A little over a year ago, as I was catching the local weather forecast, the young woman presenting started with a bit of news. The National Weather Service had just updated the “Climate Normal” data showing that Tucson’s average temperatures were now two degrees warmer than the past thirty years. She added, “This change tells us that our ecosystems and the kinds of plants and animals we see here are likely going to change.” Then she went on with the local weather, as if such a thing were just normal. And unfortunately, maybe she’s right.
Climate Normals are updated every ten years. “Normal” is defined as the 30-year average. For example, the average temperature normal in January for Phoenix is computed by taking the average of the 30 January values of monthly averaged temperatures from 1991 to 2020. Below, you can see the change in 30-year Climate Normals starting with 1901-1930. Overall, you can see that most of the country has warmed by 1.5 to 2 degrees.
That may not seem like much, but, as my weather girl noted, things are changing in the natural world. A recent study using 100-year-old museum collection of bird eggs found that, as a result of climate change, birds are laying their eggs a month earlier. They found that the amount of carbon dioxide in the atmosphere over time neatly maps onto larger temperature trends. The researchers found that it also correlated with the changes in egg-laying dates and to changes in when different plants bloom and insects emerge. Birds had changed their laying times to adapt to their food sources.
And while birds laying their eggs a few weeks early might seem like a small matter in the grand scheme of things, lead author John Bates notes that it’s part of a larger story. “The birds in our study area, upwards of 150 species, all have different evolutionary histories and different breeding biology so it’s all about the details. These changes in nesting dates might result in them competing for food and resources in a way that they didn’t used to,” he says.
These changes aren’t just going to affect the birds. It’s affecting agriculture too. For example, the 100th meridian, is one of the strongest natural boundaries in the world, marking the switch between the non-irrigated east and the irrigation-necessary west. Today, that boundary is no longer on the 100th meridian, but has shifted 140 miles to the east. Land use hasn’t yet been affected because the changes are still very small and gradual. But Richard Seager of the Earth Observatory theorizes that as drying progresses, farms in the east may have to consolidate, irrigate, or change the crops they raise. He even sees the possibility that cropland will be converted back to pasture and western-style grazing. Scientists further predict that the current climate change trajectory will make the U.S. Corn Belt unsuitable for cultivating corn by 2100.
None of this sounds like good news, but just as I get all this kind of information in my news feed, I also get stories about potential solutions like…scientists are working hard on developing plant varieties that do well in a warmer future, with this wheat cultivar as just one example. They’re looking at how and where we can successfully grow food and at a whole variety of ways to draw more carbon from the atmosphere with technology and through agriculture itself.
Things are going to change – and hopefully, like the birds, we can change too. It really seems like our only option.
Thanks for reading!
Kathy
