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Messages - mitch

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Greenland and Arctic Circle / Re: What's new in Greenland?
« on: September 24, 2020, 09:37:34 PM »
The emergence of Indonesia for the draw down of atmospheric CO2 is an interesting hypothesis, but doesn't seem to match the paleo-CO2 records. I tried to get a copy of the paper but it is paywalled so wasn't really able to look at their arguments. Apparently a model shows that weathering there was sufficient to drive CO2 down enough to start Northern hemisphere glaciations.

Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: September 10, 2020, 11:16:16 PM »
Terrestrial storage of carbon does not depend so much on the forest trees but on forest soil--roughly 3 times as much carbon in the soil as in the biomass. Soil carbon is old, roughly 5000 years.  This is why oxidation of organic carbon in soils can be an issue in climate change.

Science / Re: Where are we now in CO2e , which pathway are we on?
« on: August 12, 2020, 09:39:45 PM »
The Guarino et al (2020) study that gave 2035 for BOE used CMIP6 models, which tend to have higher equilibrium climate sensitivity, and added the melt pond physics.  While it appears that 2035 is plausible, I will wait for more confirmation.  Or, we can all wait 15 years and see for ourselves. 

Consequences / Re: 2020 ENSO
« on: April 24, 2020, 10:05:40 PM »
The spring period is hard to predict through, and what we are seeing now is the upwelling part of the kelvin wave (the cool part) that has traveled from the western equatorial Pacific. The predictions don't call for a la nina, but a cooler than average neutral period.  Wait a few months and we will see.

Arctic sea ice / Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« on: April 18, 2020, 08:26:40 PM »
The big problem for a fleet of AUV's measuring ice thickness is the energy expended to ping on the subsurface of the ice.  This take significant energy, and batteries don't release energy well when they are cold. So, one has to work out how to recharge the AUV's.

The 2nd problem is tracking the AUV depth, since any depth error translates into an ice thickness issue.  It is possible to use pressure as a depth measure, but must correct for the salinity of the water, since adding salt to fresh water makes about a 3% difference going to ocean salinity. 

Policy and solutions / Re: Oil and Gas Issues
« on: April 15, 2020, 11:27:22 PM »
Given price of Canadian Tar Sands oil, maybe this means the end of the Keystone XL pipeline. One can only hope.

Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 13, 2020, 07:11:59 PM »
Removing the fresh water lens happens by mixing the deeper "warm" salty Atlantic waters upward into the fresher surface layer. This requires relatively large storms and no ice, since the density gradient is large.  Once the mixing is greater than the freshwater delivery, the surface warms up. 

Antarctica / Re: What's new in Antarctica ?
« on: March 13, 2020, 09:39:53 PM »
About the Antarctic core collection now at Oregon State University.  It was an archive facility at FSU. Most of the cores were collected off the USNS Eltanin, run by Lamont Doherty Earth Observatory of Columbia University and funded by the National Science Foundation's Office of Polar Programs.  The cores were taken by dropping weighted pipes into the bottom to collect layers of sediments. The ship also did large numbers of water sampling as well as mapping the ocean bottom by geophysical methods.

Science / Re: The Science of Aerosols
« on: February 12, 2020, 10:50:59 PM »
On the brighter side, some scientists have found that minor changes in altitude of jets would get rid of much of the warming contrail cover:


Science / Re: Where are we now in CO2e , which pathway are we on?
« on: February 03, 2020, 11:37:32 PM »
You don't actually get around the GWP20 vs GWP100 issue using Co2 equivalents.  Here is the NOAA website explaining how they calculate them:

The CO2e depends on a calculation of forcing. 

Science / Re: Carbon Cycle
« on: January 25, 2020, 10:30:45 PM »
During upwelling season along the west coast of the US, pCO2 in the water responds very strongly to the recycling of nutrients--particulate matter from the water moving offshore at the surface falls into the incoming water and degrades there.  This drives pCO2 to very high levels, sometimes > 1000 ppm

I guess we should encourage baby steps by BlackRock.  What about petroleum and natural gas? What about loans to FF companies?

The politics / Re: The Koch Watch Thread
« on: January 13, 2020, 09:08:39 PM »
At least Pompeo is out of the Kansas senate race. However, a lot of money are going to other GOP fringe candidates:

Antarctica / Re: Antarctic Icebergs
« on: January 05, 2020, 09:38:41 PM »
Westward drift? Antarctic Circumpolar Current flows west to east. 

If ferromanganese nodules are mined, it will be for the Co, Ni, Cu primarily, with a side of rare earth elements.  It will end up in a huge oversupply of Mn, which will have to be disposed of somehow. 

