We Just Breached the 410 PPM Threshold for CO2 • Hacker News Board

Re: We Just Breached the 410 PPM Threshold for CO2

#11

Post by shouldbworking » Sat, Apr 22, 2017, 8:30 PM UTC

DiThi wrote: post #6

shouldbworking wrote: post #4

I don't know much about climate science, but won't plants multiply and grow faster until we eventually hit a new equilibrium CO2 level? I guess the only danger is reaching thermal runaway before that happens? Then again, earth CO2 levels have been far higher in the past without signs that it killed off much life on Earth. Is rising CO2 that dangerous? Don't humans already have effective ways to reduce surface heating…

Life on Earth will be fine. The problem is the survival of our own species. It heavily relied in ~15,000 years of stable climate to flourish, and we're cutting that stability short.

One thing I thought about a while back related to this. Predictions show that increased energy in the atmosphere results in stronger storms. Storms are not preserved in the historical record, so how bad will they be? The relationships between temperature and energy tend to be supralinear...

Has anyone looked at common species from warm earth periods to predict storm severity? I remember reading that palm-like trees used to be the dominant type. These trees still are in island areas mostly because they are extremely resistant to storms. They have few leaves and thick trunks.

Are we setting ourselves up for a future where average wind speeds are 5x higher and hurricane-like storms devastate the landscape every year or so?

Re: We Just Breached the 410 PPM Threshold for CO2

#12

Post by gjm11 » Sat, Apr 22, 2017, 8:31 PM UTC

This is very bad (albeit completely unsurprising) news, but I really don't see that the word "threshold" is appropriate. Is there some special bad thing that happens once 410ppm is reached, that's qualitatively different from 400ppm? Nope.

The article itself is quite clear about this: e.g., it quotes one climate scientist as saying "These milestones are just numbers, but they give us an opportunity to pause and take stock and act as useful yard sticks for comparisons to the geological record." I suspect it's the usual story: journalist writes reasonable article, sub-editor puts needlessly overexcited headline on it.

Re: We Just Breached the 410 PPM Threshold for CO2

#13

Post by shouldbworking » Sat, Apr 22, 2017, 8:33 PM UTC

mikeash wrote: post #9

shouldbworking wrote: post #4

I don't know much about climate science, but won't plants multiply and grow faster until we eventually hit a new equilibrium CO2 level? I guess the only danger is reaching thermal runaway before that happens? Then again, earth CO2 levels have been far higher in the past without signs that it killed off much life on Earth. Is rising CO2 that dangerous? Don't humans already have effective ways to reduce surface heating…

Increasing CO2 does not necessarily result in more plants. The feedback cycles are complex and there are other limiting factors. Imagine, for example, if the oxygen concentration was increasing instead. Would you expect humans to multiply faster and reach a new equilibrium because of it? Concentrations have indeed been much higher in the deep past. The concern isn't destroying all life, it's damaging or destroying ci…

I read that the era of nuclear testing noticably decreased surface temperatures for some time. If we can't figure anything else out we could probably settle for blowing up a bunch of cleanish lead wrapped nukes out in the ocean every couple months? It sounds terrible but if done right it would have little impact to life on earth

Re: We Just Breached the 410 PPM Threshold for CO2

#14

Post by mturmon » Sat, Apr 22, 2017, 8:33 PM UTC

tajen wrote: post #3

How do we measure the average concentration of CO2 in the atmosphere, given all the disparity and local extremums?

The article describes an in situ (ground based) measurement, that is sample based.

You can get CO2 concentrations from satellite remote sensing, as well. Usually they use spectral analysis of CO2 emission/absorption lines in the infrared. This is a passive measurement, but active measurements with lasers are used in ground based and airborne measurements now.

These measurements are of CO2 within a given (vertical) column of air -- where the infrared light came from -- whereas the Mauna Loa measurement in TFA is localized to air moving past the sample station.

One starting place for CO2 data is: https://co2.jpl.nasa.gov

This summary of Los Angeles area ground based measurements hints at some of the complexities of integrating these different data sources: https://megacities.jpl.nasa.gov/portal/collection-network/ .

Other pages on that site indicate the extreme spatial and temporal variability of CO2 in an urban setting. That's why the comparatively pristine Mauna Loa site is so important.

Re: We Just Breached the 410 PPM Threshold for CO2

#15

Post by JshWright » Sat, Apr 22, 2017, 8:34 PM UTC

shouldbworking wrote: post #4

I don't know much about climate science, but won't plants multiply and grow faster until we eventually hit a new equilibrium CO2 level? I guess the only danger is reaching thermal runaway before that happens? Then again, earth CO2 levels have been far higher in the past without signs that it killed off much life on Earth. Is rising CO2 that dangerous? Don't humans already have effective ways to reduce surface heating…

> I don't know much about climate science ... I'm just skeptical that the rising CO2 level is as dangerous as it's made out to be.

