I write and talk a lot about the effects Mother Nature has and has had on people and communities. You can read my list of published articles and books on this site here. My presentations are summarized here. I also try to maintain a bibliography of books and articles about the relationships of natural phenomena and family history. You can see the reading list here.
We are
constantly bombarded (or so it seems lately) with news headlines and opinion
pieces about natural disasters around the world, in many cases because of their
purported connection with climate change. Differing opinions exist that events
that we are observing now, around the world, are unique in terms of intensity,
history and their impact on human settlements.
Many are
related to short and long-term weather patterns: droughts, heat waves (the polar
vortex in the winter), floods, storms, wildfires, etc. Other disasters that are
part of the Earth’s normal geological processes include earthquakes,
landslides, volcanic eruptions and tsunamis. All, of course, can cause distress
and mayhem to people. As they have done for eons!
A short
list of recent major events includes:
·
Drought
in Western Canada, Western USA and around the world
·
Earthquakes
in Japan, Russia, USA
·
Floods
in New York and New Jersey (and Algeria, Australia, Bolivia, China, the Congo, Jordan,
Nigeria, USA
·
Glacier
collapse in Switzerland
·
Storms
(including hurricanes and tornadoes) in Australia, Canada, Egypt, Kuwait, the
Philippines, Tunisia, UK, USA
·
Wildfires
in the Southeast Europe, Canada, Korea, USA
·
Volcanic
eruptions in Iceland, Indonesia, Russia
News
reports and some studies state that events are getting worse – in frequency,
intensity and regional scope. But these comments only relate to a few past
decades, not to the overall historical record.
The costs
associated with damage from natural disasters have reached record levels. But
they are mainly in areas where there are large populations and highly developed
infrastructure. Would anyone doubt that the relative cost of the drought and
fires in Europe in 1540 or 1842 would be much different on a per capita basis?
Our records
of natural events, including written historical documents, only go back a few
hundred years, in most regions much less time. For example, you can read about
major storms in millions of newspaper articles going back to the early 18th
century.
Geological
and geographical records show major catastrophic events have occurred regularly
in past centuries and over hundreds of millions of years.
Regarding
family history studies, it is informative to look at what is going on in the
modern world to appreciate how such events may have affected our ancestors, who
were not likely to have been as well prepared or warned about impending natural
disasters.
To take one example of the present and relate to outcomes in the past, we can look at the drought conditions plaguing western North America. The current ongoing megadrought began in 2000. Such dry periods have not been rare occurrences in this region.
The medieval era in western North America was also characterized by widespread and regionally severe, sustained droughts. Proxy data, primarily in the form of tree rings, indicate decades-long periods of increased aridity illustrated as peaks on the graph and shown as red on the map from AD 1150 across the central and western U.S.
In the
Colorado and Sacramento River basins, reconstructions show long periods of
persistently below average river flows during several intervals including much
of the 9th, 12th, and 13th centuries.
Other proxy
records include the position of tree lines, melting of glaciers and the types
of chironomids present. Chironomids are a distinct group of lake flies whose
populations and types can be correlated with specific climatic conditions.
All these
proxies are consistent in supporting periods of elevated warmth in the medieval
period that coincide with periods of severe and widespread drought. The driest
episode was in the mid-12th century and was more extensive and
persistent than any modern drought experienced.
One of the casualties of the long drought was the collapse of the Anasazi or
Ancestral Pueblo society that had thrived for hundreds of years in the
southwest part of North America. A series of megadroughts of the 10th to 13th
centuries finally took their toll on the residents and forced them to move.
More recent
droughts that may have impacted our ancestors, possibly droving them to
migrate, that we can learn about in published records and family stories
include: the 1930s Dust Bowl; the Great Plains droughts in the 1890s, 1870s and
1860s; central Europe in the 1840s; 1790s in Australia; 1760s in the British
Isles; early 1600s in the American colonies; and the mid-16th
century in Europe.
Drought is
a normal, recurrent feature of climate that occurs in virtually all climate
zones. Further to that thought, droughts have occurred virtually every year
someplace and megadroughts have been experienced at least once per century, not
uncommonly more frequently. The Earth will certainly continue to experience
them in the future.
One wonders
if residents living in the dry southwest region now could move, would they?
References
and Data Sources
Ancestral
Puebloans https://en.wikipedia.org/wiki/Ancestral_Puebloans
Southwestern
North American megadrought https://en.wikipedia.org/wiki/Southwestern_North_American_megadrought
The U.S.
Drought Monitor (USDM) is a map released every Thursday, showing where drought
is and how bad it is across the U.S. and its territories. https://droughtmonitor.unl.edu/CurrentMap.aspx
The
National Integrated Drought Information System (NIDIS) is a multi-agency
partnership that coordinates current drought monitoring, forecasting, planning,
and information internationally and also historically. https://www.drought.gov/international
The North
American Drought Monitor (NADM) is a cooperative effort between drought experts
in Canada, Mexico and the United States to monitor drought across the continent
on an ongoing basis. https://www.ncei.noaa.gov/access/monitoring/nadm/maps
The Global
Drought Information System (GDIS) is a tool for visualizing drought related
data across the globe. https://gdis-noaa.hub.arcgis.com/
The
Canadian Drought Monitor (CDM) is Canada's official source for the monitoring
and reporting of drought nationally. https://agriculture.canada.ca/en/agricultural-production/weather/canadian-drought-monitor
Copernicus
is an EU program aimed at developing European drought information services
based on satellite Earth Observation and in situ (non-space) data. https://drought.emergency.copernicus.eu/
