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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It’s definitely worse than we thought. (The propaganda, I mean.)
Isn’t the trend of winter storms tracking more northward a positive development versus a negative one? Can’t wait till they miss us altogether. Unfortunately that does not seem to be happening of late. They probably embargoed this thing until after the snow was gone in the Northern states, as putting this out when there was snow still falling in April probably would have drawn angry derision from those in the North.
Did chicken little love to pick cherries too?
“Other trends in severe storms, including the intensity and frequency of tornadoes, hail, and damaging thunderstorm winds, are uncertain and are being studied intensively.”
Yeah, right. Anything that does not fit the agenda and cannot be “corrected” away must therefore “uncertain” and thus ignored.
http://climategrog.wordpress.com/?attachment_id=218
Weather is becoming more extreme (except for when it isn’t) …. in a warming world ( that isn’t ). …
yes I think I start to see a pattern in all this: and it’s worse than we thought !
Hold on a minute! Tejas and Arizona hit 100+F in the summer? Get the @ur momisugly#$% outta here….
It must take a lot of effort to stay this stupid.
You will not see any honest data assessments in the report. They cannot afford to. They are easily verified and will be shown to be false. But then that is the kindest thing you can say about this regime.
Is the list of references available?
Has this ever happened before during the Holocene? You bethca. What evidence can they provide to show that this is being caused by man made greenhouse gases?
US mega-droughts are part of the natural climate.
US droughts and mega-droughts during the Holocene
“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.
Observations-
———————
“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”.
Huh? What?
With all this extreme weather you would think that Warren Buffet would have notice and priced accordingly. He is a money man afterall and is no-one’s fool.
Jimbo, 6:59
You are using stale and misleading data by referring to the Fourth Assessment Report. At the time the IPCC was only ‘really sure’ that man was causing weather extremes.
In the Fifth Assessment Report the IPCC is ‘really, really darn sure.’
Below is a wider, global view. Afterall global warming is supposed to be global and not a country that strongly feels the effects of ENSO etc.
Yet they keep pushing for it. Looking for signs in the natural climate changes that take place anyway and blame man. How can they disentangle it? The report points to post 1950 yet they know full well similar extremes occurred before 1950.
They know that they are overstated on hurricane numbers. Here is what they say: “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.” Emphasis on satellite data availability.
There has certainly been an increase in the number of detected small hurricanes far from land, especially short lived ones. These are the kinds of hurricanes that 40 years ago might not have been observed enough to categorize as a hurricane of any class. Today we can ID a hurricane from satellites very quickly.
Here is a paper by NOAA author (and resigned IPCC author) Chris Landsea, which makes the point that in the satellite era, we now have more identified storms, and more storms of short duration, with no trend in bigger storms and those of long duration:
http://www.aoml.noaa.gov/hrd/Landsea/landsea-et-al-jclim2010.pdf
When politicians of all stripes, for whatever reason, see a need to make a point that may be inaccurate, they will often make the point anyway, and expect that repetition in the media will create a “fact” among most readers. George Orwell would approve. Whether the politicians want to create a new “fact” may be due to true belief themselves — they have themselves been convinced that we need to get the people behind costly efforts to adorn the land with wind machines, perhaps — or it may simply be that they need to do what their backers want them to do. Backers in this case means the entire environmental community, who have to be mobilized for the upcoming elections, and it is also the big dollar contributors such as GE, which makes lots of money when wind machines are proliferating.
Judith Curry’s latest post, Profits (?) of Doom, hits on the theme of all the money that can be made by getting behind the frenzy whipped up by the environmental community — meaning that big money backs these causes and does well by them:
http://judithcurry.com/2014/05/05/profits-of-doom/
Here is Landsea’s letter of resignation from the IPCC:
http://cstpr.colorado.edu/prometheus/archives/science_policy_general/000318chris_landsea_leaves.html
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?
More on cynical profiteering from the chaos started by climate change alarmism:
On Judith Curry’s latest link, commenter Scottish Skeptic gives an example of how much $ can be made by politically connected people who rides the political wave. First the link, then Scottish Skeptic’s comment:
http://judithcurry.com/2014/05/05/profits-of-doom/
“A long time ago, before I was moved to look at the evidence on CO2 myself I was a member of the Scottish Parliament Renewable Energy Group. It was run by a few businessmen who were very keen on wind. They controlled the parliamentary group and pushed the issue very hard and I assumed it was principle first and profit second until I spoke to a newcomer one day.
It was still well before much action was seen on the ground and I asked them how they were getting on with securing sites for windmills. They said “not very well. Almost every single site in Scotland has already been bought up by one of the people running the Scottish Parliamentary group”.
In other words, it was all to do with profit. The naive gullible politicians (and even those like me) were just pawns in a huge money making scheme. That was about 13 years ago. Even a single person speaking up should have been enough for even the dumbest politician and civil servant to wake up and smell the con.
But no! The wind profiteers still pour their poison into the ears of the numpties running Scotland and no doubt the con men who started this scam now have 100s of millions of ordinary people’s money in their pocket now – ready to fund the next rip-off scare.”
It’s caused by the upcoming climate conference. :>O
They are walking a tight rope. They want to make the wild claims officially but know full well that it’s not backed by science. They make only short term claims (weather), speculate about the future (climate models), or longer term claims of trends (natural) and link it to man with weasel words.
They only tell half of the truth when they tell it at all. I thought that many studies predicted that the number of hurricanes may decrease but there will be a small increase in stronger ones. They did not mention the part about fewer hurricanes in the section quoted above.
Anthony, this cries out for red-line rebuttals! wow.
I assume they are trying to tell us during the previous 50 years [1914-1964] much of the U.S. has seen less prolonged periods of excessively high temperatures, heavy downpours, and in some regions, severe floods and droughts.
Okay, there is nothing wrong with this proposition except it is not true.
Or one is free to deny the existence of events like the Great Mississippi Flood of 1927 (the most destructive river flood in the history of the United States), the Dust Bowl (the largest mass migration in American history, involving 3.5 million people), world record surface temperature in Death Valley, California (134°F [56.7°C] on July 10, 1913 at Furnace Creek). It is indeed an inalienable right to do so in a free country, however, there is no other term to describe such people accurately than climate denier.
To put things into perspective take a look at the some of the dire effects on man of the Little Ice Age. It was a terrible time of Great Storms disease, crop failures leading to famine and witch hunts, century-scale droughts in East Africa, increases in flood magnitude in mid-continent North America, malaria epidemics, mass migration, cod migrations north stunted, food price inflation, increased frequency of forest fires, drought in equatorial Africa, social unrest and dynastic transition in ancient China, substantial decline in rural prosperity in Norway, decline in average height of northern Europeans, aridity in the circum-Caribbean region, agro-ecological, socioeconomic, and demographic catastrophes, the demise of the Norse Western Settlement in Greenland etc.
Our climate today is wonderful and normal while our biosphere has been greening in recent decades. What is the problem? The weather?