I’ve been able to obtain some highlights and findings in advance of release of the full report which is expected later today. It seems the only facet of severe weather they aren’t trying to link to climate change is tornadoes and lightning. They say:
The full report of the National Climate Assessment provides an in-depth look at climate change impacts on the U.S. It details the multitude of ways climate change is already affecting and will increasingly affect the lives of Americans.
Explore how climate change affects you and your family.
…
Winter storms have increased in frequency and intensity since the 1950s, and their tracks have shifted northward. Other trends in severe storms, including tornadoes, hail, and thunderstorms, are still uncertain.
So basically, they are trying to make people afraid of the more mundane weather, but stop short on tornadoes and thunderstorms, because they know they’ll be called out on it. Hurricanes are something they still embrace as being climate related, even though we are onto the longest major hurricane drought in U.S. history, expected to be 3,142 days when hurricane season starts on June 1st, 2014.
I’m providing the section on severe weather now without further comment.
Introduction
As the world has warmed, that warming has triggered many other changes to the Earth’s climate. Changes in extreme weather and climate events, such as heat waves and droughts, are the primary way that most people experience climate change. Human-induced climate change has already increased the number and strength of some of these extreme events. Over the last 50 years, much of the U.S. has seen increases in prolonged periods of excessively high temperatures, heavy downpours, and in some regions, severe floods and droughts.
![f2-coast-to-coast-hi[1]](http://wattsupwiththat.files.wordpress.com/2014/05/f2-coast-to-coast-hi1.jpg?quality=83)
Heat waves are periods of abnormally hot weather lasting days to weeks. The number of heat waves has been increasing in recent years. This trend has continued in 2011 and 2012, with the number of intense heat waves being almost triple the long-term average. The recent heat waves and droughts in Texas (2011) and the Midwest (2012) set records for highest monthly average temperatures. Analyses show that human-induced climate change has generally increased the probability of heat waves., And prolonged (multi-month) extreme heat has been unprecedented since the start of reliable instrumental records in 1895.
Drought
![f2-texas-scatter-hi[1]](http://wattsupwiththat.files.wordpress.com/2014/05/f2-texas-scatter-hi1.jpg?quality=83)
Higher temperatures lead to increased rates of evaporation, including more loss of moisture through plant leaves. Even in areas where precipitation does not decrease, these increases in surface evaporation and loss of water from plants lead to more rapid drying of soils if the effects of higher temperatures are not offset by other changes (such as reduced wind speed or increased humidity). As soil dries out, a larger proportion of the incoming heat from the sun goes into heating the soil and adjacent air rather than evaporating its moisture, resulting in hotter summers under drier climatic conditions.
An example of recent drought occurred in 2011, when many locations in Texas and Oklahoma experienced more than 100 days over 100°F. Both states set new records for the hottest summer since record keeping began in 1895. Rates of water loss, due in part to evaporation, were double the long-term average. The heat and drought depleted water resources and contributed to more than $10 billion in direct losses to agriculture alone.
Heavy Downpours
Heavy downpours are increasing nationally, especially over the last three to five decades. The heaviest rainfall events have become heavier and more frequent, and the amount of rain falling on the heaviest rain days has also increased. Since 1991, the amount of rain falling in very heavy precipitation events has been significantly above average. This increase has been greatest in the Northeast, Midwest, and upper Great Plains – more than 30% above the 1901-1960 average. There has also been an increase in flooding events in the Midwest and Northeast, where the largest increases in heavy rain amounts have occurred.
Observed U.S. Trends in Heavy Precipitation
![CS_extreme-precip-index_13263_V9[1]](http://wattsupwiththat.files.wordpress.com/2014/05/cs_extreme-precip-index_13263_v91.png?quality=75)
The mechanism driving these changes is well understood. Warmer air can contain more water vapor than cooler air. Global analyses show that the amount of water vapor in the atmosphere has in fact increased due to human-caused warming.,,, This extra moisture is available to storm systems, resulting in heavier rainfalls. Climate change also alters characteristics of the atmosphere that affect weather patterns and storms.
