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U.S. Droughts Predicted to Be the Worst in 1,000 Years

scientificamerican.com

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Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#91

Post by code_duck »

brianbarker wrote: post #84
code_duck wrote: post #51

Earlier quoted context omitted.

One area the U.S. could definitely focus on is reducing food waste. Restaurants throw away a lot of food that was perfectly good 4 days prior. The habits of people here regarding food waste is significant, too - I have a friend who will go to Taco John late at night, get six tacos, three potato things, 10 packets of sauce, eat two tacos and a potato thing and leave the rest to waste in his kitchen counter. He sees it…

Late night runs to a place called Taco John? Sounds like a post-alcohol food run. Maybe start there with the food waste issue :).

If it was me, I'd out the tacos in the fridge and eat them the next day. I think he believes next-day tacos are worthless due to flavor and texture changes, or some vague philosophy of only eating the freshest fast food.

My girlfriend's son operates similarly; he often makes a box of macaroni and cheese for dinner, and only eats half of it. He refuses to eat left over macaroni, so regularly at least half the box is wasted. My suggestion would be to splits box in half prior to preparation, but so far that has yet to be impmemented.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#92

Post by ScottBurson »

brianbarker wrote: post #83
Florin_Andrei wrote: post #81

Earlier quoted context omitted.

Actually, in terms of side-effects, I think this is preferable to most other solutions. You can turn this one on/off very quickly (or shoot it down for a more permanent off setting if the control mechanisms get stuck). That's not so easily doable with dumping iron into oceans, etc.

I was coming to add this exact thought! A solution like the umbrella could be activated and easily deactivated at will, since it's a physical object that could change positions. The other solutions, such as putting chemicals into the sky or sea, cannot be reversed. Better hope they work correctly the first time!

Actually, the half-life of sulfur aerosols in the stratosphere is on the order of a few months. We would have to badly overestimate the amount required in order to put so much up there that waiting for it to fall out would be painful. And the proposal is not to put it up there all at once, but to do so gradually.

Nature puts a whole bunch of sulfur up there every couple of hundred years or so, through large volcanic eruptions, so we have a pretty good idea what the effects are. Besides global cooling, which of course would be the point, the major side effect is more colorful sunsets.

The most telling objection I've heard to the use of sulfur aerosols is that they do nothing for ocean acidification.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#93

Post by riffraff »

Florin_Andrei wrote: post #81
johnloeber wrote: post #33

Earlier quoted context omitted.

The issue with large-effect, untested ideas like this one is that while it might seem like an appropriate solution for this specific problem, it might carry enormous side-effects that we aren't really aware of yet (and that may be difficult to reverse).

Actually, in terms of side-effects, I think this is preferable to most other solutions. You can turn this one on/off very quickly (or shoot it down for a more permanent off setting if the control mechanisms get stuck). That's not so easily doable with dumping iron into oceans, etc.

the problem is if by the time you turn i off you have somehow tilted a situation off equilibrium (i.e. some previously underrated insect species disappears and you only notice when plant X stops growing).

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#94

Post by SeanDav »

emergentcypher wrote: post #44
[deleted] wrote: post #36

[deleted]

> So, scientists can't yet get the weather forecast correct for even part of an afternoon, in a single city... but they've got the next 1,000 years figured out? Let me know how that works out. If I can't predict what side of the coin will be facing up on the tenth flip, how can I possibly expect to be able to predict the average of ten years of coin flipping?

The difference between your example and the Weather/Climate example is that coin tosses are based on a mathematically random premise, climate change assumptions are based on giant, complex models with a large number of subjective inputs, many of which can trigger significant or subtle changes in outputs.

A climate model is not proof and can not (yet?) be reasoned about mathematically.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#96

Post by kaybe »

ScottBurson wrote: post #92
brianbarker wrote: post #83

Earlier quoted context omitted.

I was coming to add this exact thought! A solution like the umbrella could be activated and easily deactivated at will, since it's a physical object that could change positions. The other solutions, such as putting chemicals into the sky or sea, cannot be reversed. Better hope they work correctly the first time!

