Capsule summary of the paper published in the Table of Contents, Nature Climate Change, June 2013:
Trends in hourly rainfall statistics in the United States under a warming climate
Has the frequency of ‘extreme weather events’ changed with climate warming over the last century? Using hourly precipitation records from thirteen sites, this study finds no evidence for significant changes in mean ‘storminess’ across the United States.
Trends in hourly rainfall statistics in the United States under a warming climate
T. Muschinski & J. I. Katz
Abstract: It is now widely accepted 1, 2, 3, 4, 5 that the mean world climate has warmed since the beginning of climatologically significant anthropogenic emission of greenhouse gases. Warming may be accompanied 6, 7, 8 by changes in the rate of extreme weather events such as severe storms and drought. Here we use hourly precipitation data from 13 stations in the 48 contiguous United States to determine trends in the frequency of such events, taking the normalized variance and a renormalized fourth moment of the precipitation measurements, averaged over decades, as objective measures of the frequency and severity of extreme weather. Using data mostly from the period 1940–1999 but also two longer data series, periods that include the rapid warming that seems to have begun at approximately 1970, we find a significant increase of 6.5±1.3%(1σ) per decade in the normalized variance at a site on the Olympic Peninsula at which it is low. We place statistical limits on any trend at the remaining 12 sites, where the normalized variance and its uncertainty are larger. At most sites these limits are consistent with the same rate of linear increase as at the Olympic Peninsula site, but exclude the same rate of percentage increase.
Abstract: It is now widely accepted 1, 2, 3, 4, 5 that the mean world climate has warmed since the beginning of climatologically significant anthropogenic emission of greenhouse gases. Warming may be accompanied 6, 7, 8 by changes in the rate of extreme weather events such as severe storms and drought. Here we use hourly precipitation data from 13 stations in the 48 contiguous United States to determine trends in the frequency of such events, taking the normalized variance and a renormalized fourth moment of the precipitation measurements, averaged over decades, as objective measures of the frequency and severity of extreme weather. Using data mostly from the period 1940–1999 but also two longer data series, periods that include the rapid warming that seems to have begun at approximately 1970, we find a significant increase of 6.5±1.3%(1σ) per decade in the normalized variance at a site on the Olympic Peninsula at which it is low. We place statistical limits on any trend at the remaining 12 sites, where the normalized variance and its uncertainty are larger. At most sites these limits are consistent with the same rate of linear increase as at the Olympic Peninsula site, but exclude the same rate of percentage increase.
This approach was similar to the "20th Century Climate Reanalysis" where 135 years of observations documented every 6 hours, showed no indication that extreme weather was increasing. The program was defunded when the desired results were not evident.
ReplyDeleteYes it is warmer today than it was a century ago. And yes, CO2 emissions have risen, significantly , in that same century. But, it does not follow that there is any proof that the CO2 emissions are the basic cause of the temperature increase. In the 21st century CO2 emissions have risen even faster, yet the world temperatures have remained flat.
ReplyDeletedoes the increase in CO2 cause some warming, yes. The big debate is: How much warming is due to humans VS natural forces. Is it a human hair, skeptics position, or a sheet of paper, alarmists position, on a mile long measuring stick? Is it worth spending 100 TRILLION to fix a non problem?
DeleteThere is no creditable experiment that proves that the Greenhouse gas effect exists. This is more circumstantial evidence that supports the fact that the GHGE does not exist.
ReplyDeleteThere is an experiment that proves that the Greenhouse gas effect does not exist. This experiment which has been technologically reviewed by Ph.D. physicists . Ph.D. Chemical engineers and others. The experiment is found on the web-site http:// www.slayingtheskydragon.com click on the blog tab, page 3. It is titled "The Experiment that failed which can save the world trillions-Proving the greenhouse gas effect does not exist"
Dr. Vincent Gray on historical carbon dioxide levels
ReplyDeletePosted on June 4, 2013 by Anthony Watts
NZCLIMATE TRUTH NEWSLETTER NO 312 JUNE 4th 2013
CARBON DIOXIDE
There are two gases in the earth’s atmosphere without which living organisms could not exist.
Oxygen is the most abundant, 21% by volume, but without carbon dioxide, which is currently only about 0.04 percent (400ppm) by volume, both the oxygen itself, and most living organisms on earth could not exist at all.
This happened when the more complex of the two living cells (called “eukaryote”) evolved a process called a “chloroplast” some 3 billion years ago, which utilized a chemical called chlorophyll to capture energy from the sun and convert carbon dioxide and nitrogen into a range of chemical compounds and structural polymers by photosynthesis. These substances provide all the food required by the organisms not endowed with a chloroplast organelle in their cells.
This process also produced all of the oxygen in the atmosphere
The relative proportions of carbon dioxide and oxygen have varied very widely over the geological ages.
Oxygen_earths_atmosphere_historical
CO2_temperature_historical
It will be seen that there is no correlation whatsoever between carbon dioxide concentration and the temperature at the earth’s surface.
During the latter part of the Carboniferous, the Permian and the first half of the Triassic period, 250-320 million years ago, carbon dioxide concentration was half what it is today but the temperature was 10ºC higher than today . Oxygen in the atmosphere fluctuated from 15 to 35% during this period
From the Cretaceous to the Eocene 35 to 100 million years ago, a high temperature went with declining carbon dioxide.
The theory that carbon dioxide concentration is related to the temperature of the earth’s surface is therefore wrong
No it wasn't warmer a hundred years ago, some of the heat records were set..... around a hundred years ago.
ReplyDeleteWe heard so much about Death Valley this year, well here are some facts from a hundred years ago "In 1913 they had five days in row hotter than this year’s hottest day, including 134F on July 10"