Some scientists study tree rings like these to figure out what climates of the past were like. Each year that the tree was alive it grew another ring, making its trunk wider. The thickness of a ring depends on what the weather was like during the year in which it grew.
Image courtesy of UCAR Digital Image Library

Scientists study tree rings like these to figure out what climates of the past were like. Each year that the tree was alive it grew another ring, making its trunk wider. The thickness of a ring depends on what the weather was like during the year in which it grew.
Image courtesy of UCAR Digital Image Library

Scientists study tree rings like these to figure out what climates of the past were like. Each year that the tree was alive it grew another ring, making its trunk wider. The thickness of a ring depends on what the weather was like during the year in which it grew.
Image courtesy of UCAR Digital Image Library

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