NOAA reports “April 2011: historic U.S. extremes in rains, floods, tornadoes, and fires”
NOAA’s National Climatic Data Center: “April was a month of historic climate extremes across much of the United States, including: record breaking precipitation that resulted in historic flooding; recurrent violent weather systems that broke records for tornado and severe weather outbreaks; and wildfire activity that scorched more than twice the area of any April this century.”
The NCDC report for April reads like something out of a book titled … oh, I don’t know, Hell and High Water.
Multiple scientific studies find that indeed the weather has become more extreme, as expected, and that it is extremely likely that humans are a contributing cause (see “Two seminal Nature papers join growing body of evidence that human emissions fuel extreme weather, flooding that harm humans and the environment” and links therein).
Equally important, human-caused climate change is exacerbating the extreme events we would normally experience — by making deluges more intense (because of the extra water vapor in the atmosphere) and by making droughts hotter.
“All extreme weather events are now subject to human influence,” said Dr. Peter Gleick, a climate & water scientist and president of the Pacific Institute, at a Capitol Hill briefing on Monday organized by the American Meteorological Society. “We are loading the dice and painting higher numbers on them.”
As the reinsurer Munich Re put in in September, “The only plausible explanation for the rise in weather-related catastrophes is climate change”
The staggering reality of the Mississippi flooding has consumed most of the extreme weather news, otherwise the news stories would be all about how a “record breaking 1.79 million acres burned across the country during the month”:
Back in mid-april I reported how an “unprecedented drought” is driving “never-before-seen wildfire situation in Texas.” Now meteorologist Dr. Jeff Masters reports today at Weather Underground that the “Great Texas drought of 2011 intensifies“:
April 2011 was the 5th driest and 5th hottest April in Texas history, going back 117 years. Exceptionally dry conditions have parched the soil and vegetation in Texas, which recorded precipitation of just 1.68 inches (43 mm,) on average, since February 1st. This is easily its driest February-April period on record for the state, nearly an inch less than the previous record (2.56 inches or 65 mm, Feb – Apr 1996.) The six-month period November 2010 – April 2011 was the 2nd driest such period on record. Based on the U.S. Drought Monitor, 94 percent of Texas is in severe to exceptional drought.
As a result of the great drought, an all-time April record of 1.79 million acres of land burned last month in the U.S., mostly in Texas. Much of the fuel for the fires came from dried underbrush and grasses which experienced ideal growing conditions during the summer of 2010, when there was abundant rain across the region. Nation-wide, the year-to-date period, January – April, has the greatest acreage burned in history, according to the National Interagency Fire Center.
At the same time, Capitol Climate reports Record Heat in Kansas, Missouri, Oklahoma; Earliest 100° at Wichita, “The high of 100° at Wichita not only smashed the 116-year-old record for the date by 5°, but it was the earliest 100° ever recorded there.”
The UK Guardian notes in its piece, “Memphis on flood alert as Mississippi waters hit record peak, ” that the heavy snows plus “an extremely wet April - with 600% more rain than normal in some southern states – have turned 2011 into a season of floods along the Mississippi’s 2,320-mile route.”
NCDC reports that it was the wettest April on record in six number of states that drain into the Mississippi:
Masters notes, “Some areas along the Ohio River Valley received up to 20 inches of rain during the month, which is nearly half their normal annual precipitation.” Why did this happen?
Exceptionally warm air flowing from the Gulf of Mexico, which had near record-warm sea surface temperatures, gave Florida, Louisiana, and Texas top-ten warmest Aprils.
Again, Dr. Kevin Trenberth, head of the Climate Analysis Section of the National Center for Atmospheric Research, explained here both the connection between global warming and deluges — and how this has been underplayed by many scientists and the media:
I find it systematically tends to get underplayed and it often gets underplayed by my fellow scientists. Because one of the opening statements, which I’m sure you’ve probably heard is “Well you can’t attribute a single event to climate change.” But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.
Karl told the NY Times last year, “It’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”
Tom Karl, now director of NCDC, emailed me last week:
Joe, what we can say with confidence is that heavy and extreme precipitation events often associated with thunderstorms and convection are increasing and have been linked to human induced changes in atmospheric composition.
As for tornadoes, April smashed a number of all-time records. Masters notes, “The largest tornado outbreak and greatest one-day total for tornadoes in history occurred during the historic April 25 – 28, 2011 tornado outbreak.” NOAA released all the details yesterday here.
The attribution of extreme tornado events to global warming is tougher to make than for many other extreme events, as I discussed in detail here: “Tornadoes, extreme weather, and climate change.” But just because attribution is difficult doesn’t mean that the subject of global warming should be avoided entirely when talking about tornadoes. Former “adamant skeptic” about human-caused warming, Stu Ostro, who is a Weather Channel Senior Meteorologist, put it well in “The Katrina of tornado outbreaks“: The atmosphere is extraordinarily complex, and ultimately what’s happened the past month is probably a combination of influences, including La Nina, other natural variability, and anthropogenic global warming.”
Equally important, when discussing extreme weather and climate, tornadoes should not be conflated with the other extreme weather events for which the connection is considerably more straightforward and better documented.
And yes, it is always important to repeat that what we are seeing along the Mississippi is also a result of bad planning by us. The Guardian quotes climate and water expert Gleick:
Since 1993, we have seen huge numbers of new homes and business built on the flood plain despite recommendations never to do that again,” said Gleick. “I think what we are seeing along the Mississippi is all of those things: climate change, bad planning, bad development and inappropriate levees.“
Finally, it is worth simply listing all of the climate extremes set last month, as NCDC has done:
“April is the cruelest month” begins T.S. Eliot’s classic, “The Waste Land.”
We’ve only warmed about a degree Fahrenheit in the past half-century. We are on track to warm nearly 10 times that this century (see M.I.T. doubles its 2095 warming projection to 10°F “” with 866 ppm and Arctic warming of 20°F). That means in term of cruel months, we ain’t seen nothing yet!
- Weather Channel expert Stu Ostro discussed Georgia’s record-smashing global-warming-type deluge: “Nevertheless, there’s a straightforward connection in the way the changing climate “set the table” for what happened this September in Atlanta and elsewhere. It behooves us to understand not only theoretical expected increases in heavy precipitation (via relatively slow/linear changes in temperatures, evaporation, and atmospheric moisture) but also how changing circulation patterns are already squeezing out that moisture in extreme doses and affecting weather in other ways.”
- We had Tennessee’s 1000-year deluge aka Nashville’s ‘Katrina’.
- High Water: Coastal North Carolina’s second 500-year rainfall in 11 years
- NOAA: Climate change “largely irreversible for 1000 years,” with permanent Dust Bowls in Southwest and around the globe.
- Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year “” and that isn’t the worst case, it’s business as usual!
- U.S. southwest could see a 60-year drought like that of 12th century “” only hotter “” this century
- Study: Global warming is driving increased frequency of extreme wet or dry summer weather in southeast, so droughts and deluges are likely to get worse