Study Finds World is Warming…and Cooling

Posted May 5th, 2014 at 8:06 pm (UTC-4)

17-210-Skirble-global-warming-An international team of climate researchers says the world’s climate has warmed at an unparalleled rate over the past century, but has also found that this warming hasn’t occurred everywhere at the same rate.

Their research also indicates that some parts of the world actually cooled during the 100-year time period.

The new study, published in Nature Climate Change, is the first to provide a detailed look at trends in global land warming for the last 100 years, according to the researchers Florida State University and the College of Atmospheric Sciences at Lanzhou University in China.

The paper also provides details on exactly when and where different areas of the world started to either warm up or cool down.

To make their findings, the researchers developed an analysis method that reviewed historical records of land surface temperatures from 1900 through the present for the entire world, except Antarctica.

Researchers Zhaohua Wu, Fei Ji, and Eric Chassignet (l-r) led study that  provided the first detailed look at when and where the earth has warmed up and cooled down. (Meredith Field/Center for Ocean-Atmospheric Prediction Studies)

Researchers Zhaohua Wu, Fei Ji, and Eric Chassignet (l-r) led study. (Meredith Field/Center for Ocean-Atmospheric Prediction Studies)

“Global warming was not as understood as we thought,” said Zhaohua Wu, an assistant professor of meteorology at Florida State University, who led the research team.

With their new data analysis method, scientists were able to provide the kind of details that had been missing from previous climate studies.

They said due to limitations of previous analysis methods in climate research, past studies on global warming didn’t provide information on non-uniform warming in space and time.

Their analytical review of historical records showed noticeable warming first started in and around the areas that encircled the Arctic and also the subtropical regions – the area between the 35th parallel in the Northern and Southern Hemispheres and the Tropics of Cancer and Capricorn, which includes parts of North and South Africa, the Middle East, Southern Europe, North and South America, Asia and Australia.

But the area of the world where they found the largest buildup of warming taking place through present times has been in the mid-latitudes of the northern hemisphere such as the US and Canada in North America, most European countries and Asian countries such as parts of China and Russia.

Along with the warming trends, they found cooling had actually occurred in some parts of the world.

This visualization shows a running five-year average global temperature, as compared to a baseline average global temperature from 1951-1980. (NASA GISS)

This visualization shows a running five-year average global temperature, as compared to a baseline average global temperature from 1951-1980. (NASA GISS)

“The global warming is not uniform,” said research team member Eric Chassignet, director of Florida State University’s Center for Ocean-Atmospheric Prediction Studies. “You have areas that have cooled and areas that have warmed.”

As most of the world was warming up between 1910 and 1980, some areas south of the equator near the Andes were actually cooling down, and then afterwards had no change at all until the middle 1990s.

Wu said that the detailed representation of when and where the world has warmed or cooled made possible by their analysis should provide a greater context to global warming research overall.

Animation of researchers findings.

Rick Pantaleo
Rick Pantaleo maintains the Science World blog and writes stories for VOA’s web and radio on a variety of science, technology and health topics. He also occasionally appears on various VOA programs to talk about the latest scientific news. Rick joined VOA in 1992 after a 20 year career in commercial broadcasting.

2 responses to “Study Finds World is Warming…and Cooling”

  1. Balaraju says:

    Looking at your map, it would seem logical that if CO2 causes warming, there seems to be more warming in the north with a possible tendency for more effect to the east coast of the USA as well as Siberia caused perhaps by the prevailing westerlies. This, of course, would be one of many factors such as the activity of the sun’s energy that varies from year to year.

  2. Jim Davis says:

    About 5 years ago the earths` path around the sun was slightly altered.
    California`s winter and spring became more mild and pushed back summer a month later.
    Possibly there are massive gravitational walls that hold the universe together, and these
    walls breath every few thousand years relaxing time/space fabric.(?)
    Jim Davis