Does the strength of Earth's magnetic field influence its climate? The strength and orientation of Earth's magnetic field varies with time.

Does this variation of the magnetic field have any influence upon climate? For example, is there any correlation between ice ages and strengthening or weakening or orientation of the field?

There is no significant geomagnetic influence on the cycle of glacials and interglacials. I think the easiest way to determine this is to consider geomagnetic reversals. A reversal obviously involves the largest possible change in the direction of the magnetic field (a full 180°). It also involves some of the largest changes in field intensity, because during a reversal the field intensity drops to a small fraction of its usual value before regrowing to ‘normal’ levels (e.g. Raisbeck et al., 1985). So, if we're expecting geomagnetic field behaviour to have any influence on climate, we'd expect the most obvious effects to appear at reversals.

We can look for this effect by comparing a δ18O record (which gives a proxy for global temperature and ice volume) with a record of magnetic reversals. Here's a figure of the LR04 stack from Lisiecki & Raymo (2005), showing those two records for the past ~5 Myr:

As you can see, nothing spectacular or even noticeable happens at the reversals (the black/white boundaries along the bottom of the plot). They don't seem to correspond to any particular point in the glacial/interglacial cycle.

Of course, it's likely that geomagnetic field strength has some influence on climate, and that these effects are simply swamped by other influences on the spatial and temporal scales we're looking at here. The first possible effect that came to my mind was the geomagnetic field's influence on the amount of incoming cosmic rays, which in turn has an effect on cloud formation. And sure enough, it turns out that Vieira and da Silva (2006) have found such an effect. But I suspect that once you start looking at >10kyr timescales and global signals, such effects get averaged out.

Lisiecki, L. E., & Raymo, M. E. (2005). A Pliocene‐Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanography, 20(1).
Raisbeck, G. M., Yiou, F., Bourles, D., & Kent, D. V. (1985). Evidence for an increase in cosmogenic 10Be during a geomagnetic reversal. Nature, 315(6017), 315-317.
Vieira, L. E. A., & da Silva, L. A. (2006). Geomagnetic modulation of clouds effects in the Southern Hemisphere Magnetic Anomaly through lower atmosphere cosmic ray effects. Geophysical research letters, 33(14).

There is a definite link between a weakening geo magnetic field and the climate if the geo magnetic field is weakening in sync with a weakening solar magnetic field .

Why? Because a weakening geo magnetic will compound given solar effects. When the solar magnetic field weakens one effect is an increase in galactic cosmic rays entering our atmosphere and some reaching the surface of the earth. The weakening geo magnetic fieldd will compound this. This increase in galactic cosmic rays will result in an  increase in global cloud coverage and an increase in major explosive volcanic activity and geological activity in general which will result in a cooling climate.

Evidence of this is already taken place with earth quake activity on the rise and global temperatures trending lower post year 2016.


Carbon dioxide on Mars, Venus and Earth Earth's atmosphere is 0.038% carbon dioxide. Mars's atmosphere is 95.3% carbon dioxide. Venus's atmosphere is 96.5% carbon dioxide.

If Earth's climate is controlled by CO2, then why is Mars so cold in comparison to Venus? Mars is very cold (average about –60°C) and Venus is very hot (+460°C).

Firstly, Mars is farther away from the sun than Venus or Earth, so it gets less heat from the sun. Secondly, Venus & Earth are volcanically active, whereas Mars is volcanically inert. Thirdly, the atmosphere on Mars is much thinner than those on Venus and Earth.

The density of the atmosphere on Venus is approximately $65\ \mathrm{kg/m}^3$, whereas, the density of Earth's atmosphere is $1.217\ \mathrm{kg/m}^3$ and the density of Mars's atmosphere is $0.02\ \mathrm{kg/m}^3$. Earth's atmosphere is 60 times denser than that of Mars; Venus's atmosphere is over 3000 times denser.

With such a thin atmosphere on Mars, there is little atmospheric mass to retain heat, despite the atmosphere being composed of 95.3 percent carbon dioxide.

The important difference between Mars and Venus is obviously not CO2 or water, or distance from the Sun for that matter, but the atmospheric pressure.
You can easily determine the surface temperature if you know a few parameters like the molecular composition/weight and the pressure using the Boltzmann constant.
Surface temperature is on no planet determined by only greenhouse gasses.


Is climate change a vicious circle? My question refers to the current process of climate change. CO2 is rising, which leads to the greenhouse effect, which raises temperatures. This leads to more wildfires, which reduces number of trees, increasing CO2 and reducing CO2 capacity absorption. Ice caps start to melt, which reduces sunlight reflection (less snow), trapping more heat on atmosphere. Water rises, taking over land and trees, further enhancing the CO2 absorption capacity. Oceans acidify, lowering their CO2 absorption capacity too. Etc etc.

It seems the process of climate change is a "vicious circle", with a lot of feedback loops reinforcing the trends.

Is this the case? Are there counteracting forces that go against this circle?

Related questions which imo do not provide an answer to this one: here, here.

There are indeed a lot of positive feedback mechanisms, i.e. a warm climate leads to a warmer climate. From this Wikipedia article, they are:

Carbon cycle feedbacks
Cloud feedback
Gas release
Ice-albedo feedback
Water vapor feedback

However, there are also a few negative feedbacks (same source):

Blackbody radiation
Carbon cycle
Lapse rate
Impacts on humans

Now the question is: what is the net budget between positive and negative feedbacks? To assess this, climatologists use some metrics, the main ones being "transient climate response" (TCR) and "equilibrium climate sensitivity" (ECS). From Knutti et al. (2017):

TCR is defined as the global mean surface warming at the time of
doubling of CO$_2$ in an idealized 1% yr$^{−1}$ CO$_2$ increase
experiment, but is more generally quantifying warming in response to a
changing forcing prior to the deep ocean being in equilibrium with the
forcing. Based on state-of-the-art climate models, and instrumentally
recorded warming in response to CO$_2$ and other anthropogenic and
natural forcings, the Intergovernmental Panel on Climate Change's
Fifth Assessment Report (IPCC AR5) assessed that the transient climate
response is 'likely' (>66% probability) to be in the range of 1 °C to
2.5 °C.
By contrast, the equilibrium climate sensitivity (ECS) is defined as
the warming response to doubling CO$_2$ in the atmosphere relative to
pre-industrial climate, after the climate reached its new equilibrium,
taking into account changes in water vapour, lapse rate, clouds and
surface albedo. [...] The estimated range of ECS has not changed much
despite massive research efforts. The IPCC assessed that it is
'likely' to be in the range of 1.5 °C to 4.5 °C.

Which basically means that the climate will get warmer in the future, until it will eventually reach some kind of equilibrium.

It isn't Co2 (sorry I know that's likely unpopular for most to hear), it's (primarily) the sun.

Real quick, rising Co2 doesn't cause wildfires, trees love Co2, visit a greenhouse. Wildfires are a result of (bleep holes) running around lighting fires. Look it up, nearly 200 people arrested so far in Australia for arson.

Ocean rise prediction data (focused on Co2) fails to account for increased plant intake due to plant growth explosion. Similarly, population reduction doesn't account for the 12 gallons of water that makes up an average male. Reduce population by 1 million average men, increase water levels by approx 12 million gallons.

The ice was always supposed to melt, it's a byproduct of a catastrophe.

However, the long answer to your point is technically "classified" by the U.S. military and a secret. It was part of my training in the USAF, couldn't do my job unless they told me. What's classified is less the information but more our comprehension of it. Foreign nations know of it, they just don't have the big picture. Once you know, Climate Change is literally a hoax as it's currently being peddled.

This is one entity that monitors the real source of our "Climate Change" NOAA

This site also has some good info; Earth's Electromagnetic Field

My previous source was NORAD, I'm retired now, can't access it so, NOAA is the closest thing I've found publically available. We referred to it as "Geo-Planetary Index", it was/is monitored by the "minute" because it's that critical to success of the military's mission.

I don't know if politicians know the truth but some manufacturers clearly do. One example; ECC_memory

I'm not a fan of using Wiki however, the author of this excerpt from the above link knows what I know; "research has shown that the majority of one-off soft errors in DRAM chips occur as a result of background radiation, chiefly neutrons from cosmic ray secondaries, which may change the contents of one or more memory cells or interfere with the circuitry used to read or write to them.[3] Hence, the error rates increase rapidly with rising altitude; for example, compared to sea level, the rate of neutron flux is 3.5 times higher at 1.5 km and 300 times higher at 10–12 km (the cruising altitude of commercial airplanes).[4] As a result, systems operating at high altitudes require special provision for reliability."

If the public really wants to have an appreciable effect on the temperature, find a way to make the roadways, solar panels white/reflective. Plant more green things...

Edit/Update: Just keep this in mind, Co2 not being the cause isn't my "opinion". It doesn't matter if you have a PhD in "Climate Studies", it doesn't change reality.

More things to consider:

How many colliders are on the planet? (Hint: 40% are underground/classified i.e. don't exist, why?)
What alternative things are they used for beyond scientific study?
When do they fire them?
Where are they geo located, what's unique about their placement?
Why are they often fired simultaneously on opposite sides of the globe?
Who controls them?

Answers those questions, you'll realize "they" know it's not Co2, and you'll know it too.


How could humans alter storm intensity or direction other than cloud seeding? I am familiar with the concept of cloud seeding, where precipitation can be induced with aerosols, thereby altering storm intensity further downwind.  Are there methods that could be used to drastically alter storm wind intensity or storm direction?  What technology could theoretically be developed in the future that used satellites, ocean networks, balloons, or other devices to curb strong winds (e.g. tornadoes or hurricanes) so that populated areas could be protected.  Or is a strong storm simply too large scale of an event to be altered significantly by humans?

