The impacts of climate change stretch from the loss of polar bear habitat to African crop failures to threatening a seasonal festival among Native Americans that they believe is critical to keep the world in balance.
The traditional calendar of the Tohono O'odham nation, whose reservation straddles the U.S.-Mexican border, starts with the summer solstice. The ensuing months follow the pace of nature.
"Right now, the seasons are offset because of global warming," Verlon Jose, vice chairman of the nation of 34,000 people, told the Thomson Reuters Foundation during a recent visit to the reservation.
"The weather is crazy. So is the calendar," he said.
Now is the calendar's month of yellow in the desert, when the Palo Verde trees and brittlebush flowers bloom. It is time to harvest the edible cholla cactus buds and, soon, the pulpy red fruit of the tall Saguaro cactus.
At the height of summer comes one of the Tohono O'odham's most sacred and secret ceremonies, its timing now at the mercy of the unpredictable climate, Jose said.
The ceremony, once a full two weeks, is already endangered as fewer people can find time to attend, he said.
"An elder told me if this ceremony ceases to exist, the world will be no more. In order for the world to be in balance, we do this for the world," he said.
The Tohono O'odham people of the Sonoran Desert still live on their ancestral lands, although their territory once stretched hundreds of miles further than it does today. They take cues from nature to decide when to hunt, sow crops and harvest food.
"We watch the plants. We watch the elements, the rain, the wind. All of those things are messages to us," Jose said.
Now, "in the winter the snakes are confused because November and December when they are usually hibernating, they are still out," he said.
"The plants, the flowers, they don't know when to bloom because the weather is changing," he said.