I doubt if the prices are such that a sustained mining operation could succeed. One mine of 2 million tons of nodules per year would produce roughly 2 times the current world supply of cobalt, assuming about 0.2% Co in a nodule. 

If there are a bunch of operations, there would likely be wild swings in prices. Furthermore the mining is essentially strip mining--the nodules took millions of years to grow. The sediment plume would be a major environmental problem of unknown consequences.

Science / Re: Carbon Cycle
« on: November 16, 2019, 05:12:35 PM »
I haven't read the Notz and Stroeve paper in detail, but they apparently relate sea ice area to cumulative CO2 emissions. I find that puzzling because the effects of current emissions are offset by a couple of decades. 

I think the paper is overly optimistic.  Incidentally, total CO2 emissions since 1750 is about 600 Gt C

Policy and solutions / Re: Oil and Gas Issues
« on: November 14, 2019, 09:17:39 PM »
The EIA being overly optimistic about fossil fuel production is not a new phenomenon, although Trump appointees may be pushing things further out to right field.  The other important point is that tight oil drillers are essentially mining their investors, not providing profits. There will be a tipping point, where many cannot raise  sufficient money to continue.  At that point there will be some major chaos in the oil patch. 

Antarctica / Re: Where is D-26 headed?
« on: October 20, 2019, 07:15:54 PM »
You are right, 300 m is a guess not a measurement. I was trying to find a temperature profile nearby, but was not able to in any reasonable time. You are right that bottom topography is also an issue with the bigger bergs. 

Antarctica / Re: Where is D-26 headed?
« on: October 17, 2019, 08:20:23 PM »
An iceberg as big as D-26 will stick down 300 m or more into the sea.  Currents at that depth are not necessarily going where the wind is blowing.  As for thinning, the temperature at 300 m is most likely warmer than the surface water, so most melting will occur from the bottom. However, being a tabular berg, it will just sink lower--the freeboard will remain about 10% of the total thickness.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 23, 2019, 07:24:23 PM »
No matter how good the processing power, the inherent instability in weather systems means that you are limited by how many observations you can make. If I remember correctly, even if you observe 99% of the surface today, by 10 days out you would only have reliable information about 50% of the surface.  You are trying to predict where the next bubble will form in a boiling pot of water a minute or so after the boiling started.  Here's a paper I located:

Consequences / Re: Hurricane Season 2019
« on: September 20, 2019, 08:19:46 PM »
The person is wrong about history. A hurricane hit San Diego in 1858:

Science / Re: Magnitude of future warming
« on: September 20, 2019, 08:15:45 PM »
There is an interesting paper in Science Advances:

That is able to use new models to model the Paleocene-Eocene thermal maximum.  They were able for the first time to get the response observed by paleoclimate data with the estimated atmospheric CO2 at the time. There is an increased equilibrium climate sensitivity with warming, caused by changes in cloud physics.

Unfortunately, if correct, it predicts an ECS of 4.2 deg C for a doubling from pre-industrial CO2. It doesn't seem to be paywalled.

China just announce that it would forgo the 10% purchase tax on Teslas:

They seem to want to encourage EV's, and perhaps because Tesla is building a Shanghai factory.

Science / Re: 2019 Mauna Loa CO2 levels
« on: August 24, 2019, 07:57:18 PM »
The change in annual atmospheric CO2 buildup depends strongly on the Amazon. If the Amazon is growing, CO2 is sucked into the forest but if it is not the terrestrial CO2 sequestration drops strongly. With a strong dry season and fires in the Amazon, as well as in the subarctic, we will probably see significant CO2 increases this fall.

Policy and solutions / Re: Renewable Energy
« on: August 21, 2019, 06:54:39 PM »
Yes, definitely a double standard.  At the same time the Trump administration is slow walking renewables, it is fast-tracking oil and gas permitting on public lands:

Policy and solutions / Re: Greta Thunberg's Atlantic crossing
« on: August 16, 2019, 08:25:37 PM »
Once Greta gets south of the Bay of Biscay, the seas don't look too bad. Here's a wave height forecast for the Atlantic:

Science / Re: Small changes can cause transition to a Pliocene climate
« on: August 04, 2019, 07:16:17 PM »
Going back to the Tierney paper--what they showed is that small changes in CO2 (280 to 400 ppmV) could make a model match the observations made by the paleoclimate community.  Despite what Tierney says, it does not say how easy it would be to convert from an interglacial to a warm climate. 

What impresses most paleoclimatologists is how long it takes before a change happens. Glacial-interglacial cycles happen because the world with northern hemisphere glaciations have two endpoints (cold and warm) that are hard to move past.  We are currently in a low albedo interglacial, so it is unclear how long and what CO2 will be needed to drive the world to the Pliocene state.