There are numerous ways. Arguably, some we are already doing, but are not intended (such as urbanization and the emission of different pollutants). But I'll suppose you are wondering about intentional modifications. Moreover, this is perhaps too general of a question, as there are a variety of different types of storms, of varying sizes. I'll tackle what I can, in a reasonable fashion. And for the sake of argument, I'll just ignore the downsides.

Let me repeat that, I will ignore the downsides. This may yield a comedic effect.

Extratropical cyclones.

Being that these take the energy from baroclinicity, a good way of disrupting the intensity of these storms is to warm the cold area and cool the warm area. You can do whatever you want to do to accomplish that, be it drop a couple megaton nuclear bombs in the cold region, etc.

Tornadoes

One thing you need to know about tornadoes is that the storms that generate these rely on stability/buoyancy and shear. Leveling everything should reduce the shear. Covering the surface with ice should also promote a more stable atmosphere.

Hurricanes

Hurricanes derive much of their energy from the temperature and entropy difference between the surface and the tropopause. Also, increasing the drag can reduce the wind speed. Different ways to do these can be found in NOAA.

Certainly these aren't all the ways that the weather can be modified. But these are just some. Of course, anything we do may backfire. Extratropical cyclones serve a purpose-transporting energy and momentum. Even hurricanes move water vapor towards the poles. And to that, I'll quote Jeff Goldblum:

  ...[Y]our scientists were so preoccupied with whether or not they could that they didn't stop to think if they should.

Clap your hands ... this is the human equivalent of a butterfly effect. Storm systems are chaotic, so tiny perturbations to the atmosphere grow rapidly and, eventually, alter the trajectory of future systems.

The drawback of this approach is that it is impossible to predict the magnitude or direction of the influence you have on any given system. Clapping your hands will not affect the path of an approaching storm, but, according to Lorenz's theory of chaos, it will eventually affect the path of storms -- perhaps a few months later. Alter storm intensity or direction in a controlled way is much harder.


Why are most effects of the predicted climate change negative? Most of the commonly mentioned effects of the ongoing and predicted climate change are negative: more extreme weather effects, more destructive weather, more diseases, rapid extinctions, etc.

Why is this so?

It is clear that any rapid change brings many negative effects. We humans, as well as the biosphere, are adapted to the current conditions. Any sudden deviation from these conditions will take painful re-adaptation.

But my impression is that several of the commonly mentioned negative effects go beyond than what can be explained by just change. Is this really so?  If yes, would a cooling climate (beyond restoring pre-industrial conditions) bring more positive effects?

I would say that the reason is because human civilisation, and particularly agricultural practices, evolved and are adapted to the pre-industrial climate.  This means that any substantial change in the climate will require changes in our civilisation and agriculture, which inevitably has a cost.  So the reason that most of the changes are negative is not to do with the science, but to do with us.

Much has been said about the negative effects, but there are positive effects as well. In UK thousands of old folk are speeded on their way to the promised land by hard winters, so milder winters will save thousands of lives. Excessively hot summers can also cost lives, but in UK those killed by cold weather greatly outnumber those killed by heat waves. Another beneficial effect is that the NW and NE Passages will be opened up to shipping, enabling ships to take short cuts to their destinations, use less fuel and thus cut CO2 emissions. Another benefit, provided the heating doesn't go too far, is that warm climates have greater biodiversity than cold climates. Of course, that means that cold-loving species like Gyrfalcons and Ptarmigan will be pushed further north or onto higher ground (Gyrs have never bred in Britain,Ptarmigan do,and Snowy Owls occasionally). A number of new species including Little Egrets and Cattle Egrets are already colonising the south of UK.

A cooler climate would also have both positive and negative effects, but we are not likely to get that for some considerable time.


How will climate change affect the extent of the Sahara Desert? Will it increase the size of it? (perhaps by increasing the extent of the Hadley Cells)?

Based on past  events supported by archeological finds  climate change will affect it.
Here is a short quote from an about.com referencing National Geographic

  "... recent excavations at the site of Gobero in Niger indicate.
  Gobero is a cemetery site, including at least 200 human burials
  located on top of a ridge or set of ridges, sand dunes with a hard
  calcrete-fringe. These burials occurred in two periods of settlement:
  7700-6200 BC (called Kiffian culture) and 5200-2500 BC (called
  Tenerean culture).

  There, explorations by a team led by National Geographic
  Explorer-in-Residence and University of Chicago paleontologist Paul C.
  Sereno, have illuminated some small part of the last 10,000 years of
  the Saharan ecosystem. "

Some references cited include

Sereno, Paul C., et al. 2008 Lakeside Cemeteries in the Sahara: 5000
Years of Holocene Population and Environmental Change. PLoS ONE
3(8):e2995. Free article download available

Green Sahara: National Geographic Magazine September 2008.

  People lived on the edge of the desert thousands of years ago since
  the last ice age. The Sahara was then a much wetter place than it is
  today. Over 30,000 petroglyphs of river animals such as crocodiles[8]
  survive, with half found in the Tassili n'Ajjer in southeast
  Algeria.... The modern Sahara, though, is not lush in vegetation,
  except in the Nile Valley, at a few oases, and in the northern
  highlands, where Mediterranean plants such as the olive tree are found
  to grow. The region has been this way since about 1600 BCE (aka as BC
  or  4600 years ago), after shifts in the Earth's axis increased
  temperatures and decreased precipitation.

Citation: American Geophysical Union. "Sahara's Abrupt
Desertification Started By Changes In Earth's Orbit, Accelerated By
Atmospheric And Vegetation Feedbacks." ScienceDaily. ScienceDaily, 12
July 1999. .

Within the Holocene era, roughly the last 11,000 years, meaning the time frame within which the Western Sahara was sufficiently habitable to support a cemetery,  we have experienced a  "little ice age". The Holocene is generally described as beginning at the end of the last glacial period.

There has been climate variation during the Holocene such that the Sahara could support human life. It is fair to extrapolate that any future climate change will also affect the Sahara.

If you look at a world map you will see that the great dry deserts pretty much center  around the 20 degree latitude. Proximity to a large body of water does not mean that the  landmass can support vegetation. The Namib desert is south Africa stretches to the Atlantic coast as  the Atacama in Chile   has a very long boundary  with the Pacific. (The Atacama is also the driest place on earth)

If there is going to be an affect on a desert from climate change , it is possible that the  desert could extend to a major coast line. It would be reasonable that the North African coast could undergo desertification. It  is already  coterminous with the east and west coastal borders of Africa. If it expands , it can go north  or south. It already approaches the Mediterranean coast

Presumably the Sahel could also become drier and there is some indication this has been happening. The Sahel is where we find the great savannahs. That  region is most at risk for increased temperature or aridity. Movement in eh other direction- milder temperatures and  more  rain would be beneficial  and supportive of  animals and human habitation.

The arid region and the mean temperatures in the western Sahara are sufficiently  large that it seems unlikely the Hadley cell formation would be affected, but I am not a meteorologist, so I defer to  them on that point.

Facts:
The strip along the equator receives more solar radiation and hence there is more moisture in the air. This reduces the difference between maximum and minimum temperatures. As there exist more clouds the maximum temperatures are not as high as in other temperate regions of the Earth.
An If:
If there is global warming then the equatorial region becomes larger and, in the extreme limit all the earth would have equatorial climate.
Then:
With global cooling the process would be the reverse:
The equatorial area reduces, the air is dryer, increase of the contrast between maximum and minimum temperatures (diurnal and annual), increase the erosion and greater intensity of local winds.
So, in this global cooling scenario deserts get bigger.
Because the maximum temperatures are increasing, most people and also many scientists, get the wrong impression that we are living in a global warming cycle.

About the Sahel:
Most of the hot deserts extend from latitude 15 to 35º degrees because they depend on the trade winds. As explained above the long term evolution of the equatorial zone should be shrinking from a global cooling viewpoint and then the desert land strips will approach the equator invading the Sahel and the south of Angola.

EDIT ADD:
after 4 downvotes without any explanation on physics I will copy/past from  ENCYCLOPEDIA of PALEOCLIMATOLOGY AND ANCIENT ENVIRONMENTS - ARID CLIMATES AND INDICATORS

where you can find what I said above:

  Pleistocene accentuation of aridity
  Although deserts may have existed before the Pleistocene, there is evidence that aridity was intensified
  in many regions in the late Pliocene and Pleistocene. It appears to
  have become a prominent feature of the Sahara in the late Cenozoic,
  partly because of the cooling of the oceans and partly because the
  buildup of ice caps created a steeper temperature gradient between the
  Equator and the Poles. This in turn led to an increase in trade-wind
  velocities and in their ability to mobilize dust and sand. DeMenocal
  (1995) recognized a great acceleration in dust loadings in ocean cores
  off the Sahara and Arabia after 2.8 Ma, and attributed these to a
  decrease in sea surface temperatures associated with the initia- tion
  of extensive Northern Hemisphere glaciation. Likewise, loess
  deposition became more intense in China after around
  2.5 Ma ago and eolian activity in the American High Plains dates back beyond 1.4 million y BP . The study of sediments from the central
  parts of the North Pacific suggest that eolian processes (dust
  deposition) became more important in the late Tertiary, accelerating
  greatly between 7 and 3 Ma (Leinen and Heath, 1981). It was around 2.5
  Ma ago that the most dramatic increase in eolian sedimentation
  occurred – an increase that accompanied the onset of Northern
  Hemisphere glaciation. In Arabia, humid conditions in the late
  Tertiary caused deep weathering and fluvial incision of lava flows
  dated to 3.5 Ma. Such signs are absent in early Pleistocene flows
  (Hötzl et al., 1978).
  Environmental fluctuations within the Pleistocene
  All deserts show the impact of Pleistocene climatic changes; no deserts were immune. On the one hand, the deserts expanded
  from time to time, covering areas that are now wooded and forested. As
  a consequence, stabilized sand seas occur in areas where rainfall
  levels are currently in excess of 800 mm. A large tract of dead ergs
  occurs on the south side of the Sahara from Senegal in the west to
  Sudan in the east, while in southern Africa the Mega-Kalahari extended
  into Angola, Zambia, Zimbabwe and the Congo Basin.

