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Federal Advisory Committee Draft Climate Assessment Report

February 6, 2013
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By Paul Homewood



The US government, or more specifically their National Climate Assessment and Development Advisory Committee, have just released their draft climate report, which states that “Climate change is already affecting the American people”.

One claim made is that “certain types of weather events have  become more frequent and/or intense, including heat waves, heavy downpours, and, in some  regions, floods and droughts.”

This is all very strange, because the US Geological Service issued their own report in 2011, saying the exact opposite. According to them:-


Only one of four large regions of the United States showed a significant relationship between carbon dioxide (CO2) in the atmosphere and the size of floods over the last 100 years. This was in the southwestern region, where floods have become smaller as CO2 has increased.

A new report published by U.S. Geological Survey scientists in the Hydrologic Sciences Journal looks at this potential linkage using historical records of floods throughout the nation. Scientists studied flood conditions at 200 locations across the United States looking back 127 years through 2008.

"Currently we do not see a clear pattern that enables us to understand how climate change will alter flood conditions in the future, but the USGS will continue to collect new data over time and conduct new analyses as conditions change," said USGS scientist and lead author Robert Hirsch. "Changes in snow packs, frozen ground, soil moisture and storm tracks are all mechanisms that could be altered by greenhouse gas concentrations and possibly change flood behavior. As we continue research, we will consider these and other factors in our analyses."

The decrease of floods in the southwestern region is consistent with other research findings that this region has been getting drier and experienced less precipitation as a likely result of climate change.

Climate changes that could influence flood magnitudes include shifts in the intensity and tracks of various types of storms and changes in the type of precipitation (rain versus snow). The conditions on the landscape when large storms arrive can also change (for example, smaller snowpacks, less soil moisture and less frozen soil). All of these can influence the size of floods. Of course, human activities within the watershed can also have a major influence in the size of floods. These include urbanization, building of dams and levees, and shifts in vegetation types and drainage of soils and wetlands. At the present time, we see much larger changes in flooding from these causes than we can see from greenhouse forcing.

The draft report contains many more such alarmist claims, but if it so inaccurate regarding floods, is it worth the paper it is written on?

  1. February 6, 2013 9:22 pm

    Here’s the part I have a problem with (from the Alaska and Arctic report):

    “Over the past 60 years, Alaska has warmed more than twice as rapidly as the rest of the U.S., with state-wide average annual air temperature increasing by 3°F and average winter temperature by 6°F. This warming involves more extremely hot days and fewer extremely cold days (Stewart et al. 2013; U.S. Global Climate Change Science Program 2008). Because of its cold-adapted features and rapid warming, climate-change impacts on Alaska are already pronounced, including earlier spring snowmelt, reduced sea ice, widespread glacier retreat, warmer permafrost, drier landscapes, and more extensive insect outbreaks and wildfire, as described 33 below.”

    So what’s the problem? This is the problem:

    And the US mainland trend over the same period is +0.46F/decade (NOAA).

    That may be worth bringing to their attention although my street-wise brain says they are already aware.

  2. February 6, 2013 9:24 pm

    And for some reason, I couldn’t find any reference to this:

  3. John F. Hultquist permalink
    February 6, 2013 9:26 pm

    Follow the money.

    The “Advisory Committee” seems like a well intentioned bunch. The intention is to keep taxpayer money flowing to their groups based on the long-in-the-tooth false AGW issue until they can think up another scary story. The next one will by either #27 or #28, I think, see this:

    Climate seers as blind guides — post by J. Scott Armstrong
    Anthony Watts now has this on his site, one or two posts down on 2/6/2013.

  4. John F. Hultquist permalink
    February 7, 2013 5:01 pm

    The link provided by mpcraig @ 9:24 provides and example of how an interesting study gets wrapped in AGW boilerplate. They mention the PDO and explain how when it changes to dominantly negative, the Aleutian Low weakens. They explain further how this has caused Alaska to cool in the first decade of the new century.

    However, just before an acknowledgement of those responsible for the financial support for the work, they cite CO2, stating:
    “In summary, the long term observed warming of Alaska
    of about twice the global value, as expected by the increasing
    CO2 and other trace gases, is sometimes temporarily
    modified or even reversed by natural decadal variations. This
    is not the first observed occurrence that can be found in the
    historical record of Alaska [14], as the 1920’s were warm,
    and starting in the mid-1940’s a cold period occurred lasting
    some 3 decades, after which it become warm again.”

    Note how easily one could quote just the first half of this as “proof” that a study found the AGW expected warming.

    Many years ago a paper I wrote was quoted out-of-context. Ever since then I read with this in mind. I’m not saying such will be the case with this paper – only that it easily could be done.

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