I just wanted to add a final point of information.  The PRISM (Pliocene Research, Interpretation and Synoptic Mapping) interval was chosen when the Central American Seaway was essentially closed and the Bering Strait was open, but before the initiation of Northern Hemisphere glaciation. Tectonic reconfigurations of ocean circulation are minimized.  Here's a recent report that will allow tracking back:

Science / Re: Small changes can cause transition to a Pliocene climate
« on: August 02, 2019, 06:02:54 PM »
The Tierney article said that the higher CO2 plus other feedbacks was sufficient to make a model look like the Pliocene, not that it would change the world into the Pliocene. You have to understand that the Pliocene deep ocean was about 2°C warmer than modern, a huge heat reservoir.  There will be several hundred years needed to warm the deep ocean by that extent.  If the ocean warms faster then the surface is kept more temperate.

There is inertia caused by the arrow of time--warm to cool is not the same is cool to warm.

Policy and solutions / Re: Why people don't listen to experts
« on: July 30, 2019, 06:04:50 PM »
We are in paranoid times when people think that experts are determined by "centralized power".  Instead, we find that groups pushing agendas tend to produce alt-experts that ignore facts.

Policy and solutions / Re: Renewable Energy
« on: July 29, 2019, 10:30:07 PM »
I just saw a release where University of Arizona scientists find a win-win for growing leaf vegetables under solar panels installed at 3-m minimum height. 3-m height is to allow tractors/farm equipment ability to access fields:

The crops also help to cool the solar panels, improving their efficiency. 

Arctic background / Re: Arctic Maps
« on: July 22, 2019, 08:37:03 PM »
When you refer to the "NOAA map" are you refering to the International Bathymetric Chart of the Arctic Ocean?:

The biggest problem in the Arctic is lack of data.  This is especially true on the shelf areas, because one needs to run a close grid of ship soundings to improve the map.  The version 3 of this map now has a 500 m pixel.

Glaciers / Re: Glaciers worldwide decline faster than ever
« on: June 09, 2019, 06:14:08 PM »
That most of the alpine glacier mass is in Alaska makes sense, since it sets next to a relatively warm water mass (the North Pacific), so has a major water source.  However, significant parts of the new deposition melt out every summer. Now that the temperatures have warmed, there is net loss along the glaciers.

Glaciers / Re: International project "Ice Memory"
« on: June 09, 2019, 06:09:12 PM »
ArcticMelt, you missed a digit on the Antarctic ice.  The ice age they report is 2.7 million years not 27 million years. Still an important achievement in terms of getting Pliocene CO2 data.

The rest / Re: SpaceX
« on: June 04, 2019, 05:26:26 PM »
It would be vastly cheaper to "terraform" earth, i.e. fix the climate problem here than to try to make Mars habitable.  Transport costs to Mars for sufficient numbers of humans and equipment needed are probably equivalent to the entire global GDP. 

Science / Re: Projecting to 2150
« on: June 03, 2019, 05:07:23 PM »
The main uncertainty with the projections is the human response--how much fossil fuel will be burnt before we stop.

It is important to go out to 2150 to show that the warming will not stop. It is also important to do a 2050 snapshot since most of the warming has already been baked in.  No matter what the scenario, the change in temperature/climate will be about the same. 

The rest / Re: Archaeology/Paleontology news
« on: May 28, 2019, 07:51:13 PM »
I tried to check out the paper, and found that all the data was in another that I couldn't access.  There is a problem when astrophysicists try to do geology--they don't seem to understand that the recording system is imperfect.  So the speculation without a tie to the actual sediment cores that they worked on is very untrustworthy.  Furthermore, they string together Fe-60 data from unknown sources to a dubious calculation of change in lightning frequency to disappearance of forests in Africa via lightning-caused fire. 

The likelihood that they are right is probably less than 10%.

According to the Wikipedia infobox, CO2 in the Paleogene period was 500 ppm...which we are now reaching the equivalent of, according to the above.
In the Paleogene, the poles were almost ice free, IIRC.

The Paleogene is the first part of the Cenozoic, so extends from 65-23 million years ago, so is 42 million years long.  The average CO2 was >1000 ppm until around 34 million years ago (Eocene-Oligocene transition, also known as the Greenhouse-Icehouse transition) and probably dropped below 750 ppmV at that time.  The drop apparently caused the formation of the East Antarctic Ice Sheet.  So, a 500 ppmV average for the Paleogene is probably low.

The rest / Re: SpaceX
« on: May 27, 2019, 06:39:29 PM »
I am always frustrated by people that say that space exploration is a solution to earth's climate change.  It is not, and means only that a few hundred people at a cost of 10^9 dollars per person will be delivered into an environment that is much worse than the worst environments on earth. 

Spend a few trillion and we can fix earth. 