As seen, the Deserts are a very recent feature on Earth, which means that the temperature in the past was hotter (and less global winds).

I'm consistent with data in the above topic and in the new model here presented  (hoho it is vixra, do not read it, it is poison):

A Model of Past Earth’s Climate from Isotopic and Biologic Data and Its Relationship with Orbits’ Expansion

The first model of the past hot Earth’s climate consistently indicated by isotopic and biologic data is here established. This model, here named Evolving Climate Model (ECM), accurately matches a 3 Gy long compilation of isotope $^{18}O$ data. An important consequence of the model is the fast increase of oxygen atmospheric level between 2 and 1 Ga (Gy ago); this is a well-known but until now mysterious occurrence, the Great Oxygenation Event. A solution is presented for the two centuries old “dolomite problem” and new explanations arise for a number of long lasting problems, such as the origin of petroleum or of proto-continents. Differently from the usual climate scenarios, the ECM presents ideal conditions for the massive production of long organic molecules. Critical occurrences of life evolution, such as the Cambrian explosion, are explained and fitted by the ECM, exposing a previously unknown connection between the evolution of life and climate. The most likely cause for this hot past is the expansion of orbits; it is verified that this phenomenon can explain the ECM, the receding of the Moon and the water on early Mars for the same value of H0 = 48 km s-1 Mpc-1, which, if not a coincidence, is a non-negligible result.


Does snow melt on ice? I looked up nearly everywhere on the internet, but couldn't find any evidence that snow wouldn't melt because of ice. When I look it up, it instead tells me how salt can melt snow. I'm NOT looking up on salt!

This is the best weather-related StackExchange I could find, so I posted this question on this website. Also, I live in a hot desert climate, so it'd be hard to test it out in real life.

Yes, a layer of snow on top of ice can melt in some circumstances. For example, one active area of climate research involves analyzing the optical properties of sea ice as they relate to incoming solar radiation. In some studies (e.g., Ehn et al. 2004) this involves snow layered on top of ice, with the snow explicitly melting (and later refreezing) over the diurnal heating cycle in some cases.

As a more specific recent illustration, this phenomenon was also reported for the Canadian Lowell Glacier in July 2018 by NASA. Abnormally warm air temperatures (up to 29°C/84°F, according to nearby surface observations) over several days resulted in the melting of surface snow while the deeper ice below remained intact - a process referred to as ablation.

Yes.. If snow is lying on ice and is warmed by sunlight then it will melt.


If planting trees is ineffective to tackle climate change, why do people plant them? I've read answers that outline how if we afforested large (continental-scale) masses of land, it would do little in the way of tackling climate change. While it would sequester $\small\mathsf{CO_2}$ for about a century after it was planted (while growing) before reaching equilibrium, the planting of large quantities of trees would also sufficiently decrease the albedo of the land in which it was planted, that it would hold in a lot more heat than the land it replaced (likely desert or otherwise barren land). This means that, all things considered, it would make a negligible, if not negative impact, in tackling global warming.

If this is the case, why do we associate "planting trees" as a good thing, on the scale of individuals planting individual trees? Is it because generally, these trees improve ecosystem vitality/diversity, or for some similar reason unrelated to climate?

Planting trees has a short term benefit in carbon sequestration but will not offset the carbon from fossil fuel burning. However, in some places trees provide a benefit of increasing soil carbon which can have a longer lasting effect. Thus, one benefit is to increase the time needed to implement replacements to fossil fuels. Trees can increase cooling through greater evapotranspiration than grassland, in some climate zones. That, however, may have an impact on water resources. Wood and paper products that are not recycled remove carbon from the natural system, although the effect is small.

Burning wood instead of fossil fuels has a positive impact on the carbon budget where the carbon is recycled back into tree plantations.

Planting trees is a good thing provided it is done properly. In Britain we have some valuable habitats such as heathland, peatbog, and wetland where planting trees would do ecological damage. If for example you managed to put a small stand of trees in an area of wetland, that would encourage hawks and corvids to take up residence to the disadvantage of wetland wildlife, and it's the same with heathland and peatbog. I doubt if it is possible to plant enough trees to make a major impact on the CO2 problem, but they will make some difference if only a small one, and in the right place can be a wildlife asset as well.

It would be impossible to grow trees in most true deserts, but in the Namib and Atacama there are places where sea mists roll in from the sea and condense on any object which protrudes from the sand. Maybe it's possible there. The most promising place for tree planting is in restoring the S.American rainforest, where there could be a huge environmental benefit. It could be financed with foreign aid money which wold go direct to impoverished rural communities, thus killing several birds with one stone.

There is a scheme underway in Britain to encourage the spread of sea grass meadows, which are important to the marine environment and apparently are more efficient at sequestering carbon than most things you can grow on land. Again the contribution will be small, but better than nothing. Sea grass is a true grass, but somehow manages to grow completely submerged in shallow salt water. Few people are aware of its existence. Restoring mangroves, which are basically small trees able to grow in tropical estuarine waters, is another area of environmental improvement which would also assist in the battle against CO2.


Are hot springs in non-volcanic areas radioactive? Hot springs in non-volcanic areas are attributed to the interaction of water with hot rocks deep in the earth's crust:

  In non-volcanic areas, the temperature of rocks within the Earth also increases with depth—this temperature increase is known as the Geothermal Gradient. If water percolates deeply enough into the crust, it comes into contact with hot rocks and can circulate to the surface to form hot springs.
  Hot Springs/Geothermal Features, National Park Service

If I understand correctly, this heat comes from the decay of radioactive isotopes:

  ... the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle.
  Probing Question: What heats the earth's core?

Hence...

Question: Are hot springs in non-volcanic areas radioactive?

I'm guessing the answer is either "no" or "yes, but not very", because people swim in them.  But it seems like radioactive isotopes should be seeping into the water.

The answer is contained within your own question. Virtually everything is radioactive, including your own body, the air you breathe, and everything you eat. The radioactivity is usually beta radiation (emission of energetic electrons), which is the least harmful form of radioactivity.

Radon gas, which is emitted from granite rocks containing uranium, sometimes builds up to dangerous levels in our homes and is an alpha emitter. Alpha radiation is very ionising and dangerous, but needs to be ingested into the body to cause serious harm.

The answer to your question, therefore, is yes, hot springs are radioactive, but so are cold springs. As hot springs are more likely to have passed through granite rocks, they are probably on average more radioactive than cold springs, but neither are radioactive enough to cause concern.

The radioactivity which is dangerous enough to cause concern is radon gas, which varies from place to place according to the underlying rocks. Maps of radon hotspots can be obtained from the internet. If you happen to live in a hotspot, you need to keep your house well ventilated, otherwise the radon will build up to dangerous levels, sometimes levels which would not be tolerated in a nuclear power station or research establishment.


Where did the sand in the Sahara come from? If the Sahara used to be fertile and has since experienced minimal rainfall causing the current desert conditions, where did all the sand come from?
I assume the original dirt is still there, just underneath the sand.

The sand IS the original dirt, or at least what's left of it.
Sand is one of the major constituents of soil. Soils are roughly half minerals by volume and those minerals are silt, sand, and clay. In fact sand is often the largest single constituent of most common soils. Silt and clay are smaller and lighter, and can be moved by wind much easier when dry, this leads to the removal of everything but the heavier sand particles in very dry conditions.   What has happened is that without water and life to bind the material together, wind has removed all the lighter particles leaving nothing but sand and pebbles. Wind is good at sorting grains by size so each area tends to only have one grains size.
Where it came from originally
. Sand is just weathered rock, if you look at a map of the sahara there are quite a few scattered mountains and highlands in the desert. That is where the sand (and the original silt and clay) came from originally, weathering of rock, and the sahara is mostly exposed rock, with sand only making up a minority of its surface.
I suggest the wiki for getting started on soil science, if you are interested, https://en.wikipedia.org/wiki/Soil
More on what sand is, http://www.sandatlas.org/sand/
More on wind driven sorting, https://people.ucsc.edu/~jzachos/migrated/eart120/lectures_08/LECT7B.pdf

All of you dont account sand from the bottom of the Mediterranean... More recently than we'd like to admit, thousands of years ago, meteorites smashed into the Greece/Israeli regions flooding North Africa and sending Atlantis to its doom in Mauritania.
Proof to my claim is being unearthed above the Dead Sea where sulfer, among other things, from a meteorite exploding upon entering the atmosphere has been found. An explosion of 10 megatons vaporized the Dead Sea region leaving the aftermath as told in the bible.

What makes you think another meteorite couldn't have done this? Throw a rock in a shallow puddle and see what happens to the sand where and around you made the impact...


Why has the Earth's average sea level risen 'only' by nine inches after one degree C increase in temperature? I am only doing gross calculations here, but...
If the Earth has warmed by about one degree Celsius in the last century or so, and the thermal expansion coefficient of water is about .0002085, then the (admittedly salty) ocean should have expanded in volume by about .02%, or 1 part in 5000.  Right?
Well, the average depth of the ocean is about 10,000 feet, and if the water has (mostly) nowhere to go but up, shouldn't the seas have risen by about 2 feet, not .75 feet?
Ummm, I just thought of something...  Has the ocean not warmed as much as the atmosphere?

You should take into account isostasy. As there's more water in the oceans, the crust underneath bends under the weight, creating more room for it. At the same time, continental crust heaves above the oceanic, hence the small value.
A question here to be careful about is where the location of the measuring point, as it very well may not be stable.


Is 2015's record average temperature evidence that we are now experiencing runaway climate change? 2015 had the highest global temperatures on record, as discussed in this question, beating the last record ... in 2014.

