NASA scientists have determined the drought of 1934 was the worst in North American history over the last thousand years, due to the dust storms that occurred during the "Dust Bowl" time period.
By using a tree-ring based drought record from the years 1,000 to 2005, alongside modern records, scientists from the U.S. space agency and the Lamont-Doherty Earth Observatory determined the drought in 1934 to be up to 30 percent more severe than the second-worst drought in 1580, according to a NASA release.
It spanned across 71.6 percent of western North-America, according to the study. In comparison, the average extent of the 2012 drought was 59.7 percent.
"In combination then, these two different phenomena managed to bring almost the entire nation into a drought at that time," said Richard Seager, co-author of the new study, in a news release. "The fact that it was the worst of the millennium was probably in part because of the human role."
What caused the 1934 drought was the high-pressure system that sat throughout winter and shifted over the west coast of the U.S. This pressured turned away all wet weather, in a similar way to the one of 2013 and 2014, according to the release.
Dust storms during that time helped further suppress rainfall.
Climate change will continue to strengthen the possibilities of strong droughts in North America, according to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).
"We found that a lot of the drying that occurred in the spring time occurred downwind from where the dust storms originated, suggesting that it's actually the dust in the atmosphere that's driving at least some of the drying in the spring and really allowing this drought event to spread upwards into the central plains," said Ben Cook, climate scientist, according to the release.
These findings helps revealed the importance of resisting climate change, and could also explain why California is going through its current drought.
See Now: OnePlus 6: How Different Will It Be From OnePlus 5?