Does Artificial Light Impact Autumn Foliage Timing? - Initial Research Says Yes.

This month, I had some really insightful conversations with Dark Sky Consulting’s John Barentine and ecologist, Lin Meng. I was also joined by remote sensing researcher Zhe Zhu for the first show this month. We had some great conversations this month. Be sure to check out Solar Days and Lighting for Reassurance! As always, you can find all of the links to this show and beyond over at LightPollutionNews.com. Light Pollution News is a listeners supported show, which means that all of the work here is solely fueled by supporters like yourself. If you like what we’re doing, please consider sharing this update.

So let’s jump into it! Did you hear about the Sunshine Protection Act of 2025? I’m sure you did, but were you aware that it was not only reintroduced this summer, but it breezed through the House on July 14^th. The bill seeks to enshrine permanent Daylight Saving Time under the sponsorship of two Florida Representatives: House Rep Vern Buchanan and Senator Rick Scott.

However, the bill stalled in the Senate. An interesting twist came in how places like Disney World and Universal, which built entire event seasons around darkness, would be affected by losing one hour of night. Permanent DST would leave those parks with 2 ½ hours of usable nighttime programming. Conversely, the American Academy of Sleep Medicine backed the other solution, a permanent Standard Time under the competing, and no less sappy sounding, Sunshine for Our Kids Act. Science appears to be in alignment that Standard Time is healthier than permanent Daylight Saving Time. The US tried permanent DST in 1974, loved it initially, then reversed course within ten months when northern states suffered through 9 AM sunrises. Oof!

In the wonderful world of ecology, of which we have a tremendous amount but were only able to cover select stories this month, Dr. Meng’s team found areas with artificial light correlated with pollen seasons starting 20 days earlier and running significantly longer (See all of our Ecology News). In light polluted areas, it was found that 27% of the pollen season days tended to be severe, versus 17% in areas with low levels of satellite measured light pollution. In a separate study looking at nighttime pollination on the Tibetan Plateau it was found that moth driven pollination activity dropped nearly 50% under artificial light, reducing seed maturation by 56%.

On the policy front, Breckenridge began enforcement of its lighting ordinance in January of this year. However, the cost to upgrade has become a source of consternation. One business owner spent $8,000 upgrading its lighting to compliance. The most notable complaint involved simply finding the right fixture. Consumer hardware stores, perhaps unsurprisingly, proved of little help. Breckenridge adopted its lighting ordinance in 2007 and had a very generous 15-year runway to comply.

Elsewhere, Kentucky's House Bill 571 took effect on July 15th, requiring shielding on highway lights near farmland. Rockport, Massachusetts declined free LED lighting from energy provider, National Grid that would have saved $40k annually. Rockport voted 823 to 82 to keep high pressure sodium lighting over the more efficient and cheaper operating LED fixtures.

Dr. Meng also discussed her team’s new exploratory study looking to see if there was enough data to assess whether lighting policies had effect on communities. They looked at two pairs of cities: New York City and Newark, New Jersey; and Philadelphia and Washington, DC. New York and DC both had lighting policies on the books,while Newark and Philadelphia lacked any responsible lighting codes. Their exploratory study found that city lighting laws worked. Cities with policies saw spring leafing delayed 4 days and autumn color arriving 7 to 9 days earlier, signaling shorter, less disrupted growing seasons. It should be noted that the research here is very preliminary.

In satellite news, Dark Sky International, Environmental America, and Public Employees for Environmental Responsibility petitioned the FCC on July 8th for environmental reviews on planned orbital data center constellations. Separately, SpaceX disposed of 260 Starlinks in six months via atmospheric reentry and executed 355,000 collision avoidance maneuvers in the past year.

On the health front, a study of 222 schizophrenia outpatients found those in the brightest bedroom settings showed 4x higher odds of obesity, 3.4x higher odds of hypertension, and carried 22lbs more body weight.

In the auto world, do you think headlights were too bright? Well, you are right! Tesla exceeded legal headlight brightness by double the lumens on 20,000 vehicles, argued no one complained so it must be fine, and lost that argument two years later. GM tried the same for 725,000 SUVs. GM also failed.

On the culture front, we closed out this month with a discussion on Guy Ottewell, who published his Astronomical Calendar for 43 consecutive years and received an asteroid named in his honor on July 6th. Also, did you know that there’s essentially an American Stonehenge? Artist Charles Ross spent decades building Star Axis in New Mexico. The facility is aligned to astronomical calculations in the tradition of Stonehenge.