Have you noticed that March, and so far April, weather has been noticeably cool? Daily average temperatures are running about five degrees below normal and the early morning hour temperatures have been closer to eight degrees below average. Numerous low temperature records have been broken around the area over the past several weeks. So are the current cool conditions a sign of climate change or just a reflection of typical seasonal variations?
There are simple parameters that can be observed and monitored to help detect both seasonal variations and what may be longer term changes in climate. For example, in the Keizer-Salem area, Red Bud trees generally bloom beginning April 15th but blooming can occur earlier or later depending on early springtime temperatures. In Alaska, they monitor “ice-out” dates on local rivers which dates, when compared to historical averages, provide useful climate trend lines. Whether it is ice out in Alaska or on the Great Lakes or the first springtime appearance of bees and blossoms in your yard, there are clues as to the state of the atmosphere and climate. Being observant and keeping a record of the dates of these annual occurrences can be both fun and useful.
After several consecutive drier than normal years, this winter has brought closer to expected precipitation to western Oregon. Presently we are a bit dry again and northwest Oregon could quickly slip back into abnormally dry conditions and, once again, drought. The current east wind weather pattern is a drying pattern and farmers are already irrigating some of their fields! Most of Oregon and the rest of the west is currently experiencing drought. In California, based upon observations and modeling, scientists and engineers are planning for shorter but more intense winter wet seasons and the changes to water storage management plans that will be required. Similar changes in water management may also become necessary in the northwest.
Things change with climate and always have. It is now known that about 400,000 years ago, Greenland was ice free. The last ice age affecting Oregon was ending about 11,000 years ago. We may in fact still be melting out from the last ice age. Ice ages predictably come and go but the frequency and timing of ice ages can be altered by global warming. Whether you agree or disagree with climate change, one clue that might persuade you is this: all five of the warmest years on record for the continental United States have occurred within the past decade.
This year is the 21st anniversary of the “U.S. Drought Monitor”, a service provided by the USDA and NOAA. The Drought Monitor publishes weekly and monthly updates to changing drought conditions across the country. The USDM website is easily found and offers useful information for daily and seasonal planning affecting farming and land and water resource management. Whether you agree or disagree with the concept of climate change or global warming, it is a good time to become aware of current conditions and what changes likely lie ahead.
(Jim Parr lives in Keizer.)