Are we now in a runaway climate change regime, where zero further human impact on the environment will not prevent change to the equilibrium state of the Earth's atmosphere?

Runaway climate change is, given our current state of knowledge, only something that could be confirmed in historic context - in the rear-view mirror. Inconveniently, there's likely to be a much-diminished version of human civilisation around to observe it, if and when it does happen.

In other words, it's too early to tell if we've passed a catastrophic tipping point.

We don't know what the equilibrium state of the Earth's atmosphere is. It will take 30 years for our current stock of GHG emissions to fully show its effects: and we'll be continuing to release GHGs for a while, so the equilibrium will continue to change.

But it's worth bearing in mind what we can do, when we really have to; World War II saw massive realignments both in industrial production and in expectations within a very short space of time: after decades of delay, it now seems likely that decarbonisation will require at least a similarly fast and large industrial realignment; and it is possible.

According to satellite datasets (RSS), last year was not even close to being warmest ever. The warmest year still is 1998, and the second warmest is 2010.

It is beyond me why NOAA or NASA GISS (who use NOAA's data), ignore satellite measured temperatures, which give far more accurate and complete picture of the world's global temperature.

Below is a map of the coverage of the data NOAA and NASA GISS uses. I find it hard to believe they can tell us the global temperature in sufficent accuracy to claim whether some individual year was some hundredths of degrees warmer than some other.

There are almost no data on the oceans, Antarctis, Africa or the north pole. Just extrapolating the little data they have over thousands of kilometers just isn't going to produce accurate enough data to detect such a small changes.

This in mind, I'd rather turn to the satellites, which show nothing to be worried about.


How did plants adapt to $\small\sf{CO_2}$ levels past 400k years? Why won't they do it again? (Description from climate.nasa.gov: This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric $\small\sf{CO_2}$ has increased since the Industrial Revolution. (Credit: Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record.))
I'm not sure where and why has all $\small\sf{CO_2}$ gone every 100.000 years and out of where has $\small\sf{CO_2}$ come?
But if $\small\sf{CO_2}$ came from burning trees or volcanoes and disappeared because plants adapted then I have this question:
Plants somehow tolerated these 100.000 year $\small\sf{CO_2}$ changes over time which is very evolutionary small time. So perhaps adaptation was just about changing plants' composition percentages which is very flexible. When some rare $\small\sf{CO_2}$ eating trees came to be more frequent. But if that's true why can't plants change their composition again to adjust for human $\small\sf{CO_2}$-emissions pace?

I'm not sure where and why has all CO2 gone every 100.000 years and out of where has CO2 come?

The amount of CO2 in the atmosphere for the last 400000 years is very strongly correlated with temperature.

Temperature change (blue) and carbon dioxide change (red) observed in ice core records.
Image source: https://www.ncdc.noaa.gov/paleo/globalwarming/temperature-change.html.

Glaciations currently occur at roughly one hundred thousand year intervals, driven primarily by Milankovitch cycles. So what causes the strong correlation between temperature and carbon dioxide levels? The primary reason for this marked correlation is that carbon dioxide dissolves in cold water much more readily than it does in warm water.

As a glacial period starts, the oceans gradually get colder worldwide as ice gradually spreads over the Northern Hemisphere. This enables oceans to absorb carbon dioxide from the atmosphere. Atmospheric CO2 drop as a glaciation proceeds. The plot shows that both temperature and CO2 levels drop rather slowly over the course of a glaciation, and then both rise rather quickly as the glaciation ends.

One reason for this is atmospheric carbon dioxide levels. The Milankovitch cycles triggers the end of a glaciation. The warming oceans cannot hold as much carbon dioxide as they could during the depths of the glaciation and release carbon dioxide to the atmosphere. This exacerbates the warming, releasing even more carbon dioxide into the atmosphere. This makes the escape from a glaciation much steeper than the entry into one (Shakun 2012). A nice graph from the cited paper:

Upper plot: CO₂ concentration (yellow circles), global temperature (blue), and Antarctic temperature (red).
Lower plot: Simulation results that show that Southern Hemisphere temperatures tends to lead but global temperatures tend to lag CO₂ levels.
Image source: http://www.nature.com/nature/journal/v484/n7392/fig_tab/nature10915_F2.html.

  But if CO2 came from burning trees or volcanoes and disappeared because plants adapted then I have this question:

  Plants somehow tolerated these 100.000 year CO2 changes over time which is very evolutionary small time. So perhaps adaptation was just about changing plants' composition percentages which is very flexible. When some rare CO2 eating trees came to be more frequent. But if that's true why can't plants change their composition again to adjust for human CO2-emissions pace?

Your question is a bit moot since the increases in CO2 did not come from burning trees or volcanoes and did not disappear because plants adapted.

Jeremy Shakun, et al., "Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation," Nature 484.7392 (2012): 49-54.

Temperature and a alkaline soil with ph level over 7,Salinity and the suns radiation is a guarantee and the dew collected every morning is all most plant life needs to survive. Co2 is not even a factor. The Earth has lost all its Co2 plenty of times and the plants thrive along with the microbes to start life over.


Why is Egypt so dry? If you look at this wind map (for July, but following the link you can also view other months):

you will see that Egypt gets its air from the Mediterranean sea. During other months it could get less moist air, but still from the same direction.

If you look at the topography of Egypt:

(taken from Wikipedia), you will see that it doesn't have any mountain ranges that could intercept the precipitation. But it still receives very little rain.

I don't quite understand why. Is the Mediterranean air not moist enough?

If you take a look at the atmospheric circulation pattern, the Hadley Cells in particular, they tell the story. The northern edge of Africa is on the descending edge of a Hadley Cell, which means

  Having lost most of its water vapor to condensation and precipitation
  in the upward branch of the Hadley cell circulation, the descending
  air is dry. As the air descends, low relative humidities are produced
  as the air is warmed adiabatically by compression from the overlying
  air, producing a region of higher pressure.

The main air mass being dry already, and the High pressure system generated by the descending air mass along the 30 degree lines work to make the physics required for precipitation just not want to happen in these regions. You have to get a combination of enough humidity to reach saturation, and then cool the air to reach its dew point.  The desert region formed by the lack of atmospheric moisture(remember Hadley cell) can't add any humidity of its own through evaporation or transpiration, so the global patterns dominate, even being right on the oceans edge.

Note that Hadley cell edges at the 30 degree south also cut through the Namib,Kalahari, and in South America the Atacama deserts, with their own ocean exposure.

I suppose that the water gets lost to some underground aquifer. And then evaporates during the dry months.

http://www.mwri.gov.eg/PDF_files/Ground_Water.pdf

Otherwise it wouldn't be possible to explain why the water that rains down in the Qattara stripe doesn't evaporate straight away to cause rains further south, and so on all the way towards Sudan. It obviously can't drain towards the Nile, because the Nile basin in Egypt is very narrow.

(Combined graphics; basin outline: Nile Basin Initiative, precipitation map: Ministry of water resources and irrigation).


When is the next glaciation due? Let's say we invented a whizzy technology that took CO2 back to pre-industrial levels, say 280ppm, how long would it take for glaciation to resume ?

(I'm not angling for a denialist perspective here, I know warming is a problem)

This answer assumes 280 PPM CO2, at least until the ice age and oceans begin to draw CO2 from the atmosphere.

If we look at the Pleistocene and we measure how long glacial periods last and how long inter-glacial periods are, You could say, observing the Earth for the last 2.5 million years that being in an ice age is Earth's natural state, with only brief periods between ice ages.

Ice ages have also followed pretty regular patterns that makes them, in theory, somewhat predictable.   Ice ages mostly followed a 40,000 year cycle, between about 2.5 million years ago to about 1 million years ago, then switched to roughly a 100,000 year cycle over the last million years.

It's not precisely known why the cycle switched from 40,000 to 100,000 years.  That's known as the 100,000 year problem.  But if we use the current 100,000 year cycle as a ballpark measuring stick or if we measure the length of interglacial periods (which are generally pretty short, 10,000 - 30,000 years), then the next ice age can be estimated at not too far off.  Maybe 10,000 years.

But if we look closer at what actually triggers ice ages, which is (simplified version), colder summers in the Northern Hemisphere, driven by orbital variations.    We can get a better estimate when ice ages should come by looking for when the Northern Hemisphere summers will get colder.

Milankovich cycles don't always neatly line up and the right conditions for the next ice age, based on orbital changes is a bit unclear.  When the red line in this chart below is low ice ages are more likely to happen, and we're in a dip now, but coming out of a warmer summer period and relativly soon entering another one.   There's a slightly bigger dip that peaks in about 60,000 years from now, another one 100,000 years from now and a bigger one, about 130,000 years from now.

Using this chart as a guideline, the next glaciation is more tricky to predict.   Perhaps in 60,000 years.   These predictions are hard to make though because ice ages are self sustaining.

So, short answer, perhaps the best answer.   Nobody knows.   The Milankovich cycles aren't lining up in the right way to make this prediction easy.  We may be set for an unusually long inter-glacial period.

As for how catastrophic would it be.   Well, for one, we'd see it coming and stopping an ice age would probably be easier than stopping ice from melting.  Releasing CO2 and CH4 into the air for example.  For a longer answer, how catastrophic would it be is a world-building question.

There are two factors determining when the next glacial cycle.

The first concerns the natural cycle that has been at play since the beginning of our present day Ice Age (about 2.6 million years ago).  In this case the next glacial period ushers in as temperatures in the worlds oceans rise that in turn increases hurricane activity/force.  As hurricane activity eventually extends into winter months they bring blizzard conditions the likes of which are the building blocks of a glacial period. The increase in ocean temperatures is primarily the result of the North American and Eurasian tectonic plate adjusting from the previous glacial period, namely at the ice free peripheries that had bowled upward as a result of the massive glacial weight that covered continents.  These outer peripheries today lay mostly in the Oceans and so a resettling means “heat generated friction” as they grind along adjacent plates where the plate boundaries are convergent, and in the case where the boundaries are divergent, heat is generated as magma displaces into the ocean.

