Scientist says drought hurting evergreen trees in Southwest; long-term, could be worst in history

Many scientists have said that this summer's drought may become the norm for the U.S. as climate change contributes to massive droughts. This could have a devastating affect on the nation's crops, as witnessed this summer, and has already started moving corn production north. Extreme drought could also have a huge impact on U.S. forests, as one University of Tennessee researcher concluded in an article published this month in Nature Climate Change.

By analyzing tree ring data from the year 1000 to 2007, researcher Henri Grissino-Mayer, left, and a team of scientists from Los Alamos National Laboratory, the U.S. Geological Survey, the University of Arizona and Columbia University have evaluated how drought affects the productivity and survival of confer trees in the Southwest. Trees grow slowly during drought and will produce smaller rings as a result. During times of plentiful water, they grow fast and will have wider rings.

Grissino-Mayer said the analysis revealed the most recent drought actually began in the late 1990s and has lasted through the following decade, and that it could last even longer, becoming the worst drought in history. "Looking forward to 2050, our climate-forest stress model suggests we will see worse drought and increased tree mortality than we've seen in the past 1,000 years," Grissino-Mayer said. "This drought will be exacerbated by increasing temperatures globally, foreshadowing major changes in the structure and species composition of forests worldwide." (Read more)