The point of the article was that apparently no one had considered or measured the effects of jet contrails on surface temperatures (think global warming science).
Now I did not discover this, it merely reported the results originally discussed on the BBC program Horizon. Researchers had figured contrails matter but were unable to prove this until 9/11 here in the USA when all commercial jets were grounded for several days.
So, merely ten years later, climate researchers are now looking into this issue (see this article Science Codex). From Science Codex:
The researchers report that the "diurnal temperature range was statistically significantly reduced at outbreak stations versus non-outbreak stations." In the South, this amounted to about a 6 degree Fahrenheit reduction in daily temperature range, while in the Midwest, there was about a 5 degree Fahrenheit reduction. Temperatures the days before and after the outbreaks did not show this effect, indicating that the lower temperatures were due to the contrail outbreaks.
"Weather forecasting of daytime highs and lows do not include contrails," said Carleton. "If they were included in areas of contrail outbreaks, they would improve the temperature forecasts."
The underlined part (my underline) is quite interesting.
I my experience daily weather forecasting is, at best, abysmally unreliable. One has to believe that 6 degrees is quite a bit to miss out on (see this and this as well).
I wonder what impact this has had on the various temperature stations used, at least in the US?