Study links humans to warming trend in Pacific Northwest

CORVALLIS, Ore. -- Humans are the link to a warming world, according to researchers at Oregon State University and University of Idaho.

Philip Mote, director of OSU's Oregon Climate Services, worked with two other scientists to publish the study that links global warming directly to humans.

"We put stuff in the atmosphere, green house gasses and also pollutants that reflect sunlight and form clouds, and that increase in heat-trapping gasses, is the only thing that can explain the large warming trend since 1950," said Mote.

"Carbon dioxide, methane, nitrous oxide, these are all gasses that are naturally occurring," he continued, "but have gone up dramatically in the last 50 to 100 years because of what humans are doing."

The study gathers data from 141 weather stations in the Pacific Northwest, compiling data from 1901 to 2012. They found that the annual mean regional temperature increased by about 1.3 degrees Fahrenheit since the turn of the century.

A similar 1.3 degree F shift means snow levels would rise about 600 feet.

"In some stations, mostly east of the Cascades, those warming trends have been as much as 8 degrees Fahrenheit.

The researchers also looked at a number of factors from year to year and decade to decade - and found weather patterns and natural causes were not the reason for warmth.

"All the natural factors together failed to explain the warming. Solar variability, volcanic eruptions, what the atmosphere over the Pacific Ocean is doing," said Mote.

He said it's interesting to note that precipitation amounts were not affected as much as temperatures.