what caused the devastating drought in canada and america in the nineteen thirties?

Answer 1

It can't get any more simple than this.
Constant lack of rain causing a SEVERE drought in turn caused the topsoil to blow, therefore it was constant dust being blown around. The longer the drought the more the dust/topsoil..blowed.
Hence the name Dust bowl

It was like a dog chasing his tail, it just went round and round and wouldn't stop until the rains finally came.

1930’s-40’s: Dust Bowl Years of the 1930’s and early 1940’s: Heat and Drought
In Particular: 1930, 1931, 1934 1936, 1940, 1941 for drought and 1934 and 1936 for summer heat and drought
http://www.mcc.missouri.edu/sigwxmo.htm
For understanding of life during the dust bowl read the below link

James Gregory is an Associate Professor of History at the University of Washington.
He is the author of American Exodus: the Dust Bowl Migration and Okie Culture in California and of the forthcoming The Southern Diaspora: Recasting America in Black and White.

http://www.pbs.org/fmc/interviews/gregory.htm

Answer 2

The Dust Bowl Drought

The Dust Bowl drought was a natural disaster that severely affected much of the United States during the 1930s. The drought came in three waves, 1934, 1936, and 1939-40, but some regions of the High Plains experienced drought conditions for as many as eight years. The "dust bowl" effect was caused by sustained drought conditions compounded by years of landPhotos from Library of Congress and U.S. National Archives management practices that left topsoil susceptible to the forces of the wind. The soil, depleted of moisture, was lifted by the wind into great clouds of dust and sand which were so thick they concealed the sun for several days at a time. They were referred to as" black blizzards".

Answer 3

Global...uhhh...ubityubityubity...uhhhh...let's see. The earth's human population was half what it is today....uhhhhh....it was them Buicks. Those bigass Buicks and Packards. Yeah! That's what it was.