Floods
Flooding may intensify in many U.S. regions, even in areas where total precipitation is projected to decline. A flood is defined as any high flow, overflow, or inundation by water that causes or threatens damage. Floods are caused or amplified by both weather- and human-related factors. Major weather factors include heavy or prolonged precipitation, snowmelt, thunderstorms, storm surges from hurricanes, and ice or debris jams. Human factors include structural failures of dams and levees, altered drainage, and land-cover alterations (such as pavement).
Major Flood Types
All flood types are affected by climate-related factors, some more than others.
Flash floods occur in small and steep watersheds and waterways and can be caused by short-duration intense precipitation, dam or levee failure, or collapse of debris and ice jams. Most flood-related deaths in the U.S. are associated with flash floods.
Urban flooding can be caused by short-duration very heavy precipitation. Urbanization creates large areas of impervious surfaces (such as roads, pavement, parking lots, and buildings) that increased immediate runoff, and heavy downpours can exceed the capacity of storm drains and cause urban flooding.
Flash floods and urban flooding are directly linked to heavy precipitation and are expected to increase as a result of increases in heavy precipitation events.
River flooding occurs when surface water drained from a watershed into a stream or a river exceeds channel capacity, overflows the banks, and inundates adjacent low lying areas. Riverine flooding depends on precipitation as well as many other factors, such as existing soil moisture conditions and snowmelt.
Coastal flooding is predominantly caused by storm surges that accompany hurricanes and other storms that push large seawater domes toward the shore. Storm surge can cause deaths, widespread infrastructure damage, and severe beach erosion. Storm-related rainfall can also cause inland flooding and is responsible for more than half of the deaths associated with tropical storms. Climate change affects coastal flooding through sea level rise and storm surge, and increases in heavy rainfall during storms.
Increasingly, humanity is also adding to weather-related factors, as human-induced warming increases heavy downpours, causes more extensive storm surges due to sea level rise, and leads to more rapid spring snowmelt.
![f2-trends-flood-hi[1]](http://wattsupwiththat.files.wordpress.com/2014/05/f2-trends-flood-hi1.jpg?quality=83)
Worldwide, from 1980 to 2009, floods caused more than 500,000 deaths and affected more than 2.8 billion people. In the United States, floods caused 4,586 deaths from 1959 to 2005 while property and crop damage averaged nearly 8 billion dollars per year (in 2011 dollars) over 1981 through 2011. The risks from future floods are significant, given expanded development in coastal areas and floodplains, unabated urbanization, land-use changes, and human-induced climate change.
Hurricanes
There has been a substantial increase in most measures of Atlantic hurricane activity since the early 1980s, the period during which high quality satellite data are available.,, These include measures of intensity, frequency, and duration as well as the number of strongest (Category 4 and 5) storms. The recent increases in activity are linked, in part, to higher sea surface temperatures in the region that Atlantic hurricanes form in and move through. Numerous factors have been shown to influence these local sea surface temperatures, including natural variability, human-induced emissions of heat-trapping gases, and particulate pollution. Quantifying the relative contributions of natural and human-caused factors is an active focus of research.
Hurricane development, however, is influenced by more than just sea surface temperature. How hurricanes develop also depends on how the local atmosphere responds to changes in local sea surface temperatures, and this atmospheric response depends critically on the cause of the change., For example, the atmosphere responds differently when local sea surface temperatures increase due to a local decrease of particulate pollution that allows more sunlight through to warm the ocean, versus when sea surface temperatures increase more uniformly around the world due to increased amounts of human-caused heat-trapping gases.,,,
By late this century, models, on average, project an increase in the number of the strongest (Category 4 and 5) hurricanes. Models also project greater rainfall rates in hurricanes in a warmer climate, with increases of about 20% averaged near the center of hurricanes.
Change in Other Storms
Winter storms have increased in frequency and intensity since the 1950s, and their tracks have shifted northward over the United States., Other trends in severe storms, including the intensity and frequency of tornadoes, hail, and damaging thunderstorm winds, are uncertain and are being studied intensively. There has been a sizable upward trend in the number of storms causing large financial and other losses. However, there are societal contributions to this trend, such as increases in population and wealth.