The second factor determining when the next glacial period is due, is as a result of man-made global warming.  This will certainly change the “natural” game plan.  In the past (without man-made global warming), interglacials lasted about 10,000–20,000 years, and so we can extrapolate from this that the next glacial period can begin any time in the near future and before 8,500 years.


Is a complete global flood physically possible on Earth? Genesis 7:11-20 presents an account of a precipitation event which, in 40 days, submerges the entire surface of the earth:

  [On] the seventeenth day of the second month — on that day
  all the springs of the great deep burst forth, and the
  floodgates of the heavens were opened…

  For forty days the flood kept coming on the earth… all the high
  mountains under the entire heavens were covered. The waters rose
  and covered the mountains to a depth of more than fifteen cubits
  [6.86 m].

Based on this account, my questions are:

Given the amount of water on Earth (including all the water as liquid, solid, and gas, in all possible places: the atmosphere, the surface, and underground), is there enough water to flood the whole earth until ‘all the high mountains… were covered’?
What is the estimated rainfall intensity based on this description, and how intense is it in comparison with today’s rainfall intensity in tropical areas?

Regardless of the veracity or otherwise of the account, this makes for an interesting thought experiment.

Just to add some further discussion to @Pont and @fre0n excellent answers.

The problem of the water needed to submerge the world during the Genesis flood have been discussed for centuries. The narrative could seem legit as  traces of marine condition can be seen even in high mountains. The Biblical flood was the most logic explanation for marine fossils and wave patterns far away from any coast. Moreover, at the time when the Bible was written in the Levant, there might still have been a collective memory of sudden sea level rise from the possible opening of Bosporus and flooding of the Black Sea. Other experiences, as tsunamis formed in the tectonic active Eastern Mediterranean would also add to the idea of flooding as a divine respond to human actions.

Early scientists that described and compared features in the nature, e.g. Ibn-Sinaa, could also see that some rocks was formed by water. They added the superposition principle, that younger rocks are situated above older rocks and that the processes that formed the rocks continues today and must have taken long time. What they could see, describe and test was a continuation of the earlier ideas of flooding, but they used reason instead of dogma. Modern disciplines of science, as radiometric dating and taxonomy, have further refined our understanding of time and the relation between water and dry ground, but we are still building on the traditions of earlier scholars as Ibn-Sinaa. Sometimes we prove them wrong, just like future scientists will (hopefully) prove us wrong, but the human wish to understand the nature around us can easily be traced back to Old Testament and before.

Sea levels are constantly changing during the history of Earth. There is a number of parameters that controls the global sea level, some are slow but have a large impact. E.g. during Ordovician, the sea level might have been 3-400m higher than today. Not enough to reach the foot of modern Mt Ararat, but the planet was certainly more blue when the first fishes appeared. Also during Cretaceous, the sea level was 2-300m higher than today and more recent, in early Holocene, the sea level was 120m lower than today. Our ancestors could walk (and maybe a short swim or paddle) from Asia to Alaska, from Java to Australia, and across the Black Sea.

So where did the water go? At colder conditions water can be be trapped in ice shields, glaciers. Antarctica and Greenland holds a rather large fraction of the global fresh water. But most water are in the oceans, and larger sea level changes must be caused by changes of the oceans.

The oceanic crust is, relatively to the continental crust, thin and soft, but get harder and chemically heavier with age. The oceanic crust press down the asthenosphere and this results in more space for water, and the sea level sinks (in relation to the geoid). Mid-ocean volcanism on the other hand lifts the seafloor and forces the sea level to rise. Temperature of water is also a factor to consider. Warm water is has less density and occupies larger volume.

The total change in sea level in the past 500 million years have been estimated to about 500m, this is impressive, but far more than the 3,896m of Mt Ararat, that was supposed to be covered in the Genesis flood narrative. As mentioned, there might be more water trapped in the mantle transition zone, but it's hard to see how it could have slipped out to form liquid water, and even more difficult, how it could get back to the mantle, against gravity, after the flood.

However, as a homage to the Biblical believes, there could be an interesting link between sea level changes and mass extinction. Changing sea levels, especially when it happens rapidly, results in new conditions that species might not have time to adapt to. The connection is discussed in this article by Hallam and Wignall, 1999 (Mass extinctions and sea-level changes). The article is also a good example of scientific methods and reason. The language in a scientific article might not be so colorful as in Genesis, but it can open a world far more complex and wonderful than any dogma.

Finally, a reading tip:
One solution is proposed in Umberto Eco's The Island of the Day Before, maybe the water was borrowed from another day, as the Earth contains two days, separated by the date line.

The primary source for the water that generated the flood was neither the upper mantle nor the atmosphere as rainfall, nor cometary bombardment or grazing, but earth's existing ocean water itself. Some water is liberated from the mantle in volcanoes and undersea vents, but these amounts are negligible except over very long periods of time.
Planet earth has a large amount of radioactive elements in its core and lower mantle. Radioactive element decay sequences, if they occur synchronized, could generate significant and rapid changes in the volume occupied by the elements, therefore, could rapidly change Earth's volume, same as a star can change volume in a collapse towards its core or in red giant phase but by a different process. If earth were to have shrunk, it would have displaced earths oceans to overwhelm the continents in wave after wave of tsunamis. If as the decay sequence continues, earths volume again increased, the water would have been displaced off the continents back into the ocean basins. No extra mystery water is needed to generate the flood, and no mystery as to where all the extra water went after the flood.
This radioactive decay would have generated massive heat, which would have shut off earth's protective electromagnetic field generating dynamo; however, an expanding earth would also create large rifts, and expose earth's mantle to the oceans, generating mass extinctions in the oceans, massive rainfall in equatorial regions, and massive blizzards at the poles; ergo, the ice ages; extreme cloud cover would have protected earth's life from cosmic rays till the dynamo turned back on; when the EMF turned back on centuries later, with rapid fluctuations, it seems to have generated a memory scrambling effect, recorded as The Tower of Babel event as the scrambling of languages.


Which part of solar radiation (VIS, NIR) keeps Earth warm? Which part of solar radiation (visible light vs. infrared radiation) plays main part in keeping Earth's surface warm?

Electromagnetic radiation converts based on frequency and exposure. Visible light and Infrared waves are the predominant energy sources that can penetrate the atmosphere. Higher energy wavelengths (UV and above) do interact but are often bounced by significant portions. Those radiations interact with atmospheric gases; emit infrared waves in the process.

Edit
I asked an AI your question, and got the following response.  I then analyzed / researched / verified it in the following sections.
Short answer - Infrared radiation is what heats the Earth the most, followed closely by visible light, though all frequencies do somewhat heat the earth.
AI generated answer to the question "Which part of solar radiation (visible light vs. infrared radiation) plays main part in keeping Earth's surface warm?":

The AI correctly responded with high confidence "Infrared Radiation".

My own human analysis of the AI's response:
This is produced by the Dragon AI in AI Dungeon, which is likely correct because infrared light has more of a heating effect than visible light.  This is correct per the data I researched below as well:
Researched answer: https://ag.tennessee.edu/solar/Pages/What%20Is%20Solar%20Energy/Sunlight.aspx

Much of the energy from the Sun arrives on Earth in the form of infrared radiation. Sunlight in space at the top of Earth's atmosphere at a power of 1366 watts/m2 is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light[1]. At ground level, this decreases to about 1120-1000 watts/m2, and consists of 44% visible light, 3% ultraviolet (with the Sun at the zenith (directly overhead), but less at other angles), and the remainder infrared. Thus, sunlight's composition at ground level, per square meter, with the sun at the zenith, is about 527 watts of infrared radiation, 445 watts of visible light, and 32 watts of ultraviolet radiation. The balance between absorbed and emitted infrared radiation has a critical effect on the Earth's climate.

If anyone can come up with another reference to strengthen this (or if anything contradicts this), please comment.  I was not able to find anything beyond this link online.


Can an earthquake occurring within two plates trigger another earthquake in a far away plate boundary? Can an earthquake occurring between two plates, like the Pacific Plate and North American Plate cause any effect which would trigger an earthquake in a far away place like the boundary between the Eurasian and Indian Plates, as we know it is a mosaic of plates?

I guess that it is possible.

As mentioned by others, on top of static stress triggering, which is the effect of an earthquake in its vicinity (typically up to 2-3 rupture lengths away), another way by which an earthquake can trigger others is by dynamic stress triggering, which may have effects farther away but are hard to identify and measure.

So far, the only earthquake that seems to have demonstrated how dynamic triggering over long distances can take place is the 2012 Indian Ocean earthquakes. This earthquake had an unusual combination of characteristics: it was a very large strike-slip earthquake, it took place in oceanic crust (which allows surface waves to travel longer) and had a very large concentrated burst of Mw 8.4 - 8.5 with large slip over limited distance (I do not post sources since there are at least 3 apparently good studies with very different results, for example one study says that slip exceeded 80m locally (!)). These characteristics suggest that this earthquake was very efficient at radiating energy through the crust rather than towards the interior or through very fragmented crust.

So, what this earthquake showed, is that it is possible to speed up significant earthquakes (earthquakes that were almost ready to happen, but they were sped up up to 90 days). Still, it is only one case, the mechanism is not well understood, we are not sure why this earthquake seemed to have caused this phenomenon while other earthquakes with higher magnitudes did not show the same effects.

Concluding, while static stress triggering has only a fairly local effect, dynamic stress triggering may have a wider effect but we only have detected one such case, which could very well have been a coincidence or due to an unusual mechanism. So the answer to your question seems to be yes, but with doubts and in any case for very special earthquakes.

