Mid-November snow cowl extent was properly above regular throughout northern hemisphere lands. Nevertheless, as November ends, that’s not the case,” Robinson stated. “As an example, there was main melting of the sooner snowpack throughout a lot of North America such that extent for late November has fallen beneath regular.”
The Rutgers World Snow Lab graph cited within the Zero Hedge article compares month-to-month readings for snow cowl within the northern hemisphere to the utmost and minimal values recorded since information started in 1967, in addition to the common.
The graph exhibits snow cowl (purple line) surpassed the report (blue line) in mid-November. An up to date graph printed by the World Meteorological Group (WMO) for the week ending November 28 confirmed that month’s studying had dipped beneath the report once more.
Screenshot of the WMO’s World Cryosphere Watch web page displaying a NOAA/Rutgers graph of northern snow extent
Screenshot of a graph from the WMO’s World Cryosphere Watch web page displaying snow extent dipping in late November 2022
A 2019 study examined six datasets stretching again to 1981 and located reducing tendencies for each the extent and mass of snow within the northern hemisphere (NH).
The research famous “sturdy damaging NH snow extent tendencies in early winter and spring and constantly sturdy, damaging snow mass tendencies from November by means of Could.” It additionally stated “snow mass tendencies are damaging by means of your complete snow season,” together with in autumn.
Cherry-picking information to refute the pattern of worldwide warming is a typical tactic of local weather change deniers. AFP has debunked examples in a number of earlier reality checks.
The chart beneath from the Rutgers World Snow Lab exhibits in crimson a variety of snow-free areas the place there often is a few on December 5. They seem to exceed areas with snow the place there’s often none, proven in blue.
Screenshot of a map from the Rutgers World Snow Lab displaying northern hemisphere snow anomalies on December 5, 2022
“Snow cowl may be very variable from one yr to the following. A really snowy yr doesn’t imply that the heating of the local weather has stopped,” Marie Dumont, director of France’s nationwide Snow Research Centre, advised AFP on November 29. “You may very properly have a really snowy yr in a context of a warming local weather.”
She added that “on common, in keeping with the tendencies noticed over a number of many years, there’s a median lower in snow cowl” — however that “doesn’t imply there’s a lower yearly.”
Scientists agree that carbon emissions from people burning fossil fuels are inflicting local weather change, heating the planet and elevating the risk of disasters corresponding to heatwaves, floods and droughts.
The left facet of a chart from that report exhibits temperatures rising sharply over the previous 150 years. On the correct facet of the chart, a blue line exhibits how a lot decrease international temperatures can be with out people releasing greenhouse gases.
Screenshot of a chart displaying human-made emissions heat the planet from the IPCC’s Sixth Evaluation Report
In its 2019 report on the oceans and cryosphere — frozen areas — the IPCC stated: “During the last many years, international warming has led to widespread shrinking of the cryosphere, with mass loss from ice sheets and glaciers … reductions in snow cowl … and Arctic sea ice extent and thickness … and elevated permafrost temperature.”
Produced by tons of of scientists in additional than 60 international locations, the IPCC’s stories are probably the most complete supply of scientific data on the local weather.
AFP has fact-checked different false and deceptive claims about local weather change right here.