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How do they define “heavy downpours”?
@Jimbo
“While the question of climate change “deserves lots of attention,” Buffett said in a “Squawk Box” interview, “It has no effect … [on] the prices we’re charging this year versus five years ago. And I don’t think it’ll have an effect on what we’re charging three years or five years from now.” He added, “That may change ten years from now.”……………
http://www.cnbc.com/id/101460458”
I assume what was left of was Warren’s conclusion “…because in ten years I’ll be dead and who knows what the idiots in charge at that point will do.”
Expect more floods in a warmer world. Of course dear.
ferdberple says:
May 6, 2014 at 7:17 am
Winter storms have increased in frequency and intensity since the 1950s,
================
No wonder they stopped calling it Global Warming.
Wouldn’t increasing winter storms be more likely a sign that the next Ice Age is approaching?
________________________
Here’s my best imitation of a voice from deep within the climate fearosphere:
“Global warming means more evaporation and warmer air holds more water, so it snows more.”
Expect moreless floods.
The whole extreme weather section is another version of “if you like your insurance you can keep your insurance” when the reality was 7 million cancellations.
Perhaps this obvious weather canard , like Obummercare and the Keystone pipeline punt, can be put to good use in November.
We must act now to save our Great Plains’ agriculture. You know it’s the right thing to do.
from above: “The mechanism driving these changes is well understood. Warmer air can contain more water vapor than cooler air. Global analyses show that the amount of water vapor in the atmosphere has in fact increased due to human-caused warming.”
James (@JGrizz0011) says:
Does anyone know where I can find confirmation if this is this true and to what degree?
V.Isaac and W.A. van Wijngaarden,2012: Surface Water Vapour Pressure and Temperature Trends in North America during 1948-2010. Journal of Climate 2012.
“The averages of the seasonal trends are .20C/decade and .07hPa/decade which correspond to a specific humidity increase of .04g/kg per decade and a relative humidity reduction of .5%/decade.
or see
Variations in annual global preicpitation (1979-2004) based on the Global Precipitation Climatology Project. Thomas Smith, Xungand Yin, Arnold Gruber, Geophysical Research Letters Vol 33, Issue 6, March 2006.
“(precipitation) trends have spatial variations both positive and negative values, with a global- average near zero.
Warmer air can contain more water vapor than cooler air. Global analyses show that the amount of water vapor in the atmosphere has in fact increased due to human-caused warming.”
Actual causation or correlation? So natural warming doesn’t cause increases in water vapor?
The “intelligentsia” in D.C. and in some institutes of “higher learning” will never doubt their fervent belief in climate change [by which they mean AGW] until there are mile high glaciers marching down Pennsylvania Ave. Even in that event they would probably just look at the icy evidence against AGW and say “Wuzzat?”
Does this nonsense never stop? [rhetorical]
An example of recent drought occurred in 2011, when many locations in Texas and Oklahoma experienced more than 100 days over 100°F. Both states set new records for the hottest summer since record keeping began in 1895.
Hmmm. Why 1895? A quick check of the station history file at
http://cdiac.ornl.gov/ftp/ndp070/history.txt
shows the following Texas stations with earlier records:
Alice 1892
Boerne 1876
Brenham 1885
Brownwood 1888
Clarksville 1870
Corpus Cristi 1887
Corsicana 1874
Crosbyton 1886
Dublin 1890
Eagle Pass 1849
El Paso 1877
Ft Stockton 1859
Gainsville 1889
Halletsville 1891
Haskel 1890
Lampasas 1888
Llano 1891
Luling 1882
Marshal 1892
Mexia 1888
Miami 1888
New Braunfels 1853
Pecos 1889
Plainview 1889
Quanah 1891
Rio Grande City 1849
San Antonio 1846
Snyder 1889
Temple 1882
Weatherford 1882
Would the claim to all time records stand, if the record extended back to the belligerent weather of the last half of the 19th century?
