[KaiserJeep]

I think when you ignore the water vapor effects you cannot make a valid climate model. Which is pretty much why every single model that is based on carbon dioxide content alone is broken.

Do you really think that climate models are "based on carbon dioxide content alone" and "ignore water vapor"?

Nope, and I didn't say that. I am seeking to understand why no climate model yet invented has succeeded in modeling actual temperature changes.

What I mean by that is that you can take any model made, insert historical data, and then use it to forecast temperatures and temperature trends. But none of the models are accurate in predicting the same temperatures as were observed. In fact they frequently show an increase when actual temperatures decrease, or vice versa, meaning that both the direction and magnitude of the temperature are wrong.

My speculation was the models don't work because the models are focused on the wrong GHG. It would seem that you disagree.

I also speculated tha adding megatons of water vapor - known to be a much more potent GHG than carbon dioxide - via spray irrigation, might be affecting climate.

[dohboi]

"you show signs of understanding the various gas laws."
Everything I know, I learned from dis!

"no climate model yet invented has succeeded in modeling actual temperature changes"

But they have, broadly speaking. Do you expect them to accurately predict what the temperature is going to be at 2:35 pm this afternoon in Topeka, KA? If so, then, again, you are hopelessly lost. But they have successfully estimated the range of expected temperatures that we have seen. (I'll let others dig up the studies.)

"My speculation...I also speculated..." Speculate all you want, just please keep it to yourself next time.

Again (and again and again and again...), THIS IS NOT A THREAD FOR DISCUSSING THE PHYSICS OF CLIMATE CHANGE. (Sorry to shout, but really, will nothing get through to this guy?)
START YOUR OWN DAMN THREAD ON YOUR F'NG LITTLE PET THEORIES, IF YOU WANT, JUST GET THEM THE HELL OFF OF THIS ONE!!!!

[Newfie]

Or just ignore him. After all your own actions are all you really control.

[dissident]

I think when you ignore the water vapor effects you cannot make a valid climate model. Which is pretty much why every single model that is based on carbon dioxide content alone is broken.

Do you really think that climate models are "based on carbon dioxide content alone" and "ignore water vapor"?

He obviously has no clue what a GCM is. Having run several as part of my job I can tell that:

1) They have actual radiative transfer calculations based on the concentrations of H2O, CH4, CO2, N2O, O3, CFCs and other gases. These gases are proper advected tracers in GCMs and not prescribed climatologies.

2) GCMs actually do a very good job of simulating the temperature structure of the atmosphere. This includes the height and shape of the tropopause (it is much higher in the tropics than in the extratropics). So they actually solve properly the key processes of the atmosphere. A CO2 based model is some sort of irrelevant joke.

3) The distribution of H2O and other trace gases such as O3 and CH4 are captured within 10% of observed values.
(The simulations from many different models are routinely compared with observations and with each other, so climate scientists aren't just whistling in the dark).

Funny how people love to stroke their egos about the technological achievements of humanity. One such achievement is the capacity to simulate the ocean-atmosphere system in a physically realistic way based on first principles equations (Navier-Stokes for dynamics and the radiative transfer equations). Yet deniers would have everyone believe that climate science is no better than divination with bones. Clearly deniers have an agenda. There is nothing honest about their "skepticism".

[Lore]

I also speculated tha adding megatons of water vapor - known to be a much more potent GHG than carbon dioxide - via spray irrigation, might be affecting climate.

Where did you get this crazy idea? At best any increased evaporation from irrigation would be local. Water vapor does not mix well in the atmosphere like CO2. And if you stop to think a bit, irrigation would only add a fraction of a fraction in the amount of moisture to the atmosphere compared to the 70% of global surface area covered by water. Not to mention, you can only add just so much moisture to the atmosphere, dependent on temperature, before it would just condense and fall out as precipitation.

Oh, and thanks dissident for your usual thorough summation. I'm always impressed with your knowledge of the working science.

[dohboi]

Thanks to both dis and lore for their constant sanity and informed posts.

[dohboi]

http://www.motherjones.com/tom-philpott ... we-thought

40 Million People Depend on the Colorado River. Now It's Drying Up.

Science papers don't generate much in the way of headlines, so you'll be forgiven if you haven't heard of one called "Groundwater Depletion During Drought Threatens Future Water Security of the Colorado River Basin," recently published by University of California-Irvine and NASA researchers.

