Texas Trends > Climate Trends

There is growing concern that climate change will adversely affect people and the ecosystems on which they depend (The National Academies 2008).

Climate Change

Climate change could impact forests and other ecosystems through changes in rainfall, both in amount and distribution, and storm frequency and intensity. These changes in climate could also affect the occurrence and severity of wildland fire.

Cyclical Weather Patterns

Oceanic conditions in both the Atlantic and Pacific Oceans seem to influence long-term drought conditions within the U.S. Scientists monitoring both oceans have been able to match the changing phases of multi-decadal oscillations within each ocean to the presence or absence of drought.  The oscillations are called multi-decadal because they can last as long as 30 years.   In the Pacific, this event is called the Pacific Decadal Oscillation (PDO).  In the Atlantic, it is called the Atlantic Multi-Decadal Oscillation (AMO). 

Since 1996, Texas has experienced extended dry periods with severe fire seasons in 1996, 1998, 1999, 2000, 2005, 2006, 2008 and 2009.  It appears from the PDO and AMO charts that Texas experiences a long-term drought cycle when the PDO is in the cool (or negative phase) and the AMO is in the warm (or positive phase).  This was the case during the droughts of the 1950s and 1960s.  If history can be used as an indicator of what to expect in the future, and the PDO and AMO are in fact indicators of prolonged drought periods within the state, the current weather pattern could likely last another 15 to 20 years.  Several more dry years over this time span would have significant impacts on wildfire occurrence, water resources, land use, tree health, and ultimately the citizens of Texas.  These weather related effects should be considered in any strategic or tactical response plans.


Birdsey, R.A. 1992. Changes in forest carbon storage from increasing forest area and timber growth. In:Forests and global change: forest management opportunities for mitigating carbon emissions (vol. 2) eds. R.N Sampson and D. Hair, 1-26. Washington, DC: American Forests.

Brown, T. J., B. L. Hall, and A. L. Westerling. 2004. The impact of twenty-first century climate change on wildland fire danger in the western United States: an applications perspective. Climate Change 62:365-388.

The National Academies. 2008. Understanding and responding to climate change: highlights of National Academies Reports 2008 edition. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1048006.pdf

Westerling, A. L., A. Gershunov, T. J. Brown, D. R. Cayan, and M. D. Dettinger. 2003. Climate and wildfire in the western United States. Bulletin of the American Meteorological Society 84(5): 595-604.