A new study has found that global warming has been uneven over the past 100 years.

The study, conducted by Florida State University scientists, has shown that certain regions of the world have warmed while others cooled.

"Global warming was not as understood as we thought," said Zhaohua Wu, an assistant professor of meteorology at FSU.

For the study, researchers used a new analysis method to examine data on land surface temperature changes since 1900. The team used data from all over the world, except Antarctica.

Researchers found that warming began in regions around the Arctic and subtropical regions of the two hemispheres. Northern mid altitude regions have witnessed the largest rise in warming. Some regions have experienced cooling over the past few decades, researchers found.

"The global warming is not uniform," Eric Chassignet, director of FSU's Center for Ocean-Atmospheric Prediction Studies (COAPS), said in a news release. "You have areas that have cooled and areas that have warmed."

From 1910 to 1980, most regions of the world saw a rise in temperatures, but areas lying south of the equator such as Andes cooled down, iscience times reported. Temperatures remained more or less stable till the 1990s.

"Global warming was not as understood as we thought," said Zhaohua Wu, an assistant professor of meteorology at FSU, according to a news release.

According to Wu, finding when and which regions experienced periods of warming or cooling will help researchers understand the impact of climate change.

The study is published in the journal Nature Climate Change.

Some regions have already been affected by the rise in temperature. The tiny island-nation of Kiribati recently became the first country to announce evacuation plans due to global warming.