But the "water security of the Colorado River basin" is an important concept, if you are one of the 40 million people who rely on the Colorado River for drinking water, a group that includes residents of Las Vegas, Los Angeles, Phoenix, Tucson, and San Diego. Or if you enjoy eating vegetables like broccoli, cauliflower, and spinach during the winter. Through the many diversions, dams, canals, and reservoirs the river feeds as it snakes its way from the Rockies toward Mexico, the Colorado also provides the irrigation that makes the desert bloom in California's Imperial Valley and Arizona's Yuma County—source of more than two-thirds of US winter vegetable production.

We've known for a while that the river's ability to meet such demands has become increasingly strained. Climate change means less snowmelt in the Rockies, the river's source, and a 14-year drought in the Southwest has further impeded its flow, while adding to the demand on it. "The once broad and blue river has in many places dwindled to a murky brown trickle," the New York Times reported in January. "Reservoirs have shrunk to less than half their capacities, the canyon walls around them ringed with white mineral deposits where water once lapped."

[Keith_McClary]

Or if you enjoy eating vegetables like broccoli, cauliflower, and spinach during the winter.

Do we still get Cheetos and Twinkies?

[dohboi]

lol. Aren't those completely produced directly from fossil fuels, anyway??

Meanwhile:
http://www.climatecentral.org/news/clim ... pply-17891


What Climate Change in the Rockies Means for its Water

The Colorado River. The Arkansas River. The Rio Grande. The San Juan River. The Platte River — North and South. Altogether, they provide 19 states with drinking and irrigation water, including the cities of Los Angeles, Phoenix and Denver, among many others.

All of the water in those rivers comes from one source: the Rocky Mountains’ snowpack, which is expected to shrink as temperatures rise in a warming climate.

That’s why a new report by Colorado’s state water authorities showing how climate change will affect water supply there is so important. How much water is going to be coursing down these rivers in a warming world is highly uncertain, and that means the millions of people downstream of Colorado have a lot at stake.

“Already, snowmelt and runoff are shifting earlier, our soils are becoming drier, and the growing season has lengthened,” Jeff Lukas, lead author of the report released by the Colorado Water Conservation Board and the Western Water Assessment, said in a statement. “Wildfires and heat waves have become more common, too. Climate projections suggest those trends — all of which can affect water supply and demand — will continue.”

[dohboi]

If You Think the Water Crisis Can’t Get Worse, Wait Until the Aquifers Are Drained

We’re pumping irreplaceable groundwater to counter the drought. When it’s gone, the real crisis begins.

Aquifers provide us freshwater that makes up for surface water lost from drought-depleted lakes, rivers, and reservoirs. We are drawing down these hidden, mostly nonrenewable groundwater supplies at unsustainable rates in the western United States and in several dry regions globally, threatening our future.

http://news.nationalgeographic.com/news ... picks=true

[jedrider]

We should probably also note that the water vapor effect reduces our ability to adapt to the increasing temperatures as well. A little more humidity and the temperature becomes uncomfortable. You can be in a sweat AND cold at the same time with high humidity. You can overheat similarly with high humidity.

[dohboi]

Good points, jed.

Meanwhile:

Indonesia’s forests so damaged they burn whether or not there’s drought

The research, led by David Gaveau of the Center for International Forestry Research in Indonesia, assessed greenhouse gas emissions from fires that burned for a week in June 2013.

While the fires were short-lived and almost entirely (82 percent) concentrated on already deforested lands representing less than 2 percent of Indonesia’s land mass they released 172 million metric tons of carbon dioxide, or up to 10 percent of the country’s annual greenhouse gas emissions.

The reason for the large emissions was 84 percent of the burning occurred on peatlands, which store massive amounts of carbon in their soils.

Read more at http://news.mongabay.com/2014/0821-defo ... fQeEU9e.99

[Graeme]

The World's Deserts Are Greening from Carbon Dioxide Fertilization

hanks to increased levels of CO2 in the atmosphere, the world’s deserts are getting a little greener through a process called “CO2 fertilization.” Scientists from CSIRO have been taking satellite data of the globe’s arid regions for the past three decades, and they found that there has been an 11 percent increase in foliage from 1982 to 2010 across parts of Australia, North America, the Middle East and Africa.

inhabitat

[dohboi]

Thanks for that, G. There are indeed some places in (or next to) some parts of some deserts where things are looking a bit greener.

