What's Really Warming the World? • Hacker News Board

Re: What's Really Warming the World?

#201

Post by tocf » Wed, Jun 24, 2015, 4:32 PM UTC

Shivetya wrote: post #20

CO2 is not strictly human emissions and to imply so is so dishonest is ridiculous. of course any gross simplification of the environment as done in this presentation is explicitly to deliver a message decided before the numbers were assembled. the primary co2 process is ocean to atmosphere exchange, the earth to atmosphere, and then to mammals respiratory activity. So then you get down to how much CO2 is man pumping…

> CO2 is not strictly human emissions and to imply so is so dishonest is ridiculous.

That was never implied. In fact, they made a point of comparing human driven emissions (which includes things like transportation and agriculture) to natural sources (eg volcanoes).

> the primary co2 process is ocean to atmosphere exchange, the earth to atmosphere, and then to mammals respiratory activity

Well, you're missing some stuff in there. Like plants n stuff.

> finally since their numbers only are observable to 1880, how accurate can we assume them to be?

This chart has data back to 1880. Ice core samples, tree rings, whole hosts of other parts of science go back much farther than 1880. All of it seems to corroborate each other.

> If were are extrapolating we could do it further back than 1880 to periods where man was present in significant numbers and thew world was warmer

> Take numbers out of context, put in easily to dismiss arguments along side, and it appears to make your point beyond reproach

Hm, sort of like simplifying the CO2 cycle to a few words, missing a bunch of it, and then somehow pretending to think that that explains things much better than hundreds of scientists who have given us the science that shows that this is mainly due to human causes.

Head up to the Arctic. Talk to people whose families have lived there forever and see for yourself. I think that's the only way to convince people like yourself.

Re: What's Really Warming the World?

#202

Post by chris_va » Wed, Jun 24, 2015, 4:32 PM UTC

dnautics wrote: post #132

fexl wrote: post #72

Earlier quoted context omitted.

Are there any data on water vapor concentrations? I ask that because I have read that the contribution of water vapor to the greenhouse effect is perhaps two to four times greater than CO2.

Not only that, all greenhouse models require a 'water feedback loop'. Of course there are plenty of anthropogenic water emissions to go about. When you irrigate, you are effectively throwing water into the air - by increasing the surface area of water evaporation through plant transpiration networks. I have never seen anyone talk about this alternative hypothesis. A disclaimer - I am all for reducing CO2 emissions st…

It's a reasonable question. While I am not a climatologist...

Anthropogenic evaporation is probably minuscule next to deviations in natural evaporation due to small changes in temperature. A single hurricane, for example, dumps more power (as heat) than all human power generation.

Also, unlike CO2, I would also guess that atmospheric water probably reaches equilibrium much faster (half life ~1 year instead of ~30 years).

Re: What's Really Warming the World?

#203

Post by ocschwar » Wed, Jun 24, 2015, 4:33 PM UTC

merpnderp wrote: post #169

ocschwar wrote: post #153

Earlier quoted context omitted.

They've not performed well based on criteria chosen by global warming denialists. For example, you'd be hard pressed to find a climate scientist making any solid predictions about annual global temperature averages. You will, however, see predictions about decadal averages, and those have borne out.

Borne out? Compared to what? The RSS and UAH 6.0 lower troposphere predictions? What other measurements do we have that don't have uncertainty bands as large as the measurements? And the zero trend from May 2015 extends back to 1996 for RSS and UAH 6.0.

That "zero trend" is only there if you use annual averages.

Again: use decadal moving averages, and an entirely different picture comes up.

Re: What's Really Warming the World?

#204

Post by snowwrestler » Wed, Jun 24, 2015, 4:34 PM UTC

fexl wrote: post #72

flavor8 wrote: post #22

Earlier quoted context omitted.

http://www.epa.gov/climatechange/science/indicators/ghg/ghg-... http://www.geocraft.com/WVFossils/last_400k_yrs.html http://www.sciencemag.org/content/339/6124/1198.abstract

Are there any data on water vapor concentrations? I ask that because I have read that the contribution of water vapor to the greenhouse effect is perhaps two to four times greater than CO2.

Water vapor is a much larger contributor to the greenhouse effect than CO2. There is a lot more of it in the atmosphere.

The reason water vapor cannot be a forcing (i.e. root cause) of global warming is because of how short the water cycle is. If the amount of water vapor in the atmosphere increases, it is rather quickly balanced back by fixing some of the water vapor into liquid water. We call this process "precipitation."

I've seen estimates that the length of the water cycle is on the order of a week or two. So if human activity puts a lot of extra water vapor into the air--say, with a nuclear power cooling tower--then the excess water vapor will precipitate back into the liquid water within a week or two.

Human society has adapted very well to this cycle. We have built our societies to manage rain and snow [1].

The carbon cycle is much longer--I've seen estimates on the order of several decades at least. Thus, if human activity puts an excess of CO2 into the atmosphere, that will be there for several decades or longer. Thus the effect has quite a bit longer to compound, producing changes that seem long-term to human societies.

We have not built our societies to adapt to the effects of these types of trends. Think of how many human structures within just a few meters elevation above mean sea level, for example. Like: most of Manhattan.

Water vapor is a feedback. If the average atmospheric temperature goes up (for any reason), it can hold more water vapor, which then further increases the greenhouse effect, which raises the temperature more, etc. One reason scientists build complex computer models is to figure out how a little bump in temperature (from CO2 for example) can be magnified by feedbacks like water vapor.

[1] Well, at least in the volumes that have been common over the past few hundred years.

Re: What's Really Warming the World?

