Josh Apte
joshapte.bsky.social
Josh Apte
@joshapte.bsky.social
Professor of Environmental Engineering + Environmental Health Sciences, UC Berkeley.

Research: air pollution, health, climate, EJ.
Reposted by Josh Apte
Shutting down the Energy Star program will raise your energy costs and make you sicker. There is no good policy reason to shut it down. None. It saves people lots of money and helps cut pollution. www.nytimes.com/2025/05/06/c...
E.P.A. Plans to Shut Down the Energy Star Program
www.nytimes.com
May 7, 2025 at 12:27 AM
Reposted by Josh Apte
Global science is not going to end at the whims of some ideology. More than 17,000 Earth and space scientists are gathering at #EGU25, including many from the U.S. www.egu25.eu
April 28, 2025 at 1:10 PM
I took advantage of the spring weather to sneak in a little hike in the Viennese Alps this morning before the start of #EGU25.

Awesome to see this old smokestack being repurposed for solar energy.

A nice metaphor for the change we need!
April 27, 2025 at 8:21 PM
Reposted by Josh Apte
PhD Timeline xkcd.com/3081
April 25, 2025 at 3:32 PM
Reposted by Josh Apte
NIH-supported Environmental Health Perspectives is the open-access flagship journal in environmental health. They have paused all new manuscript submissions "due to changes in operational resources". Is this the transparency and open discourse we were promised?

ehp.niehs.nih.gov/do/10.5555/b...
EHP Publishing
ehp.niehs.nih.gov
April 23, 2025 at 7:47 PM
Postscript: the 40-year old diesel locomotives are now retired, but they are not at the end of the line quite yet. Many will be exported to Peru soon to start a new commuter service.
April 16, 2025 at 4:15 PM
Bottom line: electrification can bring huge air quality benefits to rail systems and the communities they run through.

We have dozens of other commuter rail systems that still use mostly older diesel locomotives. We should electrify them ASAP.
April 16, 2025 at 4:15 PM
The reduction in black carbon at the SF station was so large that we saw the same drop in BC as what California cities achieved from *30 years* of clean air regulation!
April 16, 2025 at 4:15 PM
Over the 6 weeks of the electric transition, there was a clear correlation between days with fewer diesel locomotives idling and days with better air quality near the SF station.

Once the diesel locomotives were retired, we found almost no detectable increment in diesel smoke near the station.
April 16, 2025 at 4:15 PM
So, we equipped the SF Caltrain station with instrumentation to detect how much diesel smoke was coming from the locomotives.
April 16, 2025 at 4:15 PM
Before electrification, the SF Caltrain station was noisy and smoky at nearly any hour of day.

Why? An arcane safety regulation requires that locomotives have a careful safety inspection if they are shut down for too long. So, they usually were just left running.
April 16, 2025 at 4:15 PM
On diesel trains, smoke would blow straight into the passenger cars. Concentrations of black carbon were nearly as high as what I have measured in New Delhi traffic.

Electric trains were almost 90% cleaner on board!

This brings a meaningful reduction in cancer risk for staff & regular riders.
April 16, 2025 at 4:15 PM
We tracked concentrations of black carbon (BC) on-board dozens of diesel and electric trains.

BC is an excellent marker for diesel particulate matter, which is the #1 airborne carcinogen in California.
April 16, 2025 at 4:15 PM
Caltrain used to operate a fleet of 40-year old diesel-powered trains. Over 6 weeks last summer, these locomotives were swapped for sleek new electric trains.

The rapid transition made it easy for us to quantify the big air quality benefits.
April 16, 2025 at 4:15 PM
Most rail services in the US still use polluting diesel locomotives. Recently, our commuter rail system in San Francisco, @caltrain.com, was electrified.

Good news: we found DRAMATIC air quality improvements once the electric trains replaced the diesels.

pubs.acs.org/doi/10.1021/...
Dramatic Air Quality Improvements after the Complete Electrification of a Commuter Rail System
To limit the impact of climate change, there is an urgent requirement for infrastructure decarbonization and a transition to lower-emission energy systems. This is expected to result in local air qual...
pubs.acs.org
April 16, 2025 at 4:15 PM
Hey everyone, nice to be back online here at Bluesky.

I love how fresh and earnest this place feels - reminds me of the good old days.
April 16, 2025 at 5:58 AM