While Joe Romm, Bill McKibben, and others follow the fear card script to do everything and anything they can to link severe weather to global warming, they are clearly fighting a losing battle for public opinion on the issue. Now, even Andy Revkin at the New York Times doesn’t believe it anymore when it comes to tornadoes.*
He writes:
You can’t exclude climate change, but there’s simply no evidence through a half century of tornado history in the United States of a connection to warming.
Of course one of the strongest pieces of evidence has to do with the trend in the frequency of strong tornadoes, as shown in this somewhat dated graph from NCDC:
I’m looking forward to NCDC updating this data and graph. Obviously, there will be a new spike in 2011 rivaling 1974. But clearly, even with improved detection technology, the trend is down.
But this graph only goes back to 1950, and of course if we presented climate data only back that far, critics like the nefarious “Tamino” aka Grant Foster would have a cherry flavored cow, which is the typical M.O. for him. NCDC of course gets a pass.
Fortunately, I have some new tornado data to present that goes back further.
These two graphs below, courtesy of Dr. Indur Goklany, go back to 1900 and show the trend in death rates yearly, and by decade, since 1900:
Clearly death rates per million are down, which is testament to the improved warning technology, plus the skills and dedication of the National Weather Service and volunteer storm spotters at getting “eyes on” tornadoes to provide advance warning.
*UPDATE: Andrew Revkin writes in via email with this comment, which I am happy to reprint at his request – Anthony
You’ve cast my concerns about overstated discussions of tornadoes in the context of climate change as if this is new.
You must have missed my 2008 piece, including this section:
http://dotearth.blogs.nytimes.com/2008/02/07/climate-roundup-tornadoes-coral-drought/
Here is a copy of a post I made on Revkins website in response to his Tornado piece
Here is an excerpt from a Thirty Year Climate Forecast posted on my blog
climatesense-norpag.blogspot.com nearly one year ago which explains and anticipates the recent outbreak of Tornadoes.- the key item is the more meridional Jet Stream path on our cooling world in which the rising temperature trend peaked in 2003 and which has been cooling since then.
“Of particular note in climate forecasting is the negative phase of the PDO which began perhaps five years ago and may well last for another 25years. This suggests that La Ninas will be more frequent than El Ninos during this time span. A general earth cooling is thus more likely as was the case from 1940 to 1970 when similar conditions prevailed. Concurrent changes in the Arctic Oscillation suggest a pattern of meridional atmospheric flow will be more common than the more latitudinal flows of warmer periods.
Policymakers may wish to note the following possible effects on earth’s climate for the next 20 – 30 years. A cooler world with lower SSTs usually means a dryer world. Thus droughts will be more likely in for example east Africa with possible monsoon failures in India. In California the PDO will mean less rainfall with more forest fires in the south. However in the Cascades and Northern Sierras snowpack could increase since more of the rain could occur as snow. Northern Hemisphere growing seasons will be shorter with occasional early and late frosts and drought in the US corn belt and in Asia repeats of the harsh Mongolian and Chinese winters of 2009 – 10 . In Europe cold snowy winters and cool cloudy summers will be more frequent
There will be a steeper temperature gradient from the tropics to the poles so that violent thunderstorms with associated flooding and tornadoes will be more frequent in the USA, At the same time the jet stream will swing more sharply North – South thus local weather in the Northern hemisphere in particular will be generally more variable with occasional more northerly heat waves and more southerly unusually cold snaps. In the USA hurricanes may strike the east coast with greater frequency in summer and storm related blizzards more common in winter.”
In all modesty, although I say so myself, the forecast looks pretty good so far!!
“Policymakers may wish to note the following possible effects on earth’s climate for the next 20 – 30 years. A cooler world with lower SSTs usually means a dryer world. Thus droughts will be more likely in for example east Africa with possible monsoon failures in India. In California the PDO will mean less rainfall with more forest fires in the south.”
Norman, I suppose Rivkin posted this prediction mainly assuming that less water vapor would be available due to generally cool temps. However, with a negative PDO, a number of things occur. The temperature differential between the equator and the poles increase. North Pacific storms become more frequent, and a general strenghtening of the Icelandic Low occurs. The NAO will also show an increase in the negative phase due to increase baroclinicity between the poles and the equator. For North America, this means more precip, more snow, and more severe thunderstorms.
For the subtropics, there may indeed be more droughts. But I don’t think there is enough daya out there that describes definite trends in the Walker and Hadley Cells in relation to the PDO. We do know that Austrailia suffers through heavy precip events during La Ninas. Much of East Africa is dependent upon changes in the Walker Cell (as is India). During El Ninos, India and East Afric can suffer through droughts (which also affects the Nile Delta). La Nina events would esseintially disrupt these droughts.
JP – I think you misunderstood the post somewhat.The prediction was mine not Revkins.
The specific response in any particular area to a generally cooling world would be highly variable in time and space and requires a really detailed analysis of the the interaction of all the various global pressure system at any particular time and for any particular place. The forecasts I made were meant to be very general – really only suggesting the sort of thing we may expect.You would need a very knowledgeable meteorologist like d’Aleo or Joe Bastardi to work out the details.
One further note- to those blaming the tornadoes on a warm GOM check the current situation at http://weather.unisys.com/surface/sst_anom.gif
The northern Gulf is up to 2degrees cooler than average.
Lets compare the two, big destructive storm types Hurricanes and Tornadoes. Hurricanes are different, they are affected by several regional and global weather phenomena. El Niño/La Niña, winds across the Sahara desert, water temperatures, etc. Scientists know approximately how many Hurricanes will happen in a year by performing metrics on these natural phenomena.
The conditions that create tornadoes do not offer the same opportunity for long-term prediction. We know that sort of regional weather phenomena cause tornadoes. Scientists occasionally get a week before a burst of tornadoes in a region. Because the conditions that create tornadoes are on such a small scale (compared to the weather of the world at large), we have no science right now that connects global climate patterns to tornado generation.
So, attempting to connect Tornado occurrence to global climate is foolish.