I hope I’m not straying too close to any taboo subjects in this forum, but I have some questions about the exact capacity and capabilities of cloud seeding.
I have some minor background knowledge on this technology. For example, is uses compounds like silver iodine and dry ice to encourage already saturated clouds to rain earlier or with more rainfall. Studies put its water boost at about 5-15% more rain. Governments and militaries are not allowed to use the technology for their own purposes, so all cloud seeding is left to private companies.
However, I’ve seen a lot of people claim that cloud seeding is capable of much larger feats.
Online, a lot of people claim that “they” are causing large storms through cloud seeding, such as the large hail and snowing that occurred in Idaho earlier this Summer. Exactly why, I do not know, but usually people will say it’s something along the lines of trying to get people to seek to put data centers in Idaho or trying to cause some manner of crop failure. These theories are usually in tangent to theories of chem-trials and other aviation theories (which upsets me as a pilot because I’m sure I’ll eventually have at least someone ask me whether In dumping stuff or what not).
I don’t know much about how much energy it requires for weather to work (since the Sun is involved, I imagine a lot), or what laws of physics would prohibit the level of success that people claim cloud seeding can do, or even if it would be economically viable to do in the first place, which is what I was hoping one of you guys would know.
Cloud seeing is real but what you are talking about sounds like chemtrail conspiracy type thinking. Anyone can claim anything online. Ask for the evidence. If none is provided move on. I would move on without asking for evidence though.
Snow is unlikely in a lot of places in the summer but it’s not impossible or unheard of. Anyone who studies meteorology understands that climate is what you expect but weather is what you get. There are always going to be places experiencing rare storms or extreme weather. There are a lot of places and lots of chances (time) for odd weather to occur.
A average size thunderstorm releases about 1 Hiroshima-sized bomb worth. Just does it much slower, hours instead of milliseconds. And the sun is the ultimate source for this energy.
The potential energy in a storm is measured by CAPE, which limits the maximum size of a storm, but there is also the possibility of a cap which limits the amount of the CAPE that is available.
Fun fact, almost all rain starts as snow that melts on the way down.
That is something thus I’ve had to learn to do when it comes to “discussions” online. I suspected that there probably wasn’t much evidence to support it but was still curious because I knew that the technology was at least possible (but didn’t think to the extent they said).
I tell my students that and it blows their mind. Just a quick clarification. I’m guessing about 75%. In the mid latitudes your statement is true. The Bergeron process explains precipitation in cold clouds. But clouds remain entirely warm in tropical regions leading to rain via collision and coalescence that happens on cloud condensation nuclei.
Cloud seeding is not yet a technology that we can use in any meaningful way. The first problem is that there has to be clouds. The second problem is that every significant location (farms, fields) will need their own well-maintained cannons or have to be close to an airfield.
That was true for the 1940s. I don’t know how it is in 2026. A drone swarm can produce sky images at night.
Sounds like people just don’t want to believe that the more severe weather is the impact of global warming like we know it is.
It’s not “they” who are responsible, it’s “we,” and that’s harder to swallow, especially if you don’t feel there is anything in your personal control that you can do about it.
I suspect some of these people are just confusing hail and snow. As far as I know, it never snowed in places like Boise during the summer last year. The freak hailstorm just made it look like it did. There was some unusual late season snow in the mountains (high elevation) caused by unseasonably cold air. They just got hit with a major hail storm.
You are right in that many weather events will be
and are increasing in intensity but the opposite extreme of blaming the government for a summer hail storm in Idaho is blaming it on global warming. More likely the people are just experiencing an odd weather event that is statistically going to happen on occasion whether or not we are warming up the globe or evil mustache twirling government conspirators are seeding clouds for some nefarious purposes. We need nothing to explain this outside normal atmospheric variability. Maybe the storm had some extra moisture due to climate change. Entirely possible.
Greenhouse gas emissions drive climate change. Weather is influenced by many factors.
Currently China is the largest contributor to global climate change. The US is a distant second. So there isn’t much an individual US citizen can do about it.
Among them, the warming of the oceans and changing currents.
Come on guys, the fact that global warming is leading to a higher incidence of severe weather events is not disputed.
There was a tornado 2 miles from my house in Glen Elyn, and another one a mile from my work in Orland Park, and another one where I used to live in Homewood on Monday. Nearby suburbs had 3 inch hail, and 4 inches of rain in an hour. It was the third day this summer we were without power for a day because of 75-100 mph wind damage. We are definitely experiencing more freuqent and more severe weather events per summer than 20 years ago.
No. It’s a scientific fact that humans are driving global warming and it is directly related to higher incidence of severe weather events.
And individuals in the US can do lots of things. For one, they can elect representatives that take science and environmental regulation, preservation, and restoration seriously.