I do not think that is possible. For one earthquake to trigger another earthquake at such large distances plates would need to be extremely rigid. Plates are far to ductile for stresses to be transported over such large distances.

In you specific example it seems even less likely. In your case stress would have to be transmitted over the entire pacific plate and then be transmitted over either the eurasian/pacific plate boundary or the indian/pacific plate boundary to be able to affect the indian/pacific plate boundary.


Need different temperature change data sets explained Nasa's temperature record is showing temperature increase. When I confronted a climate change skeptic with it, he replied that the data has been tempered with, and that there are different data sets which do not show temperature increase.

The exact reply was:

  According to RSS, UAH and radiosonde global temp anomaly datasets,
  there hasn't been a global warming trend in 20 years;

  http://www.woodfortrees.org/plot/rss/from:1996.6/to:2015.7/plot/rss/from:1996.6/to:2015.7/trend/plot/esrl-co2/from:1996.6/to:2015.7/normalise/trend/plot/esrl-co2/from:1996.6/to:2015.7/normalise

  GISS and HADCRUT4 datasets have added heat to raw temperature data to
  artificially keep the warming trend going as NOAA freely admits:

  https://www.ncdc.noaa.gov/img/climate/research/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif

This sounds reasonable to me.

Can anyone familiar with climate science explain why there are several data-sets, and why they are saying different things, and why NASA's set is the correct one?

There are several climate datasets around the world, two in America - NASA's GISTEMP, and NOAA's MLOST, and one in the UK - HadCRUT. These are the main datasets but there are others around the world, China, Japan etc.

The datasets differ slightly in the starting date, number of met stations included, degree of interpolation, and the way they get round the problem of lack of met stations in oceanic areas.

As to being 'tampered with', this is a subtle malicious implication that the data has been fudged. It is also an insult to the scientific integrity of the thousands of climate scientists involved, whose aim, as in all of science, is to get at the truth. Of course, the data have been 'processed'. This is an essential part of data quality control to interpolate missing data, and to ensure consistency of the data set. But no data has been 'tampered with' in the sense of trying to lead to false conclusions.
One of the striking features of all the global datasets is that, despite minor differences, they all show the same basic characteristics of an accelerating global temperature - the 'hockey stick graph'.

There is much dishonesty about, but not with the climate scientists. It is the climate skeptics who are being dishonest (not to mention scientifically incompetent).

Most estimates of global surface temperature "anomaly" come from NASA GISS network database http://data.giss.nasa.gov/gistemp/station_data/ .
There are some stations that show cooling trend over 100-year-long history of observations, as shown here:
https://stevemosher.wordpress.com/2010/09/29/needs-chec/
This is considered as a normal "bell-curve" distribution.

However, as it was noted in old discussions,  there are several examples where the OPPOSITE trend happens on ADJACENT stations that are only 50 km apart. This means that the spatial distribution of surface stations is insufficient to reconstruct characteristics of temperature field (averages, etc.), because the spatial sampling does not satisfy criteria for Nyquist-Shannon Sampling Theorem.

To get the sampling right, the station site locations must be at least half of 50km, or about 25 km apart around the globe. With Earth surface having 5×108 km2, the 25×25 km grid should have about 800,000 stations. Given 30% dry land, there should be about 240,000 surface stations to have any scientifically reasonable estimation of trends. This is the most conservative estimations for necessary amount of data to collect.The GISS network has less than 6,000 stations world-wide, which means that the data are undersampled by a factor of 40.

If one has a field so vastly undersampled, selective treatment of datasets could result in anything, which explains contradictions in various estimates.


What do continents "lay" on? It's a simple question.. What do continents "lay" on? Do they float on water? or are they huge bodies that "emerge" from the sea floor/bed? are they connected to the bottom of the oceans?  Hope the question is clear. Don't be afraid to be thorough and scientific in your answer, I'll appreciate it and do everything to understand it.

Matan, the continents where we all live "float" on the Earth's mantle. The continents are made out of relatively brittle rock called the "Crust" and the mantle is made out of much more ductile material. The mantle, however, is NOT liquid. It is just much more ductile than the crust so, in geologic time, it can flow (like silly putty). Also, the mantle is much more dense, so the crust doesn't sink into it by gravitational/bouyancy forces alone.

Think of it as a creme brulee. We live on the little hard crust on the top. And there just happens to be a little bit of water on that crust that covers the less-elevated parts.

Now, a little more technical, the crust that makes up the continents and the crust that is under the deep oceans are actually compositionally different. This is because the magma that solidifies to form each of these crusts travels, by partially melting its way up, through different materials and different thicknesses. The consequence of this is that the crust making up the continents is less dense than that making up the bottom of the oceans.

The image above shows the process by which we get new (left) oceanic crust, (right) continental crust, and (middle) a special type of crust like that in Hawaii. Note that when two tectonic plates collide, the more dense one will tend to subduct under the other.

[This answer has been highly critisized for using only the oversimplified descriptions used in school textbooks as an answer; the original answer is included only to make sense of the comments]

(I'm not a professional geologist; this is from my personal studies) Lava, essentially. The Earth is molten when you get farther down, and the surface of the planet is made up of large plates of stone, which very slowly get pushed around by huge swirls of lava beneath them.

Note that this is a very simplified explanation, but it seems to answer your question.


How can a storm drop 40 inches (1 metre) of rain? Hurricane Harvey dumped more that 20 inches (500 mm) of rain over a large region, with 40+ (>1000 mm) in some spots... and much more expected.

How is that possible?

Does the atmosphere really hold that much water?

Or is it getting repeatedly evaporated from the ocean and dropped onto the land by the circular winds, implying an enormous evaporation rate while over water?

You were right to question whether the atmosphere really held that much water.  It comes nowhere close!  We use precipitable water to track this, which is the measure of all moisture in the entire column of air in the troposphere.  We can get good widespread estimates from remote observations.  This animation shows current amounts of precipitable water levels across the US from satellite.  Here is a still from this afternoon (Sunday, August 27) during the Harvey event:

75 mm is less than 3 inches.

We also get in-situ exact measurements worldwide from twice daily radiosonde balloon launches.  Unfortunately none are located right near the locations receiving excess rainfall.  But you can check US sites of current precipitable water measurements any time by going to SPC's sounding page and looking for the PW value in the left side of the bottom table.  SPC also maintains a climatology page for precipitable water and other values.  You can see there that 3 inches (76 mm) of moisture in the sounding is extremely rare, and no US site has ever had 4 inches (102 mm) of precipitable water.

However, the answer is also not truly found in evaporation rates.  The conditions in strong hurricanes do greatly enhance evaporation rates due to the high wind speeds and warmer waters.  Measurements are actually a bit difficult to come by in such extreme conditions, with challenges in isolating evaporation effects from spray as well as in getting the instruments positioned into such environments (new field campaign: who wants to take the research ship out into the category 5 hurricane!?!).  As this 2007 study by Trenberth et al. noted:

  We are unaware of reliable estimates of evaporation in hurricanes, and published measurements do not exist in winds above about 20 m s−1 although some progress has been made in the Coupled Boundary Layer Air-Sea Transfer Experiment (CBLAST)

However, in that study model analyses suggested that evaporation rates in the core of hurricanes are likely no more than 1-2 inches (25–50 mm) per day.

How is that possible?

It's quite important to notice that heavy rainfall - well over 5 inches (125 mm) - can actually fall in as little as a couple hours almost anywhere, such as in this 2015 flood event in Nebraska.  How can that be?

The secret lies in the nature of even the weakest storm: even as a storm is just beginning to form, it begins to draw in air from surrounding areas.  This is NOAA's diagram of a typical developing thunderstorm cell:

You can see the curve at the arrows near the bottom, indicating inflow of surrounding air into the storm.  This inflow turns a thunderstorm into more of an engine, processing a continuing stream of incoming air, removing its moisture.  In a single cell thunderstorms in an environment without background winds, the "waste" air will eventually pile up and choke off the influx.  But even in such circumstances, a few inches of rain may fall.  That isn't by using up all of the moisture from the cloud's environment, but instead by using just a portion of the moisture from the reservoir in and around the cloud.

If some upper level winds exist to help exhaust the "spent" air, storm systems can persist for even longer periods of time.  For example, the Midwestern United States commonly sees long-duration late summer heavy rainfall initiated along stationary boundaries in which inflow lacks direct access to significant warm water bodies.

Larger systems that dump huge amount of precipitation over greater areas must pull in a more consistent, stronger inflow of warm, moist air from greater distance.  Examples of this happening include the Pineapple Express for rainfall in California/the southwest US, the low-level jet for spring and summer squall lines in the Plains, onshore winds during the Indian monsoon, and air from off the Gulf Stream in Nor'easters.

In all these regional large precipitation events moist air gathered from a great surface area flows into a smaller region.  As the air approaches, it is lifted by the low pressure and its associated features, condenses, and finally falls as rain (or snow).  This process is often termed "moisture convergence".  The Storm Prediction Center also offers plots of localized deep moisture convergence [choose a region, then look under the upper air menu].  The convergence contours, shown in red, really show the piling up of humidity that is causing the heavy rainfall in Harvey:

But perhaps to visualize the scale involved in creating a catastrophic largescale flood such as Harvey, this plot, created from a base image from pivotalweather.com, best shows the conditions around the storm (from the GFS model):

Basically the atmosphere of the entire Gulf (and beyond) is being pumped into the southeast Texas area.  So although the air can only hold a couple inches (some 50 mm) of water, and evaporation rates are typically only a fraction of an inch (several mm) per day... bringing that together from such a large source region, and focusing it down into one small area... can lead to these awful extreme deluges.

