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We Just Breached the 410 PPM Threshold for CO2

scientificamerican.com

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Re: We Just Breached the 410 PPM Threshold for CO2

#31

Post by cardamomo »

gjm11 wrote: post #12

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…

How we communicate climate science and its relevance to our world is just as important as the science itself. In my opinion, if labeling it a threshold in media intended for non-scientist audiences captures attention and calls readers to action, great! Frankly, we need to be "overexcited" about CO2 and stop sitting on our assess.

Re: We Just Breached the 410 PPM Threshold for CO2

#32

Post by mirimir »

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…

Sure, CO2 levels and temperature were a lot higher, 50 million years ago. But the problem for people is that global climate change will mess with stuff that we depend on. Such as the existence of major port cities. And growing food. And more generally, other species can't adapt as fast as our culture could. So we're looking at a major mass extinction. Which we'll also need to deal with, to the extent that we depend on disappearing species.

And sure, we could inject sulfur oxides into the stratosphere. That would create haze that would reflect sunlight. And it wouldn't wash out very quickly. There would still be some acid precipitation impacts, but probably not as bad as we saw in the 60s. However, that would be a huge endeavor, and would take considerable energy.

Re: We Just Breached the 410 PPM Threshold for CO2

#33

Post by Sharlin »

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.

"Fine" in the sense that life survived the previous extinction events too. In the sense that Europe was "fine" after the world wars.

Re: We Just Breached the 410 PPM Threshold for CO2

#34

Post by yongjik »

shouldbworking wrote: post #30
JshWright wrote: post #15

Earlier quoted context omitted.

> 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 s…

I see your point. To me it's like numerous engineers are warning me that the temperature of the building is going up quickly. When I ask any of them what to do they say we should stop producing heat. I ask whats going to happen when the building gets hotter quickly and get 10 different answers. Somebody tells me the building has been much hotter in the past, but this is the fastest its heated up before. I ask if it's…

I have to admire the audacity of people arguing "The Earth has been hotter several million years ago," as if that's relevant at all.

If a storm cuts off gas, electricity, water, internet, and paved road access to these people, and the government says "What's the problem? People have been living without them for most of history!", these same people would cry bloody murder (as anybody else would).

Re: We Just Breached the 410 PPM Threshold for CO2

#35

Post by shouldbworking »

mirimir wrote: post #32
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…

Sure, CO2 levels and temperature were a lot higher, 50 million years ago. But the problem for people is that global climate change will mess with stuff that we depend on. Such as the existence of major port cities. And growing food. And more generally, other species can't adapt as fast as our culture could. So we're looking at a major mass extinction. Which we'll also need to deal with, to the extent that we depend o…

So far the biggest effect of higher CO2 levels seems to be increased foilage and crop yields http://onlinelibrary.wiley.com/doi/10.1002/grl.50563/abstrac...

I don't see how this would be expected to reverse when concentrations continue to rise

Re: We Just Breached the 410 PPM Threshold for CO2

#36

Post by rwmj »

shouldbworking wrote: post #30
JshWright wrote: post #15

Earlier quoted context omitted.

> 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 s…

I see your point. To me it's like numerous engineers are warning me that the temperature of the building is going up quickly. When I ask any of them what to do they say we should stop producing heat. I ask whats going to happen when the building gets hotter quickly and get 10 different answers. Somebody tells me the building has been much hotter in the past, but this is the fastest its heated up before. I ask if it's…

I think the problem is it's bad for humans on Earth, not that it's bad for life on Earth in the long run. For sure if all humans died off, all non-human life would be much better off.

Re: We Just Breached the 410 PPM Threshold for CO2

#37

Post by JshWright »

shouldbworking wrote: post #30
JshWright wrote: post #15

Earlier quoted context omitted.

> 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 s…

I see your point. To me it's like numerous engineers are warning me that the temperature of the building is going up quickly. When I ask any of them what to do they say we should stop producing heat. I ask whats going to happen when the building gets hotter quickly and get 10 different answers. Somebody tells me the building has been much hotter in the past, but this is the fastest its heated up before. I ask if it's…

I think you're stretching the analogy a bit too far there...

We know that increasing atmospheric levels of CO2 will result in higher temperatures (the mechanism is well understood, and the IPCC models have done a good job of predicting that over the past couple decades), we also know rising temperatures will result in rising sea levels (again, we have empirically observed this happening at rates consistent with our understanding of the mechanism). From there it's just math to figure out how much coastal land will be inundated over the coming century (which is just one of many implications of climate change).

You are suggesting various ways in which that might not happen, with no evidence supporting them, from the perspective of someone who doesn't have much of an understanding of climate science. Do you think it is more likely that you have outsmarted 97% of climate scientists, or that the experts are more likely to know what they're talking about than you are?

Re: We Just Breached the 410 PPM Threshold for CO2

#38

Post by codecamper »

gjm11 wrote: post #12

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…

Agreed. It's time to get very very excited here. Well if you only care about yourself, then screw it. If you have an ounce of care for the next generation or the ecosystems of the Earth, then it's time to start doing everything possible to replace our power generation with renewables (solar & wind) and our cars with electric cars.

It won't cost all that much. Not doing it will cost a whole heck of a lot more.

Re: We Just Breached the 410 PPM Threshold for CO2

#39

Post by ythn »

lurker456 wrote: post #27
ythn wrote: post #21

Earlier quoted context omitted.

Not quite the same. Climate scientists are notoriously bad at predicting consequences of climate change - kind of like how meteorologists are often bad at predicting the weather. Why is it okay to be skeptical of what meteorologists are predicting, but not okay to be skeptical of what climate scientists are predicting? It's one thing to be skeptical of sciences that have stood the test of time like civil engineering…

That's akin to demanding that all engineers accurately predict which piece of the roof will collapse first, where the pieces will hit the floor, how many pieces it will break up into and on which date. The overwhelming consensus of experts is that its going to have an enormous impact. It's still worth studying when, how and where its effects will materialize first but that does not excuse inaction.

> The overwhelming consensus of experts is that its going to have an enormous impact.

How soon? Al Gore's "An Inconvenient Truth" predicted apocalyptic consequences in as few as 10 years. 10 years later and it turns out the documentary had tons of erroneous assumptions. Oops.

> That's akin to demanding that all engineers accurately predict which piece of the roof will collapse first, where the pieces will hit the floor, how many pieces it will break up into and on which date.

If your model has poor predictive power, it's not a complete model. Engineers can accurately predict lots of things using standard models - for example whether a building will be able to withstand shear wind forces. Climate science cannot predict anything except "it will be disastrous with apocalyptic proportions at some non-deterministic point in the future" How is that a useful prediction beyond generating hype?

Re: We Just Breached the 410 PPM Threshold for CO2

#40

Post by anigbrowl »

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…

On a species level we'll probably survive it, but that doesn't mean it won't be disastrous at the individual level. Suppose, for example, that a natural disaster reduces the human population by 50$ over a few decades. Humanity survives, but the deaths of 3-4 billion people would be pretty awful.
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