In Nebraska we’ve been getting a lot of hail and thunderstorms. However, from a few of my buddies, these storms just happen. I suppose that it is important that, although climate change is probably having some hand in a lot of weather phenomena, we shouldn’t attribute every single thing to it, lest we start to sound conflicting or overly pushing this concept (which is a victory that the conspiracy theorists cannot be allowed to have).
If I could build such a device as a sort of visible “parable’ (or perhaps, ‘analogy’ rather) to share with my students, I would; but meanwhile here a description of it will have to suffice.
Imagine a bucket of water sitting on a shaking surface that keeps sloshing the water around in the bucket. Occasionally, some of that water sloshes over the edge and out of the bucket. Think of that ‘sloshing over’ as the unusually hot weather, or even as a ‘flood’ or a ‘storm event’. The water in the bucket represents all the heat in the atmospheric/oceanic heat reservoir. Now imagine that the bucket has a hole in it by which water drains out of it (and always has at a steady rate) - that represents ongoing heat loss from this large reservoir (say sequestering of heat into stuff in the ground, or loss of heat radiated into space). Poised above this bucket is a hose that that runs fresh water into the bucket. This is the naturally occurring sunlight / geothermal sources or any other natural thing that adds heat into our earth system. By itself, this is a ‘stable’ system (no mention of humanity yet) - i.e. yes, there is equilibrium, but one that includes occasional storm events at some statistical and observable frequency over long stretches of time. Ask any insurance company about this if you doubt it. They build their livelihoods on it. Okay - now - and this is the important part of my whole story: Now picture one more smaller hose above the bucket (not nearly so big as the sunlight hose to be sure), but a hose that is adding a steady stream of additional water into the bucket on top of all the water already being added. That will be the additional heat that humanity is also putting into the environment (i.e. mainly the extracting and burning of fossil fuels, but would include agricultural practices or anything that produces extra CO2 & other greenhouse gases). So now our bucket is, on average, sloshing over noticeably more than it was before. One can wonder, was this or that particular ‘slosh-over’ specifically due to the drops of water that came from humanity’s addition? Well - that’s going to be impossible to distinguish now, isn’t it! Because ‘sloshing’ was and always happens naturally at some average frequency anyway, so one is prevented from firmly concluding that this or that particular hurricane or hot weather episode can be directly traced to only that specific heat added by humanity. But only a fool would deny that the extra ‘water’ we’re adding is contributing to more sloshing over than usual. Scientists have shown, beyond doubt, that we’re adding that heat (via greenhouse chemicals and burning of fossil fuels) to the bucket, and that yes - it is increasing all the ‘sloshing’ in a statistically measurable way, and changing it at an historically unprecedented rate. Even taking into account various longer-term changes in solar cycles or other episodic changes nature goes through (that they can see and account for). If you can understand this, then you’re closer to understanding the nature and manifestation of anthropocentric climate change.
Edited to add: The only thing I can think of that is obviously wrong with my analogy above is that in the bucket system, slosh-overs are actually removing water from the bucket; whereas in our real system, a hurricane or hot weather event doesn’t actually remove any heat, but just shifts it from one part of the environment into another. So to make this more true we would need to collect any the water sloshed out and put most of it back - as in, it really stayed in the bucket all along. So if anything, my analogy is not severe enough.
Weather phenomena are complex, with many factors involved. What seems to be a fact is that the climate is changing in the predicted direction and that change is associated with extreme weather events more often than in the past.
One detail that is currently a hot topic in Europe is the growing number and scale of forest fires in Europe, Canada and elsewhere. In France and Spain, forest fires are threatening large cities and have lead to evacuations of hundreds of thousands of people. A fundamental reason behind the severe forest fires is a series of hot weather periods. Such hot periods have not been experienced previously, at least not during May-July. When the forested areas get dry and temperatures stay at 40 degrees Celsius, the likelihood of wide forest fires increase much. With winds, the conditions have even lead to such a fire storm that has never before been observed in Western Europe.
In Europe, this is widely seen as a serious warning sign of the ongoing climate change.
Models predict that with climate change, weather conditions tend to stay the same for longer periods - hot or cold, such weather periods may last longer than previously. Some areas experience long droughts, some areas increased precipitation with floods, some areas both. When annual precipitation increases, most of the increased rainfall comes down during <10 days per year, leading to huge floods, with drought periods between the days with pouring rain.
Warming oceans feed more humidity and energy to the storms. The number of storms may stay almost the same but with more humidity and energy, the storms may cause more damage.
Although there are people who deny the contribution of humans in the climate change, there is no doubt that the climate is changing and extreme weather conditions are becoming more common. I guess that >>95% of experts agree that human activity is a major cause behind the climate change, through increasing the amount of greenhouse gases into the atmosphere.