#205

Post by merpnderp » Wed, Jun 24, 2015, 4:34 PM UTC

crimsonalucard wrote: post #36

This article only serves to stroke the ego of people who already believe that CO2 emissions cause global warming. It does nothing for people who already deny it. Evidence, no matter how strong doesn't serve to change the nature of a man. People would rather bend the logic and the evidence to fit their convenient perception of reality. Which brings me to the question: "What can change a nature of a man?" Imminent dang…

There's another option, keep using calm reason. For instance, run the troposphere trend back from May 2015 and you'll see it is flat to December 1996. UAH 6.0 and RSS are the best (most accurate, least problematic, with highest coverage) sources of atmospheric temperatures we have.

http://images.remss.com/msu/msu_time_series.html

Re: What's Really Warming the World?

#206

Post by ocschwar » Wed, Jun 24, 2015, 4:35 PM UTC

jcranmer wrote: post #127

moubarak wrote: post #4

i read an article a while back on the economist which suggested that if you look at a longer span (much longer than 1880) you will find that this is a natural cycle that the Earth/Sun go through. We just happen to be at that point in the cycle. i really doubt we humans can affect climate changes in any way. An interactive colourful plot doesn't convince me.

The anthropogenic component (this includes both industrial processes like Haber-Bosch and changes brought about by high-intensity farming) to most legs of the nitrogen cycle equals or exceeds that of the natural component. To argue that humanity is incapable of screwing with climate in any significant way when we are clearly overriding natural ecological cycles is pure inanity.

When talking about the "significance," we forget that we're talking about differences of 5K in an ambient temperature of 300K.

We're not "significantly" screwing with the climate. That's not the issue. The issue is just how sensitive our civilization is to such a small temperature change.

Re: What's Really Warming the World?

#207

Post by fexl » Wed, Jun 24, 2015, 4:36 PM UTC

hackuser wrote: post #195

fexl wrote: post #171

Earlier quoted context omitted.

I searched on the words "vapor" and "vapour" and found nothing. I also search on the word "water" and found nothing relevant to my question.

Perhaps the searches are [EDIT: not] looking in the PDFs? I just opened the Summary for Policymakers for the Physical Science Basis report, and found a few discussions of water vapor in the atmosphere. I'd try looking at "Physical Science Basis" and "Impacts, Adaptation and Vulnerability" reports; try the Summaries for Policymakers first, and the full reports if those don't have what you need (though go straight to t…

I opened the "Summary for Policymakers" listed right on their home page, and it popped up a PDF titled "AR5_SYR_FINAL_SPM-1.pdf". That's where I searched on the word "vapor" and found only one occurrence -- inside the word "evaporation".

I guess the "for the Physical Science Basis" report is something different that I haven't found yet.

Re: What's Really Warming the World?

#208

Post by chris_va » Wed, Jun 24, 2015, 4:36 PM UTC

fixermark wrote: post #158

fredkbloggs wrote: post #99

Earlier quoted context omitted.

It can't. The process is sufficiently slow that an individual, especially an older individual of the sort who make up legislatures and other influential institutions, can reasonably expect to die before it does him significant personal harm. Therefore it is fairly easy for such an individual, if given the proper incentives, to dismiss or deny it. As long as there are fossil fuels in the ground that can be extracted p…

Extinction is unlikely, given the vast amount of energy we have at our disposal (even if that energy's consumption is making it hard to be a biological construct on this earth). No, the likely scenario is in some ways even sadder: the 1% will survive in carefully-cultivated bunkers by the thousands or tens of thousands, and the vast majority (along with an awful lot of the other life on the planet) will die. Extincti…

That is not a likely scenario.

The projected net impact from global warming is on the ~$2T/year range.

That is about 3% of GWP. We aren't talking the end of the species, just really stupid expensive mistakes.

Re: What's Really Warming the World?

#209

Post by themartorana » Wed, Jun 24, 2015, 4:37 PM UTC

nsxwolf wrote: post #168

themartorana wrote: post #93

Earlier quoted context omitted.

This reminds me of Dick Cheney's stance on homosexuality. People will deny for myriad reasons, and are able to disassociate harm caused when that harm is borne by others. But the second it effects them? The tune changes quickly. We have deniers in our families. The reasons seem to be "I want to be salty" more than anything real. Edit: that said, I imagine most people behind Fox News and other right-wing news sources…

For every Dick Cheney there are probably a thousand parents who will ostracize or disown their gay children. And probably as many who will accept their children but don't change their views on homosexuality. I'm not sure if the left means to praise Dick Cheney for changing his mind on homosexuality, or mock him for changing his mind because he's a right winger.

Neither. It stands on its own, that the right's de facto behind-the-scenes leader doesn't get behind homosexual discrimination almost entirely because his daughter is gay. It's not praise or put-down - instead it's an example.

Parents disowning their gay children is almost entirely religious-based. The Dick Cheney example is one of pure politics, which is a prime example of where the discriminatory views from the right become equally disgusting to people on the right when they're the victims of said discrimination.

Re: What's Really Warming the World?

#210

Post by merpnderp » Wed, Jun 24, 2015, 4:37 PM UTC

ocschwar wrote: post #203

merpnderp wrote: post #169

Earlier quoted context omitted.

Borne out? Compared to what? The RSS and UAH 6.0 lower troposphere predictions? What other measurements do we have that don't have uncertainty bands as large as the measurements? And the zero trend from May 2015 extends back to 1996 for RSS and UAH 6.0.

That "zero trend" is only there if you use annual averages. Again: use decadal moving averages, and an entirely different picture comes up.

How do you use decadal moving averages from satellite data that has only existed since 1979? You'll get roughly the same trend as the full data set. Even so, the last two decades would still be flat, or very nearly so.