Global nitrogen dioxide levels dropped since COVID: NASA video | Hacker News Reader

Global nitrogen dioxide levels dropped since COVID: NASA video

mercedsunstar.com

46 pointsSCAQTony25 comments

I feel a little sad when I hear about the end of the pandemic.

I get that sounds bad initially, but ultimately, we just want to get right back to where we were before, needlessly flying everywhere, aimlessly driving around, polluting the Earth.

Hopefully we’ve learned something from this time!

In Vancouver, Canada, there was a quiet period in March and into April, with fewer cars on the road. Then through the summer it picked up, and the streets are now incredibly congested throughout the day. More people are driving everywhere to avoid public transit, and possibly out of boredom. It's very frustrating. I hardly go anywhere at all, working from home and all, but when I need to drive somewhere, like to a distant appointment in the middle of a weekday afternoon, there are cars, cars, cars everywhere.

As the old saying goes: You aren’t stuck in traffic, you are traffic.

For day to day driving, that's a useful thing to think about.

When someone is saying that they drive far less than before, but traffic is roundly awful when they do have to drive, that saying isn't insightful. There's a specific group you can focus on as causing the problem, not merely a tragedy of the commons.

It'll be a relief to be able to be around random people again when it's safe to do so, but the reduction in driving (both for myself, and having less traffic) was nice. The "less traffic" part doesn't really seem to be holding up though.

It's a bit encouraging to see what seemingly-impossible things people can accomplish when working together. We've done a lot more than anyone was planning to do to address climate change this year without that even being a primary motivation. Maybe that will recalibrate some expectations about what is possible.

The effects of COVID-19 and lockdown will increase emissions, not decrease. What we're seeing is migration out of cities, full of dense, energy efficient, apartment buildings, served by public transit, to suburbs and towns, full of low-density, energy intensive, housing, with just cars for transportation.

SF and NYC for example appear to have already lost 10%-20% of their population. Even where I live - a dense but fairly affordable neighborhood, in a third-tier city - tons of people are moving out. Meanwhile there's a property boom in previously undesirable low-density markets in the middle of nowhere: https://financialpost.com/real-estate/how-the-pandemic-lit-t...

Flying is just 9% or so of transportation emissions, and much of that is freight; personal vehicles account for around 50%. And residential buildings already account for significantly more energy use than commercial: 12% vs 8% of all energy used in Canada: https://www.nrcan.gc.ca/science-data/data-analysis/energy-da...

Finally, don't forget about habitat loss: all these people will want housing, turning yet more strain of our remaining wilderness and farmland into socially distanced suburbs.

While a lot of people have moved out of metro areas, I don't think many have done so permanently. Why spend 1000s on a small apartment in the city all alone when you could ride out the pandemic at your parents' in a large suburban home?

Maybe some people with families already may choose to stay in their new suburb. But young people will come back. Why? Because a large city is one of the best places to look for a partner. Or put more succinctly, people want to fuck. It might take a while for more young people to flood in, and in the meantime rent prices might dip, but I'm confident people will want to keep fucking in the future. So as long as that's there, I think cities will recover :)

That's a strange way of looking at things in the age of Tinder. In other words, you do not need to live in the city in order to be in the city every now and then. Those who have found out they can enjoy the positive aspects of cities without having to endure the negative ones will be hard-pressed to voluntarily subject themselves to a life of high rent and high crime, all in order to get laid when they realise they can get the latter without having to endure the former.

> Flying is just 9% or so of transportation emissions

Got to be wary of statistics. Last I checked (a few years ago) international shipping and aviation were not being accounted for very well, If at all.

For some reason countries do not want to add those figures to their domestic totals.

Edit: Not to take away from your assertion, which I agree with. The effects of the pandemic will not be unmixed environmentally. In the green corner: telecommuting and increased use of delivery services. In the brown corner: increased vehicle use and residential energy use from living in low-density areas.

1. From 2012 (time flies...): https://assets.publishing.service.gov.uk/government/uploads/...

Have you ever been to the USA? Only a tiny, tiny percent of percent of people are served by public transit. I'm also skeptical that the average apartment building is more energy efficient than suburban housing, since the incentive of the owner (who doesn't want to pay for energy-efficient upgrades and repairs) are not aligned with the renter (who pays the monthly utilities bill).

Does a rural/suburban driver spending 30 minutes driving on a highway produce more pollution than an urban driver spending 30 minutes in congested variable speed streets?

https://www.pewresearch.org/fact-tank/2016/04/07/who-relies-...