Consequences / Re: Sea Level Rise and Social Cost of Carbon
« on: May 21, 2019, 05:57:27 PM »
Bamber et al (2019) are estimating Ice Sheet contributions to future sea level rise, not total sea level rise, including the thermal expansion term.  Add on another 15-30 cm for the thermal expansion.

Consequences / Re: Places becoming less livable
« on: May 16, 2019, 05:15:32 PM »
It is unlikely that it is pollution from resorts since the Yucatan Current runs along that coast at a 5 knot clip, moving North.  Playa de Carmen is not in that flow line. 

Perdue defending glyphosphates is a reflex action, not with any data to back it up.  It would be great if we could get some experts to explore the issue, like National Academy of Science. It won't happen with this administration because they want to control the narrative.

Policy and solutions / Re: Direct Air Capture (of Carbon Dioxide)
« on: May 01, 2019, 04:50:03 PM »
The problem with direct air capture of CO2 is what to do with it afterwards.  CO2 has roughly 2.7 times the mass of the original hydrocarbons, so need places with lots of room or where it can be reacted with basalt to fix it as CaCO3.  You could pump it into the ocean where there is plenty of buffer capacity, but that isn't good for the ocean biosphere. 

Policy and solutions / Re: Oil and Gas Issues
« on: April 27, 2019, 06:39:59 PM »
Interesting that the Saudis are admitting that their main oil field (Ghawar) is beyond peak oil and production there is declining. I think the Saudis are trying to get out of oil and into other industries. 

Driving up the price now would allow them to get maximum price for their remaining reserves.  The good news is that EV's are becoming a mature form of transportation.

I once saw a seminar by Courtillot where he attempted to construct a global temperature time series using 5 temperature records from Oregon.  Unfortunately he has started from the conclusion--no global warming--and then searches for evidence that fits that conclusion.

His biases are too strong for him to be a trustworthy source on climate change.

Consequences / Re: Widespread Ocean Anoxia to be Noticeable by 2030
« on: April 14, 2019, 06:05:02 PM »
Thanks for the second paper as well. I need to look into the systematics of U-isotopes, but would expect that the isotope anomaly would also match a low in U/Ca.  The main problem with the Paleozoic studies is that essentially all the preserved material is from shallow water--plate tectonics has wiped out Ordivician age sea floor.  So, significant confirming evidence is needed before the hypothesis is accepted. 

It is very hard to make the whole ocean anoxic, since cutting off oxygen to the deep prevents recycling of nutrients to the surface. Shelf areas are most susceptible, like the anoxia that now appears off Oregon, e.g.:

Consequences / Re: Widespread Ocean Anoxia to be Noticeable by 2030
« on: April 13, 2019, 06:31:58 PM »
Thanks for link to oxygen paper. If you glance through the paper, 15% of the oxygen change is because of changes in O2 solubility and higher kinetics of organic matter degradation in warmer water. The other 85% is caused by less exchange with the surface, because the ocean is heated from above. The warmer surface waters have a higher density gradient with those below. These gradients will get weaker in a few centuries because the subpolar regions are warming as well and they provide the waters underneath the mixing zone. The likelihood that we will drive the whole oceans anoxic is very small. 

Science / Re: Modelling the Anthropocene
« on: April 10, 2019, 06:46:54 PM »
Paleoclimatologists/Paleoceanographers don't use the Pliocene as an  analog but as a means to study the dynamics on a warm earth. They can infer if models contain all the processes that maintained global warmth.

Contrary to what a few people have posted, the Isthmus was almost emergent, with only a few passages around 50-100 m at the beginning of the Pliocene (5.3 million years ago [Ma]). Mammals started crossing between North and South America at around 3 Ma, which dates essential closure.

The Gulf Stream existed at that time, and so did the Pacific trade winds driving the South equatorial current.  The eastern Pacific was warmer, but that is due to warmer subarctic conditions.  If you want to get an idea what is being done, here is a site to look at:

Science / Re: 2019 Mauna Loa CO2 levels
« on: March 18, 2019, 11:57:56 PM »
pre-industrial CH4 was about 700 ppb vs about 1800 ppb today:

One should be able to make a pre-industrial CO2e.

I worry more about nonlinear effects--warming of ice sheets and decrease of viscosity. There is roughly an order of magnitude decrease as an ice sheet warms from -10C to near freezing:

The paper is open source.  Colgan et al were arguing for a potential for ice sheet collapse via meltwater transfer of heat to the base of Greenland glaciers. The 'good' news is that it may take 4 centuries. 

Consequences / Re: Floods
« on: February 19, 2019, 05:01:21 PM »
Look on the bright side--storing excess water on land leads to a temporary sea level fall.

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