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What's Really Warming the World?

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Re: What's Really Warming the World?

#141

Post by mangeletti »

bharath28 wrote: post #130
mangeletti wrote: post #112

The chart at http://d1vn86fw4xmcz1.cloudfront.net/content/royptb/363/1501... (put together by The Royal Society) shows that most deforestation in Eastern Canada occurred over 400 years ago. This one http://mongabay-images.s3.amazonaws.com/12/1203all-time-defo... shows a shift starting about 300 years ago from temperate forest removal to tropical forest removal. Together, they start to paint a picture of massive defor…

I didn't read the whole paper (where that graph came from), so my apologies if i am misstating anything. It appears that the paper is focused mostly on the forests in Eastern Canada. At first glance, I'd find the slope on that graph (last 500 years) very hard to believe if it were for all of planet earth.

I've updated my comment to add another chart. The chart was intended to reflect the relative rate of deforestation, but the second one does a better job, and is even more alarming.

Re: What's Really Warming the World?

#142

Post by primroot »

andyjohnson0 wrote: post #48
_petronius wrote: post #37

Earlier quoted context omitted.

I think in the context of convincing people that we urgently need to address the current climate problem (for economic, ecological, and security reasons), that might be distracting. Assuming there are probably other interglacial periods in Earth's long history that were a lot warmer than the current one[0], or maybe had lots more greenhouse gasses from some non-human source (if such a thing is geologically possible),…

"...the Earth has had worse ecological disasters than the human species..." True, but they were a long time ago and the human species wasn't around to experience them. The rate of change of present warming, and its likely effects, are going to cause very severe difficulties for our (and many other) species.

I would replace "are causing" for "are going to cause." One of may examples: https://en.wikipedia.org/wiki/Ocean_acidification

Re: What's Really Warming the World?

#143

Post by hackuser »

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.

A lot of this is answered in the IPCC reports, which have readable, short summaries:

https://news.ycombinator.com/item?id=9772353

Re: What's Really Warming the World?

#144

Post by vilda »

macinjosh wrote: post #83

Please don't take this as a denial of climate change, it is an honest question. How do scientists learn the levels of ozone, aerosols, green house gases, and the other data points going so far back at a global scale? Is the data from before the latter half of the 20th century spotty? If so, why is it considered good enough to use in a context of scientific research where quality and correctness of data is paramount?

They use so-called "proxy data". You measure something else that has been accumulated and preserved over time and that somehow correlates. You have to create a model, fit it so it correlates with recent measures and you are done.

Level of oxygen for example can be estimated from layers of ice. Mann used tree slice(s) for temperature estimation.

There's a lot of problems with proxy data and their models and there is a lot of space for scientific misdemeanor. Some journals recently started to require a full disclosure of all data and models on which they base their claims, which - surprisingly - isn't always the case.

As more data is gathered over time some models need to be adjusted. How much they need to be adjusted reflects quality of the model.

Re: What's Really Warming the World?

#145

Post by hackuser »

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…

I'm pretty sure your concerns have been addressed. Is it reasonable to 'lose confidence' because you haven't read the research?

Re: What's Really Warming the World?

#146

Post by dnautics »

hackuser wrote: post #145
dnautics wrote: post #132

Earlier quoted context omitted.

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…

I'm pretty sure your concerns have been addressed. Is it reasonable to 'lose confidence' because you haven't read the research?

pray tell, enumerate my concerns and show me how they've been addressed. Is it reasonable to assume they've been addressed just 'because scientists'?

Re: What's Really Warming the World?

#147

Post by 300bps »

jasonkester wrote: post #3

Cool visualization. It's worth keeping in mind that the modeled data lines up with reality because it's supposed to. That's how you calibrate your model, by making sure it fits reality. The real trick is to see how well your model extrapolates from the data you have out into the future. As in, if you feed it data up to, say, 1990, will it correctly spit out 2015 temperatures that fit the reality of 2015, or will it s…

Cool visualization.

I agree, but I have to say their imagination on what other things might be causing warming is not very robust. For just one example, there are at least two major effects of burning:

1. Release of chemicals into the atmosphere (ex: carbon dioxide)

2. Directly heating the atmosphere

There are literally billions of air conditioners, heaters, cars, factories, etc that all generate heat. The effect of these billions of heaters throughout the world definitely increases global temperatures. After all, this effect is a reason why cities are warmer than their surrounding rural areas (1). This is relevant because direct heating should be temporary while greenhouse gas increases are cumulative.

Honest question - has anyone calculated the effect of the direct heating on the atmosphere from the billions of heaters we use vs greenhouse gas increase?

----

(1) http://www.smithsonianmag.com/science-nature/city-hotter-cou...

Re: What's Really Warming the World?

#149

Post by pauleastlund »

mcv wrote: post #90
crimsonalucard wrote: post #79

Earlier quoted context omitted.

>Wasn't that Regret? I think the canon answer was 'belief', or more accurately, "Whatever you believe can change the nature of a man, can." Ravel actually accepted any answer.

Belief?! If that's true, the past 15 years of my life have been a lie! I honestly remembered regret as the correct answer.

Yeah, when I realized that Ravel accepted other answers it was like discovering Santa Clause wasn't real. "Regret" was the answer that made by far the most sense given TNO's narrative. Anyone who played and didn't choose "regret" was wrong.

Re: What's Really Warming the World?

#150

Post by saucetenuto »

mcv wrote: post #90
crimsonalucard wrote: post #79

Earlier quoted context omitted.

>Wasn't that Regret? I think the canon answer was 'belief', or more accurately, "Whatever you believe can change the nature of a man, can." Ravel actually accepted any answer.

Belief?! If that's true, the past 15 years of my life have been a lie! I honestly remembered regret as the correct answer.

Part of the point, I think, is that there isn't a single correct answer. The answer the Nameless One chooses is the answer which is capable of changing him.
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