"City dwellers are also more frequent users of mass transit. Some 21% of urban residents use public transit on a regular basis, compared with 6% of suburban residents and just 3% of rural residents."

People are moving out of the cities, not suburbs, so this will have a very direct impact.

> I'm also skeptical that the average apartment building is more energy efficient than suburban housing, since the incentive of the owner (who doesn't want to pay for energy-efficient upgrades and repairs) are not aligned with the renter (who pays the monthly utilities bill).

The bulk of the emissions is generated by heating and cooling, and the former is the one with the most economies of scale. Around here, heating and hot water is usually paid for by the landlord in apartments (65% and 67% based on listings I just checked). That's not surprising: the way heating is provided is most commonly via hot water boilers, which don't make sense to provide on a per-unit basis.

Anyway, it's just basic physics: apartment units have much less surface area to radiate or absorb heat compared to individual houses. Takes much less energy to keep an apartment with just one exposed wall warm or cool than a house with 4 exposed walls and a roof.

Here's another source on this: http://www.frpo.org/wp-content/uploads/2015/04/2012-Apartmen...

3x less energy usage per resident for apartments vs single-occupancy detached homes.

> Does a rural/suburban driver spending 30 minutes driving on a highway produce more pollution than an urban driver spending 30 minutes in congested variable speed streets?

Absolutely yes. Energy usage is a function of speed, because the energy goes to overcoming air resistance. The scaling of velocity to energy usage is about v^3. Also, as the link I provided above shows, commutes are much longer - and public transit usage much less - for detached homes vs apartments.

The only reason planes make sense is they can fly so high that air resistance is lower.

> Only a tiny, tiny percent of percent of people are served by public transit.

US urbanized population is 5x its rural population. NY metro area alone is >5% of US population. In fact a significant percentage of Americans are served by public transit.

They often choose not to use it for a number of reasons, including poor physical fitness and train/bus being de facto homeless shelters/mental hospitals.

The lower overall carbon footprint of urbanized living is a well established fact. Goods needs to travel a shorter distance to reach consumers and vice versa. Infrastructure like plumbing, electricity, and heating is more efficient when providing for a million people living in a dense city than dispersed throughout the countryside.

> Does a rural/suburban driver spending 30 minutes driving on a highway produce more pollution than an urban driver spending 30 minutes in congested variable speed streets?

Yes, overwhelmingly yes. Commuter vehicles burn about 0.2 to 0.4 gallons per hour when idling. A car that gets 30 miles per gallon will burn 2 gallons per hour when driving on the highway at 60 mph. https://www.energy.gov/eere/vehicles/fact-861-february-23-20...

That's a bit naive view - people sitting at home in misery didn't do a squat re car/travel pollution. Massive container ships output much more, and what did everybody? Switch even more to internet deliveries, be it food or everything else. Unless its produced locally it comes from far.

Bigger effect would be shutting of factories, but then again we're talking about millions of blue collar workers getting potentially into serious financial problems with little help - hardly something to cheer up for.

To have any visible effect from transport on environment we would have to be stuck at home for maybe 20 years.

Ocean freight has far lower emissions per tonne/km than road, rail, or air transport[0].

[0] https://www.eea.europa.eu/data-and-maps/indicators/specific-...

They're probably thinking of

> just 15 of the biggest ships emit more of the noxious oxides of nitrogen and sulphur than all the world’s cars put together.

ESA's Sentinel program has also an NO2 map available where you can see the immediate effect of the lockdown across Europe. [1]

[1] https://maps.s5p-pal.com/

It's tempting to say "yay, there was some silver lining behind the pandemic", but a growing/recovering economy will easily pollute much more to catch up (look at India and China for example during pre-COVID times).

Even if that wasn't to happen, the only thing we successfully did was delay the problem. There is no shortcut. We need to encourage change from the bottom, all the way to the top. Ideally it shouldn't have a drastic impact on daily life.

I think given the diverse and mostly intelligent crowd here on HN it should be possible to really look at creating proper solutions that drive real change. It doesn't even need to be revolutionary, you can start today by cutting down on waste, find efficiencies in your work, switching to sustainable resources, etc. The little things add up.

its too late

were ded

I read the title as “watch a NASA video that shows a dangerous air pollutant being dropped on us during COVID”

Wouldn't surprise me.

De-clickbait: NO2 is the pollutant.

It was too dangerous to include in the title even!

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