James (@JGrizz0011) says: May 6, 2014 at 7:04 am
“Global analyses show that the amount of water vapor in the atmosphere has in fact increased…”. Does anyone know where I can find confirmation if this is this true and to what degree? I was under the impression that that amount of water vapour in the atmosphere has not increased. Thanks.
Here is specific %: http://i61.tinypic.com/2wp16vt.jpg
Relative %: http://i48.tinypic.com/14mwa5y.jpg
” : http://i48.tinypic.com/2qlfnzn.jpg
Arguing about the validity of the report is pointless. For now all countries must begin changing from fossil fuels (which are running out anyway) to sustainable forms of energy. In addition, it would be useful if countries also developed ways in which flood waters, or more accurately, waters which could potentially be flood waters, are harnessed and stored for future use by local populations. One thing that is not of any doubt is that drinking water world wide is declining. it is not some sort of bizaare or irrational idea that agriculture could become more efficient in its use of water, and we could all become more efficient energy users if we had the appropriate and readily available equipment and processes. As this planet is the only one we have on which to live, it only makes sense to maintain and take care of it – the very same way you maintain and take care of your home. It doesn’t have to be “rocket science”, and debating whether climate change is real or not is wasting time that could be used in adapting to the new climate that we are living in.
I am sure there are many many business opportunities in preparing people to be more energy and water efficient. It is true that the climate changes on a cyclical basis, and this time the cycle has been speeded up by human beings. That, however, is no reason to ignore what is happening, whatever you believe. And in the process we may save some ecosystems that are valuable and worthy of protection for our own and our children’s sake.
“There has been a substantial increase in most measures of Atlantic hurricane activity since the early 1980s, the period during which high quality satellite data are available.”
The early 1980s was also the time of lowest Atlantic hurricane activity, so any trend since then can only be upward. Of course geostationary satellite coverage of the Atlantic goes back to 1972 and polar orbiting satellites to the early 1960s. Why not start there? Because hurricanes were more frequent back then and would screw up the trend line.
“The recent increases in activity are linked, in part, to higher sea surface temperatures in the region that Atlantic hurricanes form in and move through.”
These are changes in the AMO and PDO, which are unrelated to climate change, and have a much stronger influence on Atlantic hurricane numbers than any global warming trend. But the report goes on to throw GHG increases into reasons for changes in the hurricane numbers. This whole section is spinning faster than a Cat Five.
Heavy downpours.
Despite the graph, it would appear that all records for periods of less than 24 hours occurred in 1960 or before. Only 5 out of 24 spot rainfall records have occurred since 1960.
http://www.wunderground.com/blog/weatherhistorian/what-is-the-most-rain-to-ever-fall-in-one-minute-or-one-hour
Over reliance on Doppler radar data?
Ooops! The last paragraph was mine.
There is a selection bias that is guaranteed to produce headlines (if desired) no matter what data you look at. Since extreme weather moves around from year to year, if you pick the place with (say) the highest temperature, then its almost guaranteed that that will be the highest ever temp IN THAT STATE, even if the overall max temp is not changing from year to year.
May 6, 2014 at 8:22 am
” “… intelligentsia” in D.C. …”
Please excuse my posting of an obvious oxymoron. My bad.
As all successful dictators in the past have learned, the best way to control the population is through fear and ignorance. Our so-called intellectual superiors seem to forget that humans aren’t above or outside of nature, we are all part of nature.
So this is what global warming has done in North America according to the White House. What did the IPCC tell us to expect for North America as a result of global warming?
They tell us that global warming has certainly taken place and it is unprecedented on the record. This really is much worse than I thought. What a crock.
i predict that most of these alarmists will be dead before the oceans rise 12 inches. they can go pound sand. hey.. bite me
i predict the demise of the current alarmists before the oceans rise 12 inches. “pay no attention to the man behind the curtain”
Here is the IPCC in 2001.
But hasn’t the average air temperature in CONUS been declining in recent decades? (A chart showing this should be added to the reference pages.)