Addendum: It should also be highlighted that the NHC adds in their report on Harvey that rising motion was also enhanced by a front which had stalled in the area.  Air being advected in by Harvey's flow would naturally rise over that layer of cooler air when moving inland (a process called isentropic lift), which proves particularly efficient in condensing out the (abundant) moisture en masse into rainfall.  Most substantial regional floods require similar existence of a significant broad lifting mechanisms overlaid with such a relentless inflow of warm, moist air.

Harvey has been using a rainband to get water in from the Gulf of Mexico.

Think of the rainband as a pipe, it is piping water from the gulf to the core, and this pipe has a leaking problem, so the water gets dumped on Austin on it's path to the center.


Can the overuse of geothermal energy become an environmental concern? At what power output would we be using so much geothermal energy that we cool the core enough to endanger the Earth's magnetic field and have to stop using it? Is this a conceivable concern for a future energy crisis?

No, this seems highly unlikely.

According to online sources:

Average human power consumption in 2008 was estimated at 15 TW.

Total annual heat loss from the Earth due to the surface heat flux is estimated at 44.2 TW.

Estimates of the electricity generating potential of geothermal energy around the world are consistently less than 2 TW.

So although the average power consumption is a surprisingly large fraction of the total geothermal heat flux, the part that might possibly be extracted for power is quite small.

There are much more concerning environmental impacts to geothermal power development than freezing the core and destroying the Earth's Magnetic field. These include increased rates of release of carbon and sulfur into the atmosphere and land use issues.

The geothermal energy is produced in 3 main ways: When the Earth is formed eons ago, the kinetic energy of the mass that rammed into the surface of the earth turned into heat. Earth gravity force further compressed the materials that also generated some heat, element natural decay caused nuclear fission energy be produced.

Also, the Moon, the Sun’s gravity caused periodical (very slightly) distortions on Earth that also generate some heat though very little.

In these sources of heat: The Earth forming process stopped and the kinetic energy turned into heat no longer have supply. The gravity compress effect that generate heat no longer significant because matter already dense enough in Earth. Radioactive elements on Earth only can be consumed but no further supply from space; the heat they produced will be weaker and weaker when time elapse along. The tidal movement caused heat is too little on the Earth to compensate the loss of heat through natural dissipation.

The heat produced from the core (20×〖10〗^12W) cannot compensate the heat that being conducted to surface and dissipated out into space (44×〖10〗^12W).

So as an observed fact, the Earth’s total mass is cooling all the time. When there is no supply (or not enough supply) while there is a constant loss (natural energy dissipation) or accelerated loss (manmade energy dissipation by tapping into geothermal energy), it is a simple mathematical logic: the Earth’s geothermal energy is not sustainable --- don’t even mention renewable.

Someone argue: the Earth is so big and we are so small, we use a little bit of geothermal energy, it doesn’t matter. OK, if this proportional difference can allow human to use the geothermal energy long enough to the time the Sun’s life span is going to end and start to swell and scorch the Earth, then it makes sense. Otherwise it is non-sense.

Then how long it can last if we use geothermal energy?

Here is some rough calculation (because in this case we only need some qualitative analysis to decide sustainability issue on geothermal energy):

In 2006, human use 16 trillion w /s;
Earth total mass: 5.9763×〖10〗^24kg;
Mean density: 5517kg/M^3;
Estimated average heat capacity: 700 J/kg ℃;
Kilowatts/hour= 3.6×〖10〗^6Joule;
16 trillion w/s = 〖16×10〗^9kw×〖60〗^2s= 〖57.6×10〗^12kw/h;
1℃ down for Earth total mass:
5.9763×〖10〗^24kg×700 J/kg÷ (3.6 ×〖10〗^6Joule)
=1162×〖10〗^18kw/h;

How many years human use can cause 1℃ down for Earth total mass?

1162×〖10〗^18kw/h÷〖57.6×10〗^12kw/h×24h×7d×52w = 2309year

How many years human use can cause 200℃ down for Earth total mass?

2309year×200℃ = 461,800year

How many years we taking off our descendants by using geothermal energy for one year by this rate?

2 billion year/461,800year≈4331year

The heat inside the Earth is the living force that keeps the Earth alive --- the heat inside the Earth resist water be sipped into the Earth, keep the molten core flowing that maintain the magnetic fields of the Earth that protect all lives on it and that also protect the atmosphere not been blown away by solar wind, keep continental plates moving that make mountains which keep the Earth uneven to maintain weather and prevent all Earth surface be submerged into 50 meters of water…

Earth with weakened geothermal energy will become another Mars.


What determines the direction of wind What determines the direction that a wind blows?
I understand that the nature of my question is immensely broad but I see no other way to phrase the question.

The question surfaced in my mind when I was checking out the windmap for the South East Asian region as I was monitoring the haze conditions there.

snapshot 1602 GMT+8, 18 Sept 2019

moved my extra thoughts to comments so I don't bog down the actual description

Sunlight (heat), planetary rotation, and the shape of the land in passes over.

Prevailing wind is mostly caused by hadley cells, or the masses of air move due to the thermal difference between the pole and the equator as well as the surface of the earth and space. Thus it is the interaction of two different thermal convection cells. this moment twists into cells due the coriolis effect and the earths rotation.

Source

these cells can be somethat disrupted on the local level by things like mountains.

Most places have a prevailing wind, which is the main direction the wind comes from. In UK the prevailing wind is from the south west, which moving across the Gulf Stream gives us a mild, damp, marine climate.

Winds usually come in a rotating swirl which you can often see in satellite photos. It's a swirling air mass like a hurricane, but usually far less violent, and in a low pressure system north of the Equator the air moves counter-clockwise. Meteorologists call this a cyclone. If you can visualise one of these swirling air masses moving across UK or Malaysia, the leading edge of this rotating air mass might be blowing from south-east toward the north when it first touches land, but soon after, the trailing edge will pass over the same land, and then the wind will blow in the opposite direction. A high pressure system is called an anti-cyclone, and the wind from an anti-cyclone circulates clockwise in the northern hemisphere.

The speed with which it changes direction depends on several things, but mainly the size or diameter of the rotating air mass. There is this tendency for these rotating air masses to drift from  west to east. Winds are always strongest where there is low pressure and tend to be much calmer in high pressure.


Are there sufficient quantities of limestone to dump in the ocean to reverse acidification? This question asked: What is the evidence it is feasible to reverse ocean acidification by adding large quantities of a base (bicarb soda)?

The result was:

  Danny Harvey of the University of Toronto has already looked into this. His solution is to deposit 4 Gt/a of limestone into the oceans. To put this in perspective, global coal production in 2013 was nearly double this at 7.823 Gt and it is more than global iron ore production in 2014 of 3.22 Gt.

The respondent then posed the question: Are there sufficient quantities of easily obtainable limestone to do this?

My question is: Are there sufficient quantities of limestone to dump in the ocean to reverse acidification?

Getting figures on the amount of limestone available is difficult.

Apparently "limestone makes up at least 10% of the total volume of all sedimentary rocks".

One way to answer your question is by inference. Cement is manufactured from limestone. Current global production of cement is in excess of 3.27 Gt/a and by 2030 it is forecast to be approximately 4.83 Gt/a. Thus if all limestone currently earmarked for cement production were diverted to neutralizing the acidity of the world's oceans it could be done at short notice. How sustainable it would be over the 200 years required, is another matter. It also raises the question of what happens to all the industries and projects that current rely on a cheap and ready supply of cement?

With much tongue in cheek, the Florida peninsular in the US is predominantly limestone, likewise a significant portion of eastern England, with the "white cliffs of Dover, the karst regions of the eastern Adriatic, southern Europe, southern and eastern Asia and the Nullabor Plain in southern Australia. Would these countries be will to sacrifice their lands to neutralize acidity in the worlds oceans?

There doesn't seem much point in trying to 'de-acidify' something that is fact an alkali.

The pH of the sea has far more to do with its temperature then anything else, it's ability to hold $\ce{CO2}$ for example is dependent on this.

Acidification of the oceans is a myth, it is if anything, becoming less Alkali, closer to neutral pH.


IPCC digital references I'm tidying my citations for my thesis, and I'm facing the task of sorting out the references for the IPCC reports (all of which have very long lists of authors).
Does anybody know where there are any existing online .bib files or similar for these references? I'd really prefer to avoid adding them all manually if I can help it. For some reason the IPCC doesn't seem to do this as standard, which seems kind of odd.
Edit. OK I clearly didn't describe this very well. I'm after the references for chapters within the reports (as many as I can) not the references for information cited in the chapters. So AR5 WG1 CH1, Ch2 etc. etc.

Some of the IPCC AR5 reports were written in LaTeX, some in MS Word. You will not be able to get the .bib files for those reports written using MS Word because Word does not use BibTeX.
Working Group I did use LaTeX, and you can get the .bib files for their report, on a chapter by chapter basis, here.
Working Group II apparently used Word, but they have released a set of bibliographies in both .csv and .xml format. I used "apparently" because I am getting errors galore for any page under ipcc-wg2.org. Apparently IPCC Working Group II has not updated their subscription, and some expletive deleted online gambling company has bought rights to that domain.

You can copy-paste your reference from the instructions written on the frontpage of each report. For example, copy-pasted from the 2014 report:
Referencing this report IPCC,  2014:
Climate  Change  2014:  Synthesis  Report. Contribution  of  Working  Groups  I,  II  and  III  to  the  Fifth  Assessment  Report  of  the  Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.


Why do gold deposits form only in certain areas of the earth? In the map above you can find that most elements are spread evenly throughout Earth's crust and that they are available all around the Earth. However, gold can only be found in certain areas of the planet such as Australia and Canada. Is there a specific reason to why gold can only be mined at these locations or is it just a coincidence?

I'll take the form of the question given by another person here and attempt to provide a different answer.

So what you are asking is: "How did gold become so concentrated in certain parts of the world?"