But the headline is doubly misleading since such greening is certainly not happening everywhere in all of the "World's Deserts" as the title implies--no where remotely close. Further, the patches where some greening is in fact happening are generally the result of a much more complex set of circumstances than just "CO2 Fertilization."

You might want to take a brief look at sources before posting too much from them. These guys are also excited about mining the moon for all of our needs for the next 10,000 years, and other such technofantasies.

At least toward the end they admit:

...there will be secondary effects that are likely to influence water availability, the carbon cycle, fire regimes and biodiversity...

...[other parts of the Earth] have shifted towards becoming dryer, leading to desertification.

So they should have ended their title with: "...Or NOT!"

(The last sentence of the article seems to be completely incoherent, another red flag.)

[Graeme]

I just wanted to introduce the concept of "CO2 fertilization" because it seems that at least some deserts are getting greener. It would be interesting to revisit this topic in say 10 years to see what has changed in the meantime. Are deserts becoming less green?

[dohboi]

Yes, many are. Many are spreading. Some once-non-deserts are becoming deserts...
(See the rest of this thread for some details!)

Surprise, surprise--the world is a complex place!

I think the most interesting place to watch for greening is the southern edge of the Sahara. Mostly because of shifts in annual rainfall (iirc), much of the Sahel is indeed greening and moving into what had been the Sahara. This is being assisted by intentional efforts to create a green zone by planting trees and bushes along this corridor to insure that the Sahara doesn't move south. So it will be difficult to parse out how much one or the other thing influenced this development.

But the Sahara is more likely to move (or rather is in the process of moving) north--into MENA and southern Europe, helping spawn Arab Spring in the former and the famous PIGS economic meltdown in the latter.

[Graeme]

Good point. Another climate parameter to track - the changing distribution of rainfall!

[dohboi]

http://www.climatecentral.org/news/clim ... west-17969

Climate Change Ups Odds of a Southwest Megadrought

If you think the drought in California is bad, you ain’t seen nothing yet. New research indicates that climate change is giving a boost to the odds of long-term drought across the Southwest.

The research, published Thursday in the Journal of Climate, puts the chances of a megadrought lasting 35 years or longer at up to 50 percent in the region. It would be a drought of epic proportions that would wreak havoc on the region’s already tenuous water supply for its growing population.

So a mega drought is now more likely to happen than not. The time frame based on the following quote seems to be "at some point in the next century"...it would be rather nice to have a slightly more narrow range for when these things are likely to start--are we likely seeing the beginning of a 10 - 40+ year drought/megadrought now?

And the odds of a decade-long drought – like the Dust Bowl of the 1930s or Southwest drought of the 1950s – are around 90 percent, meaning it’s near certain parts of the Southwest will deal with substantial drought impacts at some point in the next century due to climate change.

And then there's:

There’s also a 5-10 percent chance that parts of the region could see a state of “permanent” megadrought lasting 50 years or longer under the highest-warming scenario, a greenhouse gas emissions path we’re currently on.

So does the fact that we are on the highest level of GHG emissions (and that we show no very serious signs as a global industrial society of diverging from that path) mean that the chances of such a permanent megadrought more than 5 - 10%??

[Graeme]

International Global Precipitation Measurement Mission Data Goes Public

The most accurate and comprehensive collection of rain, snowfall and other types of precipitation data ever assembled now is available to the public. This new resource for climate studies, weather forecasting, and other applications is based on observations by the Global Precipitation Measurement (GPM) Core Observatory, a joint mission of NASA and the Japan Aerospace Exploration Agency (JAXA), with contributions from a constellation of international partner satellites.

The GPM Core Observatory, launched from Japan on Feb. 27, carries two advanced instruments to measure rainfall, snowfall, ice and other precipitation. The advanced and precise data from the GPM Core Observatory are used to unify and standardize precipitation observations from other constellation satellites to produce the GPM mission data. These data are freely available through NASA's Precipitation Processing System at Goddard Space Flight Center in Greenbelt, Maryland.

"We are very pleased to make all these data available to scientists and other users within six months of launch," said Ramesh Kakar, GPM program scientist in the Earth Science Division at NASA Headquarters, Washington.

nasa

[dohboi]

If people haven't yet, do check out the cool video at G's link above.