Controlling Nature in potatoes provided some 25, pounds. Potato production took off
in countries like Ireland. Within two centuries, its population had grown
from .5 million to .5 million people subsisting on a diet of mostly milk
and potatoes.
Meanwhile, on islands off the shores of Peru, vast reserves of guano
had been discovered. Guano (excrement deposited by seabirds) was
brought to Europe as fertilizer to put on crops like potatoes. But along
with the guano came a pathogen that, during an unusually damp spell,
spread throughout Ireland and destroyed most of the potato crop. Before
it was over, the resulting famine claimed one million lives and chased
two million people from their homeland.
Explorers, conquerors, and settlers crisscrossing oceans were doing
more than claiming new land and expropriating the riches they found.
They were also bringing along microscopic organisms, introducing
exotic bacteria, viruses, fungi, pathogens, and pests that redefined the
environment and decimated native populations.
New microbes were not the only unwelcome change. Back in
America’s Great Plains, in the half century leading up to the 3 s,
homesteaders plowed under drought-resistant grasses and planted non-
drought-resistant wheat. Ranchers co-opted and overgrazed millions of
acres of unattended public lands. “Suitcase farmers,” who were attracted
by seemingly plentiful rains but who had no intention to stay and home-
stead, showed up just long enough to plant then return to harvest their
crops. Total land cultivated increased from 2 million to 3 million
acres.
But then the rains ceased and the moisture in the soil evaporated.
Without the native grasses to hold topsoil in place, sand and dirt were
lifted by prevailing winds to form dust storms. Suitcase farmers stopped
coming around. The Dust Bowl was under way and the widespread
erosion that followed persisted for a decade. “Funnel storms” carried
dust four miles into the atmosphere and transported it to cities like New
York and Washington, DC. Chicago was blanketed with up to four feet
of dust from a single storm. In the Southern Plains, black storms turned
day to night and paralyzed travel.
Six years into what is now known as the Dust Bowl era or the “Dirty
Thirties,” an estimated four out of every five acres across the Great
Plains were in some stage of erosion. Farmers placed the blame on