So yes, gold is all around but the concentration is too low to make extraction of it worthwhile. You need some process to take small amounts of gold from a large volume and turn it into large amounts of gold in a small volume where it is convenient to build a mining facility and get it from the Earth.

One of the most common process to concentrate gold is through the action of hydrothermal fluids. This is basically heated water flowing through the Earth's crust. Heated water with certain properties such as acidity (pH) or dissolved anions (think chlorine-rich seawater is more corrosive than your tap water) can dissolve solid gold and put it into solution. Just like regular water can dissolve table-salt or sugar and put it into solution.

So you have this hydrothermal fluid flowing through huge masses of rock (mountain-like, but underground) for a very long time, and when it goes up to the surface, it is channelled into thin conduits of fluid flow. During their ascent the conditions change (be it temperature or pH, etc.) and the water are not capable of carrying gold with them anymore. This results in the deposition of gold in that specific region.

I made an example, that I hope will help you understand this in a clearer way:

So in here you have rain water, entering the Earth in a large area and getting hotter as they descend down. It becomes possible for them to dissolve the gold from the large volume of rock.  But also, because the water (now steam or a supercritical fluid) are hot they start to ascend upwards, usually through a narrow zone. When they cool down again, gold forms as a solid. For example, gold associated with quartz veins commonly forms through this process.

Now, what happens if these gold-bearing quartz veins are exposed on the surface? They may erode by rain and snow and get concentrated in river beds. So you can either mine the original quartz vein or the nearby river bed.

Gold is found all over the world. Where it happens to be most economic to mine depends on a range of random factors, including political factors.

One big factor in gold mining is the cost of labor. Places where labor rates are low are more likely to have people mining gold. There are places in Africa where people dig up gold with their bare hands.

There is probably plenty of gold left in California, but do you really want to restart hydraulic mining, washing entire mountains into mud to get that gold? Hydraulic mining was banned in California over a 100 years ago, but hey as long as you are willing to destroy every mountain in the Sacramento valley, we could start it up again and turn California into a gold mining district.

[Above] Hydraulic mining. We could make California a gold mining region again, but do we want to?


Precipitation and Elevation Does precipitation increase or decrease as elevation increases? Because I heard that in the mountains they get more precipitation due to the orographic effect and how the mountains drain the moisture from the clouds but in 8th grade my science teacher told me that precipitation actually decreases as elevation increases so I’m just confused?

What usually happens is that moisture laden air is blown toward mountains and forced to climb higher. As it rises, it tends to  become colder and less dense, so can hold less moisture. The surplus moisture is often precipitated in the hills or mountains, so when the air passes beyond the mountains there is much less rainfall. This is known as rain shadow. Here in Hereford UK we have plenty of rain, but not nearly as much as some places in the Welsh hills which lie 20 miles to the west of us, so I think we benefit a little from rain shadow. It was my experience in Borneo that there was more rain in the hills than at lower altitudes, but whether this holds true for the summit if Mount Kinabalu, which is over 12,000 feet high, I am not so sure. Probably not. More likely the rain is precipitated on the lower slopes.


Using Enhanced Rock Weathering in the Sahel Region of Africa A recent Guardian article "Spreading rock dust on fields could remove vast amounts of CO2 from air" has gotten some attention in the nongovernmental and UN organizations working in the Sahel who are desperate to combat the adverse effects of climate change in the region. This article is based on a Nature publication on enhanced rock weathering (ERW).
Let's pretend a large international organization has tasked a newly employed software developer to look into the feasibility of performing ERW in the Sahel. Now this let's say this software developer, who has no geological background whatsoever, is trying to figure out what it would take to run a ERW pilot in the Sahel and decided to investigate Bol, Chad to have a specific place to focus on.
Ideally, this pilot would seek to test two things (i) is ERW feasible to perform in the region of conflict, (ii) does the crushed basalt or silicate, which is added to the soil, increase crop yield?
In order to determine if this pilot is feasible to even consider I think the following should be investigated:

Current farming methods in the region
Feasibility of acquiring and transporting crushed basalt or silicate
Method for applying the basalt or silicate to the soil

What else should I look at?
If you were given this (completely hypothetical) task where would you start?
Is there any giant red flag I am missing which would be enough of a reason not to move forward with a pilot?

OK I did a paper on mitigating climate change by enhanced weathering of rock on agricultural land for my masters (2014) it's not brilliant, but it does include some useful references if you want to research this further.
I would imagine the main limiting factor in the Sahel region would be that the process needs to be wet. So you're possibly only talking about being able to add material to irrigated areas. There are also the limitations you've already discussed of getting the material on site. In terms of crop yield, I would suggest that it will only increase plant growth in areas which do not already have alkaline geology (and I have no idea what the geology looks like in the Sahel, I'm afraid) and adding too much to soils may well actually decrease site fertility without the addition of something else (manure is the traditional amendment)
As far as I'm aware, enhanced weathering is perfectly technologically feasible, but it does have a limited application - due to the sheer quantity of it we'd need.
Hope this helps.

More information on ERW here:
https://www.nature.com/articles/s41477-018-0108-y.epdf?author_access_token=w1xYBFb3g3BwKnjkBD1cJtRgN0jAjWel9jnR3ZoTv0NSaZpth7Zz94N6_lHXNgths4xErTsML30mZS8Ql0FCuzY9k6ePi5nMsoEvmCXoU5g65l-c0C09tp3iWQMGMdfvbuwlRhm5_snv9tqy8Kc6ig%3D%3D
Farming with crops and rocks to address global climate, food and soil security
Hot climates are good for ERW -- the kinetics of weathering are temperature dependent. But as noted above you need water too.


Why does haze and poor visibility present in stable air? Haze is not considered to be a cloud or mist, and it also is not fog.

What is the ultimate reason that haze and general poor visibility ranges prevail in stable atmospheric conditions?

Is the cause concentration of pollutants, some other effect caused by the presence of moisture/humidity, a combination of both, or something else completely?

Traditionally, haze has been regarded as,

  an atmospheric phenomenon in which dust, smoke, and other dry particulates obscure the clarity of the sky...

  Sources for haze particles include farming (ploughing in dry weather), traffic, industry, and wildfires...

  Whereas haze often is thought of as a phenomenon of dry air, mist formation is a phenomenon of humid air. However, haze particles may act as condensation nuclei for the subsequent formation of mist droplets; such forms of haze are known as "wet haze" ...

  In meteorological literature, the word haze is generally used to denote visibility-reducing aerosols of the wet type. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulfuric acid. The reactions are enhanced in the presence of sunlight, high relative humidity, and stagnant air flow. A small component of wet-haze aerosols appear to be derived from compounds released by trees, such as terpenes. For all these reasons, wet haze tends to be primarily a warm-season phenomenon.

A haze can also be considered an atmospheric colloid, where,

  one substance of microscopically dispersed insoluble or soluble particles is suspended throughout another substance.

Examples of atmospheric colloids include: fog, mist, clouds, condensation, smoke and atmospheric particulate matter.

The forces behind the suspension of haze particles includes: electrostatic interactions, Brownian motion, van der Waal forces, and entropic forces. The effect of these forces on the light (low mass) particles within a haze counter gravity to keep the particles suspended in air.

Haze can have a number of causes. Sometimes it is due to moisture in the atmosphere, but not sufficient to form clouds, and sometimes it is due to pollution. In Britain it can on rare occasions be caused by dust picked up from the Sahara desert and carried northwards. As you suggest, it can sometimes be due to a combination of causes. In heavily polluted London, many years ago, the lunchtime winter sun was so reddened with pollution haze that I was easily able to see sunspots with the naked eye. These were special circumstances, and I wouldn't advise anyone to try it nowadays.


Where can I find a list of active mining claims in my area (Northern Nevada)? I live in the Reno/Sparks area and have started rockhounding.  One aspect I am quickly realizing is that many sites are actively being mined.  In order to avoid running afoul of local laws, I would like to get a map of active mining claims and potentially a map of expired claims.  Expired claims would be helpful for finding interesting sites.

You may want to check this out ESRI open data http://opendata.arcgis.com/ if this is what you were looking for.

One another thing is that you might want to contact BLM's Nevada State Office.

http://www.blm.gov/nv/st/en/prog/minerals/mining.html

They may have the data if they are on the Public lands. I am not sure about the private lands for that.

An experienced rockhound would not be asking such a question, so my first points will be about safety. You definitely should not be in remote areas or around mines alone. You really need the buddy system when rock collecting. You also need proper safety gear. If you breaking rocks then full sleeves, long pants and safety glasses (or goggles) are needed. You need soft iron hammers, not a hard steel hammer like you would use for nails.

You should find a local rock and mineral club in your area. In that area such a group would organize field trips. Often clubs will allow members of other clubs join the trip. The clubs would know where to collect specimens and be able to show you such specimens which would show you what you are looking for. Such trips would be organized in such a way that you could find out what sort of equipment that you need.

Active mines will almost certainly turn you away. The mines that I've collected and that have had field trips do a massive clean up before having a public collecting day and only do so to try to create good will in the community. The insurance and liability problems are a nightmare for a mine.

The USGS has posted various lists of mines with GPS coordinates. You can also get mineralogy maps and topological maps from them.

Mine and Mineral Processing Plant Locations
USGS Mineral Resources On-line Spatial Data

Offroading has a webpage which has a spreadsheet with Nevada mine locations. (Click on title of article to download.)

Nevada Off Road ATV and SUV trail maps - Offroading Home
Overlays for Google earth. last two entries might be interesting.

USGS webpage with data for Nevada.

List of rock and mineral shows in nevada

The Reno Rock and Mineral Club is having its annual rock and mineral show this weekend. (May 7th and 8th,  2016.)

There are also books about rock collecting sites. For instance:

Rockhounding Nevada: A Guide to the State's Best Rockhounding Sites
By William A. Kappele @Amazon