Many scientists claim that global warming brings about extreme weather occurrences worldwide. A new scientific study by the Potsdam Institute for Climate Impact Research indicates that such occurrences during the summer have increased in a disproportionate manner in the past seven years, resulting in destructive heat waves that affect regions such as the U.S. and Europe.

The scientists from the PIK climate institute in Germany say that the observed increases in these extreme heat waves are disproportionate, by duration and magnitude, which is why they decided to further examine the possible reasons behind it.

Dim Coumou, the study’s lead author, says in a statement that the large number of extreme weather conditions lately has puzzled him and other scientists in the study, leading them to analyze large sets of weather data.

The researchers found a link to a recently discovered mechanism that traps giant waves in the atmosphere and changes circulation patterns in the jet streams, weakening one and amplifying another

According to the recent study, a significant part of universal air motion in mid-latitudes usually comes in the figure of wandering waves around the atmosphere, which are termed Rossby waves. As the wave swings north, it draws warm air coming from the tropics to the U.S., Russia or Europe. As it swings south, it does the same in reverse, pulling in the Arctic’s cold air to the warmer regions.

“Behind this, there is a subtle resonance mechanism that traps waves in the midlatitudes and amplifies them strongly,” Stefan Rahmstorf, another author of the PIK study, says in a statement.

When these waves are virtually stalled and significantly amplified, the result is extreme weather conditions. A brief period doesn't cause much ill-effect, but when such devastating periods are extended, the result is severe effects on people and the ecosystems.

In fact, the survey showed, after 2000, the phenomenon has since increased, happening more frequently and becoming nearly twice as common as before. The scientists found that both new data and theory propose a connection to a progression of events in the Arctic. One explanation given was that the white ice cover is sinking fast, with the result that less sunlight is reflected back into space and the water is warming.

“This melting of ice and snow is actually due to our lifestyle of churning out unprecedented amounts of greenhouse gases from fossil fuels,” PIK director and study’s co-author, Hans Joachim Schellnhuber, says in a statement.

There’s a decreasing difference in temperature with regard to other regions as the Arctic quickly warms, says the study. These temperature differences primarily drive atmospheric circulation patterns, which eventually rule the weather.

You can read the complete study in the Proceedings of the U.S. National Academy of Sciences (PNAS) journal made available online.