this post was submitted on 07 Feb 2024
37 points (95.1% liked)

Climate - truthful information about climate, related activism and politics.

5101 readers
551 users here now

Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world. About 1C of total warming. Second chart: about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability. Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases. About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

Anti-science, inactivism, and unsupported conspiracy theories are not ok here.

founded 1 year ago
MODERATORS
silence7@slrpnk.net
37
EVs won over US early adopters, but mainstream buyers aren't along for the ride yet (www.npr.org)
submitted 8 months ago* (last edited 8 months ago) by silence7@slrpnk.net to c/climate@slrpnk.net
49 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] Thevenin@beehaw.org 6 points 7 months ago* (last edited 7 months ago)

I'm gonna post this link to a former comment of mine, since this subject comes up a lot. Neither EVs nor public transit is a magic bullet.

The efficiency of public transit depends on ridership; nowhere in the world does it actually achieve 100% occupancy for more than a few minutes at a time, and nothing is more wasteful than a train running a circuit with only one passenger. At least by my calculations, it would take an average occupancy rate increase of 1.6x (for electric light rail) to 2.4x (for electric busses) over pre-pandemic levels for US public transit to reach parity with EVs, both in terms of electricity per passenger mile and tons of raw material per capita (such as steel, aluminum, copper, glass, and plastic). We'd need higher occupancy than the trains in Europe and the busses in Taiwan. Whether or not that's geographically possible in North America is an open question.

Ebikes are great, no question there, but thanks to parasitic drain in cheap chargers, they use 1/3rd the energy a typical EV does (kWh per passenger-mile, adjusted for occupancy but not speed), when they should use only 1/10th. That's a problem I expect to see solved in the next year or so, but it's a great reminder that nothing runs on magic.

As I say in the linked comment, public transit has critical advantages in the fields of urbanism and human-centric city design. I like trains and busses, and I vote for them every chance I get, it just bothers me when people conflate these advantages with environmental impact.