Actually, the half-life of sulfur aerosols in the stratosphere is on the order of a few months. We would have to badly overestimate the amount required in order to put so much up there that waiting for it to fall out would be painful. And the proposal is not to put it up there all at once, but to do so gradually. Nature puts a whole bunch of sulfur up there every couple of hundred years or so, through large volcanic…

Sulfur aerosols attack the ozone layer (using anthropogenic chlorine) - yay. And if we're not careful with horizontal distribution, the cooling of the troposphere below and the warming of the stratosphere by the absorbtion will be different in different places, and there will be changes in pole-equator (or smaller) temperature gradients, and this in turn will change circulation patterns, and boom, some other kind of climate change! (This happens for volcanism for example, because most volcanoes are at the equator.) I somehow doubt we can really control the distribution well, and long-term it might distribute itself differently due to changed circulation. Hm, I haven't seen model runs for this kind of thing, might be interesting. (I have papers for the base facts somewhere though. Most knowledge is from the well-studied Pinatubo eruption.)

Plus, what happens if we stop, for any reason? This could only be a temporary solution.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#97

Post by marcosdumay »

cryptoz wrote: post #2

Optimizing crop outputs for higher-than-average temperatures and minimal rain is very important. Agricultural innovation over the next 10-20 years is going to be fast-paced; it'll have to be, to keep up with local climate changes. I work in weather prediction and hope to improve weather forecasts for agribusiness. But what if our forecast ends up just being "Hot; no rain.". What will happen, where will the water come…

> Will the US and everyone else stop pumping CO2 into the atmosphere?

Unfortunately, that one is easy.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#98

Post by tim333 »

vixen99 wrote: post #95

For an alternative view ('The paper has two strikes against it right from the get-go: paleoclimatological data and climate models') http://wattsupwiththat.com/2015/02/13/new-paper-unprecedente...

Glancing at the graphs

https://bobtisdale.files.wordpress.com/2015/02/figure-31.png

the correlation between the observational data and the computer models does not look that impressive so far. Maybe if the Southwest goes into an unprecedented drought shortly as the models predict then that would be some evidence that they have predictive power but so far it looks a bit iffy.

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#99

Post by fredup »

alexqgb wrote: post #70
nostromo wrote: post #47

Earlier quoted context omitted.

We could produce the same amount of food with a tenth the water we do currently. A simple system, like drip irrigation, could save 50%. An ebb and flow hydroponic system could save 95%. These technologies aren't new, they're just not cost effective until water becomes less cheap. I think in 20 or 50 years we'll look back at the current sprinklers that just spray water into the air as ridiculously wasteful.

The degree to which agribusiness in CA has been able to block any and all rational water regulation in the legislature is simultaneously awful and encouraging. Awful, because oh my god just look; the way they're handling this resource is demonstrably terrible. Encouraging because we are so amazingly far away from running an efficient enterprise. I suspect the Israelis could farm for a century using the same amount of…

It is certainly an exaggeration. A more accurate number could be 7-9 years.

Israel uses 1016 million m^3 of water [1] or about 800,000 acre feet on agriculture per year. While studies have shown that California as a whole could save 5.6-6.6 million acre feet per year while maintaining productivity and the same acreage farmed [2]. It is a bit more difficult to restrict the number to the central valley, but the central valley accounts for more than half of California's total agriculture [3], so we can just use the statewide number.

The entire state's annual agricultural water usage is less than 45 million acre feet [2]. Even if Israel had all of this water they would max out at under 60 years.

1. https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in... 2. http://www.nrdc.org/water/files/ca-water-supply-solutions-ag..., p.2 3. http://www.nass.usda.gov/Statistics_by_State/California/Publ... p.22-38

Re: U.S. Droughts Predicted to Be the Worst in 1,000 Years

#100

Post by bstpierre »

nothrabannosir wrote: post #77
rd108 wrote: post #75

Earlier quoted context omitted.

The best way to cheaply remove CO2 is to plant more trees. The simplest solution is still the best: it requires no new technology, can scale itself when the trees reproduce and is eminently accessible to all sorts of people, all around the globe. As an added benefit, some trees can even give fruit... which are delicious.

Don't forget: when a tree dies, the CO2 it absorbed is (indirectly) released back into the atmosphere. Unless you store the wood somewhere and keep it from being consumed by nature.

What about the half of the tree that's underground?
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