Respectfully, is this a mindset you apply to other aspects of your life?

Let's say you leased an apartment in a large building, and after an inspection, numerous structural engineers said the building was in danger of collapse. Would you say "I don't know much about engineering, but I'm skeptical it's that bad", or would you demand the building management take steps to correct the issues?

Re: We Just Breached the 410 PPM Threshold for CO2

#16

Post by clumsysmurf » Sat, Apr 22, 2017, 8:34 PM UTC

shouldbworking wrote: post #4

I don't know much about climate science, but won't plants multiply and grow faster until we eventually hit a new equilibrium CO2 level? I guess the only danger is reaching thermal runaway before that happens? Then again, earth CO2 levels have been far higher in the past without signs that it killed off much life on Earth. Is rising CO2 that dangerous? Don't humans already have effective ways to reduce surface heating…

CO2 impacts more than plants. For example "Rising CO2 levels reduce protein in crucial pollen source for bees"

https://www.purdue.edu/newsroom/releases/2016/Q2/rising-co2-...

Re: We Just Breached the 410 PPM Threshold for CO2

#17

Post by mikeash » Sat, Apr 22, 2017, 8:36 PM UTC

shouldbworking wrote: post #13

mikeash wrote: post #9

Earlier quoted context omitted.

Increasing CO2 does not necessarily result in more plants. The feedback cycles are complex and there are other limiting factors. Imagine, for example, if the oxygen concentration was increasing instead. Would you expect humans to multiply faster and reach a new equilibrium because of it? Concentrations have indeed been much higher in the deep past. The concern isn't destroying all life, it's damaging or destroying ci…

I read that the era of nuclear testing noticably decreased surface temperatures for some time. If we can't figure anything else out we could probably settle for blowing up a bunch of cleanish lead wrapped nukes out in the ocean every couple months? It sounds terrible but if done right it would have little impact to life on earth

That seems unlikely. Nukes are pretty small on the scale of the earth. Things like plutonium concentration went up significantly because the natural level is so low, but I doubt they did much for aerosols.

A clean nuke detonated over the ocean would do nothing. The whole point would be to produce vast amounts of dust i.e. be dirty.

Re: We Just Breached the 410 PPM Threshold for CO2

#18

Post by denim_chicken » Sat, Apr 22, 2017, 8:37 PM UTC

shouldbworking wrote: post #4

I don't know much about climate science, but won't plants multiply and grow faster until we eventually hit a new equilibrium CO2 level? I guess the only danger is reaching thermal runaway before that happens? Then again, earth CO2 levels have been far higher in the past without signs that it killed off much life on Earth. Is rising CO2 that dangerous? Don't humans already have effective ways to reduce surface heating…

The current level of atmospheric CO2 is not unprecedented, but the current rate of change of atmospheric CO2 is. Couple that with massive ecological decimation and biodiversity due to human habitation and it is clear that our current predicament is geologically unprecedented.

Re: We Just Breached the 410 PPM Threshold for CO2

#19

Post by monk_e_boy » Sat, Apr 22, 2017, 8:39 PM UTC

shouldbworking wrote: post #13

mikeash wrote: post #9

Earlier quoted context omitted.

Increasing CO2 does not necessarily result in more plants. The feedback cycles are complex and there are other limiting factors. Imagine, for example, if the oxygen concentration was increasing instead. Would you expect humans to multiply faster and reach a new equilibrium because of it? Concentrations have indeed been much higher in the deep past. The concern isn't destroying all life, it's damaging or destroying ci…

I read that the era of nuclear testing noticably decreased surface temperatures for some time. If we can't figure anything else out we could probably settle for blowing up a bunch of cleanish lead wrapped nukes out in the ocean every couple months? It sounds terrible but if done right it would have little impact to life on earth

"The view that some scientists have that we need to manipulate the planet in order to fix it is another one that bothers me. We need to be wary of false solutions like geoengineering. I’ve just read a paper that outlines plans to pump cold water into the Arctic to try and refreeze the ice-cap. It’s totally mad! This old style of thinking believes the Earth operates like a machine, but that’s not how natural systems operate."

10 Things You’ve Always Wanted to Ask an Environmental Scientist -- https://medium.com/greenpeace/10-things-youve-always-wanted-...

Re: We Just Breached the 410 PPM Threshold for CO2

#20

Post by bsdetector » Sat, Apr 22, 2017, 8:40 PM UTC

I haven't seen any talk about the health effects of rising CO2.

I know there are studies finding a difference in productivity between 600 and 1000 ppm with just hours of exposure, so isn't it possible that going from 300 globally to over 400 has had some health impact over a lifetime? Is there a point where lower CO2 has no effect and how do we know that?