Weather agencies in Australia, Paraguay and Switzerland may be manipulating temperature data to create a sharper warming trend than is present in the raw data — a practice that has come under scrutiny in recent months.

Most recently, Dr. H. Sterling Burnett with the Heartland Institute detailed how the Swiss Meteorological Service adjusted its climate data “to show greater warming than actually measured by its temperature instruments.”

In his latest article, Sterling wrote that Switzerland’s weather bureau adjusted its raw temperature data so that “the temperatures reported were consistently higher than those actually recorded.” For example, the cities of Sion and Zurich saw “a doubling of the temperature trend” after such adjustments were made.

But even with the data tampering, Sterling noted that “there has been an 18-year-pause in rising temperatures, even with data- tampering.”

“Even with fudged data, governments have been unable to hide the fact winters in Switzerland and in Central Europe have become colder over the past 20 years, defying predictions of the Intergovernmental Panel on Climate Change (IPCC) and other climate alarmists,” according to Sterling.

The Swiss affair, however, is not the first instance of data “homogenization” catalogued by scientists and researchers who are skeptical of man-made global warming. In January, skeptic blogger Paul Homewood documented how NASA has “homogenized” temperature data across Paraguay to create a warming trend that doesn’t exist in the raw data.

Homewood found that all three operational rural thermometers in Paraguay had been adjusted by NASA to show a warming trend where one did not exist before. Homewood also found that urban thermometers in Paraguay had similarly been adjusted by NASA.

“[NASA is] supposed to make a ‘homogenisation adjustment,’ to allow for [urban heat island (UHI)] bias,” Homewood wrote. “The sort of thing you would expect to see at Asuncion Airport, Paraguay’s main gateway, handling over 800,000 passengers a year.”

“However, far from increasing historic temperatures to allow for UHI, [NASA] has done the opposite and decreased temperatures prior to 1972 by 0.4C,” Homewood added.

Before that, the Australian Bureau of Meteorology (ABM) was forced to admit it adjusts temperatures recorded at all weather stations across the country. Aussie journalists had been critical of ABM for being secretive about its data adjustments.

“Almost all the alterations resulted in higher temperatures being reported for the present and lower numbers for the past–with the higher numbers being used to demonstrate a historical warming trend–than the numbers that were actually recorded,” wrote Sterling.

“Downward homogenizations in recent years were rare. In some areas, downward temperature trends measured over time showed a significantly increased temperature trend after homogenization,” he added. “The difference between actually measured temperatures and homogenized temperatures topped 4 degrees Celsius over certain periods at some measuring stations.”

Global warming skeptics have increasingly become critical of adjustments to raw temperature data made by government climate agencies. Such adjustments seem to overwhelmingly show a massive warming trend not present in the raw data.

Such adjusted data has been used by climate scientists and environmental activists to claim that 2014 was the warmest year on record. Adjusted data also shows that 13 of the warmest years on record have occurred since 2000.

NOAA and other climate agencies have defended such adjustments to the temperature record, arguing they are necessary to correct for “biases” that distort the reality of the Earth’s climate.

NOAA scientists increase or decrease temperatures to correct for things like changes in the locations of thermometers (some that were once in rural areas are now in the suburbs or even in cities). Scientists have also had to correct for a drastic change in the time of day temperatures were recorded (for whatever reason, past temperatures were recorded in the afternoon, but are now often collected in the morning).

Other adjustments have been made to the data to correct for such “biases,” but global warming skeptics question if the scope of the data adjustments are justifiable.

The U.K.’s Global Warming Policy Foundation has created a panel of skeptical scientists from around the world who will evaluate temperature adjustments to find out if they are scientifically justified.

“Many people have found the extent of adjustments to the data surprising,” Terence Kealey, former vice-chancellor of the University of Buckingham, said in a statement.

“While we believe that the 20th century warming is real, we are concerned by claims that the actual trend is different from — or less certain than — has been suggested,” said Kealey, who has been appointed chairman of the foundation’s investigative task force. “We hope to perform a valuable public service by getting everything out into the open.”

Follow Michael on Twitter

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.