Margaret Hiza Redsteer uses Navajo memories to track climate change

Margaret Hiza Redsteer has long known the Navajo Nation. Of Crow descent, she grew up near the Montana-Wyoming border, and in the 1970s moved to an area of Arizona then shared by the Navajo and Hopi tribes. She married a Navajo man and they had three children. While living on the reservation, she often heard people talk about how much the land's vegetation had changed. "But at that point," she says, "it hadn’t really clicked what that meant – that it indicated climate change."

In 1986 the 29-year-old Hiza Redsteer and her family resettled in Flagstaff, where she began to study geology at the university. After 14 years of schooling, she returned to the Navajo Nation with a Ph.D., as an employee of the U.S. Geological Survey in the early 2000s. Her research specialty was studying volcanic deposits near Yellowstone. But, as she grew convinced of the harmful effects of climate change on reservation livelihoods, she decided to switch focus. Her pioneering work using aerial photographs, GPS maps and remote laser sensing data to track landscape level changes on the Navajo Nation was written about in "Shifting sands in Navajoland," (HCN story; 6/23/08).

Now, Hiza Redsteer is pushing to find out even more about ecological changes her original data could not track by incorporating a rarely-used form of climate data into her research -- the accounts of Indian elders. She has extensively interviewed many elders, and now their perspective is illuminating new aspects of the region's environmental history.

High Country News If I was a Navajo child, what would I hear about the weather and climate growing up?

Margaret Hiza Redsteer The elders often talk about the difference in grass, how tall, how thick, how much of it there used to be. Some people say when they were young and herding sheep they had to stay right with the herd. If they didn’t the sheep would get lost in the grass. It's not like that now.

HCN What have you learned from these oral histories?

Hiza Redsteer The elders' memories can give us information that the physical records can’t. They give a much better picture of what the ecological changes have been. For example, people talk about how, in the winter, the snow was chest high on the horses. They talk about using particular streams for irrigation of crops, but many of those aren’t even flowing now,

It helps us fill in gaps too. There are huge time gaps in some of the earlier photography. We have a photo set from 1936, for instance, but then the next photo set we have from the area is from 1954. That’s a huge gap in time when you’re trying to unravel how the landscape changed and what caused it.

HCN Is there a difference between the kind of information you can get through oral and analytical methods?

MHR We can model evapotranspiration rates based on temperature; we can make observations of soil moisture. But one thing that we can't do very easily is project back to what those conditions were like when there was more snow. One of the things we’ve learned (from oral accounts) is that soil moisture conditions were much different. In the Southwest we expect precipitation during two distinct periods: winter rains, followed by a dry windy spring, then the summer monsoons. Springs have become much warmer; we can see that in the meteorological record.

We've learned from the elders that the soil stayed moist all through the spring until the summer monsoon arrived. Now, if you were to go out in the springtime during the dry windy season, you could dig a very big trench and not run into any wet sand or soil. The ecological effects are huge because shallow rooted plants aren't going to do as well.

It's also hard to reconstruct where plants and animals were in the past. The elders have told us that when there were cottonwoods in the Little Colorado river there were lots of beavers. They used to see cranes migrate through the area in the spring, stopping in the marshes around lakes that aren't there now.

• Climate Change