Kevin Trenberth and Jennifer Francis on Climate, Ice, and Weather Whiplash

Latest piece for the Yale Forum on Climate Change and the Media.

Last month I covered the emerging science linking arctic ice loss to changes in the jetstream, and the new normal “Weather Whiplash” we are seeing in the Northern Hemisphere the last several years.

Although nearly all climate scientists are in agreement on the general outlines of climate change and greenhouse gas effects, there are still, and will continue to be, areas of the science that are not yet “pound on the table we’re done” as Richard Alley likes to say.  Dr. Jennifer Francis of Rutgers has been making a persuasive case for the last year that polar amplification, and the loss of arctic ice and snow cover, are starting to have dramatic effects on global weather through the jet stream. See that video below if you have not already.

Not everyone is in complete agreement. Dr. Kevin Trenberth is a highly respected senior researcher at the US National Center for Atmospheric Research in Colorado. He reasons that because heat flows are so much greater in the tropics, that we should continue to look there for answers to the puzzle.  I talked to both experts last month, and boiled down the discussion here.

I’ll be posting the complete interviews at a later time for serious wonks, but maybe not till I get back from Greenland.

See the first “Whiplash” video below.

10 thoughts on “Kevin Trenberth and Jennifer Francis on Climate, Ice, and Weather Whiplash”


  1. The claim that the melting – a changing Arctic ice extent – mainly responsible for the change in the jet stream, is based on a very low degree of correlation (virtually none – not statistically significant) between the two parameters.
    For example, ice extent for the month of May (http://nsidc.org/arcticseaicenews/files/2013/06/Figure3-350×261.png_). We see here a small Arctic ice coverage (less than now) since 2003. Meanwhile, responsible for the formation of such harsh winters in Europe atmospheric pressure system (his high frequency) has only existed since 2008. Previously, there was a predominance of mild winters – although small
    ice extent (less – for May – than it is today).
    Significant changes in the jet stream occurred after 2008 and are strongly correlated with extremely low solar minimum and the current very weak solar cycle 24. In addition, at that time strongly indicated the negative phase of the PDO, AMO entered a positive phase, there were essential – the natural changes in the index and the oscillation of Arctic, oscillations associated with the Arctic. Nor can we ignore the changes in the LTC.
    The great merit J.F. is finding a strong jet stream affect the climate (and weather) a regional. In light of the above, however, claim that global warming – melting of Arctic sea ice has a decisive influence on the jet stream, is pseudoscientific nonsense (I’m so sorry but otherwise it can not be called).

    On a side note (for those who are “fascinated” by a change in arctic ice extent): 28 May in the Arctic came to 11 thousand. km2, which at this time of year is usually is no longer happens. It was the fifth month in the ice growth in the Arctic. This year in May added more than 200 thousand. km2. Last year, there were only two days of growth, which more total increase was only 10 thousand. km2. At the end of May was 188 thousand. km2 of ice more than last year.


  2. Does the stuff from “semczyszakarkadiusz” have anything behind it in the published science? It’s got the buzzwords correlation and significance but no cite to a source for the statistical claims made about various correlations.

    The post seems to assume we’re already at a low solar maximum.

    “Reality is more complicated. Astronomers have been counting sunspots for centuries, and they have seen that the solar cycle is not perfectly regular. The back-and-forth swing in sunspot counts can take anywhere from 10 to 13 years to complete. Also, the amplitude of the cycle varies; some solar maxima are very weak, others very strong.” http://earthobservatory.nasa.gov/IOTD/view.php?id=80572

    (And what’s “LTC?”)


  3. Climate Deniers always claim that no one can publish against the status quo or show finding that one of the leaders in their field could be wrong. But reality trumps Climate Deniers.

    Forthcoming issue of Geophysical Research Letters (link below), challenges the findings of previous studies that showed a slowdown in the speed and changes in the shape of the jet stream (Jennifer Francis). This is how science works.

    http://barnes.atmos.colostate.edu/FILES/MANUSCRIPTS/Barnes_2013_GRL_wfigs_wsupp.pdf

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