Edit:
the wide-scale forest fires and other destruction of forested areas may affect the formation of clouds and rain. Organic volatile compounds released by forest trees act as droplet nuclei (seeds) in the condensation of water in the clouds. When we lose the forests, there will be less water drops and hence, less rain.
It depends what you are talking about. The number of hurricanes is not increasing (the number of slosh-overs), but the intensity of them is. The mean number of tornadoes in US also seems constant. That is one problem with your bucket analogy. I’d say it works in terms of droughts though. What I find interesting is that droughts don’t even have to be due primarily to a lack of precipitation. Warmer air simply being able to hold more water vapor is a problem:
Compared to the period 1948-1999, the average drought area increased 17% over the western United States from 2000-2022 due to an increase in evaporative demand.
The problem I see in this thread is all extreme events are being treated equally and anecdotally.
I didn’t dispute that. I disputed attributing a single hail storm to climate change. It’s misleading.
You know as well as I do that anecdotes are not data. And the link between tornadoes and climate change is a very muddy area which you can see even in the IPCC reports. Convective storms that produce tornadoes require CAPE (basically energy which warming certainly adds) but you also need wind shear for tornadoes which is expected to decrease as poles warm and the jet stream (fast current of high upper level wind) slows. In the case of tornadoes, you then have human warming fighting itself.
Can you cite data showing tornado occurrence is increasing dramatically and severe connective storms? This also needs to be tempered by us having far better data today (cameras everywhere, radar and satellite coverage, a strong ground network of spotters etc) compared to in the past. We still have incomplete coverage and different definition. IPCC section 11.3 discusses convective storms:
In summary, because the definition of severe convective storms varies depending on the literature and the region, it is not straightforward to make a synthesizing view of observed trends in severe convective storms in different regions. In particular, observational trends in tornadoes, hail, and lightning associated with severe convective storms are not robustly detected due to insufficient coverage of the long-term observations. There is medium confidence that the mean annual number of tornadoes in the USA has remained relatively constant, but their variability of occurrence has increased since the 1970s, particularly over the 2000s, with a decrease in the number of days per year, and an increase in the number of tornadoes on these days (high confidence ). Detected tornadoes have also increased in Europe, but the trend depends on the density of observations.
We always have to ask if there is anything here beyond normal atmospheric variability? Those of us with operational practice at predicting the weather and enough sense not to be caught up in weather anecdotes (when I was young it snowed a lot every year), know how dynamic the atmosphere is and how much variability can occur season to season, decade to decade for a variety of factors, some we can explain and some we may only guesstimate. Sometimes a weather pattern sets up and a region gets a lot of storms in a short period. Some years and decades are stormier than others.
There is a lot of natural variability in the atmosphere and long term shifts like the ENSO cycle that everyone has heard about. That’s just one. Few people have heard of the PDO and AMO. There are ocean current shifts (IOD) and so on and a lot chaos. Are there cycles and combinations we still haven’t worked out yet? Probably.
My point is one has to establish what natural variability looks like without human induced warming (which is really occurring) and then collect hard data (we got a lot of hail in Idaho today doesn’t qualify) showing we are exceeding that which cannot be also explained by the many cycles and changes that regularly happen on a dynamic planet.
I believe we have seen a statistical increase in severe weather on some fronts (droughts, hurricane intensity etc) . But every severe weather event is not created equally and immediately attributing them all to human induced warming is premature and misleading.
One can try to hide behind details like that. Sure - maybe this or that particular kind of storm in some particular regions of the world might be happening less. It’s not about “what all technically qualifies as a ‘slosh-over’ event” (my simple given examples notwithstanding.) It’s about the general fact (now undisputed fact among those informed by science) of greater heat energy being added into the whole system by humans. The fact that this generally causes climate change has now also reached proportions to where even deniers are obliged to be making excuses for it or inventing other conspiracy theories (anything … anything at all) in order to evade or deny what science has been telling us all along. And in fact, what we’re seeing is that if anything, the effects of climate change and the time-scale it’s happening in has been underestimated … probably by all of us trying to be optimistic and hoping on the most optimistic scientific spins we can find.
Despite these challenges, studies have found a few trends in the United States by using portions of the record that are more reliable, like data for very strong tornadoes. Although the number of days with tornadoes has fallen, other trends are increasing, including outbreaks with 30 or more tornados in one day, the density of tornado clusters (i.e., tornadoes are closer geographically), and the strength of tornadoes. The distribution of tornadoes has also shifted eastward. These trends have not been directly linked to climate change.
You are correct that tornadoes have not yet been linked directly to climate change like hurricanes and wild fires have. But I am going to mentally put that in the “not yet understood” category. There are factors that make it difficult to study longterm trends when it comes to tornadoes.
That was true for the 1940s. I don’t know how it is in 2026. A drone swarm can produce sky images at night.