News events that affect your Middle Tennessee landscape
We have to adapt to our changing climate
by Linda Roberts Phipps
Sunday, 05/13/07
I've worked as a consultant in the environmental field for more than 20 years, and I've been teaching environmental science for more than seven, but just like almost everybody else this spring, I stocked up on plants and flowers during that wonderful, unseasonably warm week in March.
There I was, out in the yard, planting flowers and helping my kids plant a vegetable garden, enjoying the summer-like weather. And just like everyone else, I watched my new bedding plants, and even some of my trees and shrubs, succumb to the deep freeze two days later in April (although we did manage to save some of the kids' vegetable plants).
I should have known better. As an amateur gardener, I know the last frost of the year generally comes in April. However, I'm bombarded daily with the new truths about global warming. Just one month before our balmy March, the Intergovernmental Panel on Climate Change of the United Nations released its fourth global assessment, proclaiming for the first time that global warming is "unequivocal" and that human activity is the main driver.
"It is very likely that hot extremes, heat waves and heavy precipitation events will continue to become more frequent," stated the IPCC summary. Comprised of the top climate scientists in the world, this panel's findings are the best data available to us today.
So, knowing that global warming is predicted to bring higher temperatures, when warm weather hit, I figured the heat was here to stay and headed to the garden shop.
What was so dramatic about the April freeze was not so much the cold but that it followed such a warm week prior. Statistically, a typical April should provide highs around 70 and lows around 45 degrees. So, while freezing nights in early April are unusual, they aren't as unexpected as the unusually warm weather we experienced in March. And that's where global climate change comes into play.
Tennessee is certainly destined to make more moderate climate adjustments than the world's coldest areas or coastal communities will likely have to make, but scientific predictions say the state — and the nation — will experience higher temperatures overall throughout the year. And anecdotally speaking, the Midstate has experienced higher temperatures overall so far this year than we would have seen as kids several decades ago.
As we saw this spring, it doesn't take much change to cause a lot of damage. With warmer temperatures in March, plants bloomed earlier and were caught unawares in the April freeze.
As temperature extremes become more commonplace, plant and animal species already living on the fringes — those that are threatened, endangered or living on the outer boundaries of their natural habitat — will be the most affected. Non-native plants, such as honeysuckle and kudzu, which are hardy survivors in the Midstate climate to begin with, may become even more invasive, crowding out native species.
In addition, precipitation is predicted to begin clustering into more extreme weather events — more frequent and more intense storms, more springtime flooding and more long, dry summers, with the associated water shortages and droughts.
So what's the key to surviving a future of more extreme weather and higher temperatures? We will have to expect the unexpected and learn to adapt to weather unlike that we grew up with. One key will be better planning for those unexpected events, with better flood control as well as better water conservation.
And my garden shop will have to start stocking more plants and flowers that can adapt to the new climate along with us.
Source: The Tennessean©2007