Several hundred years in the future, technology has significantly advanced to the point where we can far more efficiently extract energy out of the natural world we live in. As a result, energy has become far cheaper, and completely renewable, significantly boosting the economy and sparking innovation. Quality of life jumps up, and with our new money, we move a lot of our focus on climate to focus on philanthropy. Using our new energy, we have drastically improved most third-world countries, westernizing them and almost entirely eradicating poverty.

Another side-effect of this new energy is that climate change has become a thing of the past. It has been replaced by climate-control. We can't change the world temperature overnight, but we can safely and accurately change the temperature by a couple of degrees Celsius per year, with practically no limit on how much we change it (other than, of course, humans have to survive to continue to change it). In comparison, we have very little control over the weather, but we do have some.

Everything in the world is better. There is only one downside. Overpopulation. The economy is great, standard of living is great, no energy crisis, but we are running out of land for the people to live in. We also need more room for agriculture. Space colonization is out the window, as our space travelling abilities have not progressed very much since modern day. However, we have another weapon: Terra-forming the earth. 70% of the surface of the earth is water. If we can bring that number down, we will have more room. How do we go about this?

When the idea first came to me, I thought "Bring the temperature up! That way, more water will evaporate, the ocean levels will fall, and previously underwater land will become beach, previously beach will become habitable land!" I immediately realized that this is a terrible idea. This would

  • Melt the poles and bring the water level up,

  • Destroy a lot of agriculture,

  • Make a lot of desert areas uninhabitable,

  • Make humans pretty grumpy

and probably a million other things that I can't think of at the moment.

Then I thought "Let's bring the temperature down! More water will freeze, growing the poles and lowering the ocean levels! If we're lucky, some of the poles might even become habitable!" Again, this is a terrible idea, causing

  • Destroying agriculture with snow, rather than heat,

  • Increase condensing of water vapor, possibly increasing the water level?

  • Potentially cause a new ice-age

  • Again, most humans would be pretty grumpy about the cold.

Then on the extreme ends of the spectrum "Freeze all the water, humans could live on the ice!" (probably a bad idea) or "Melt all the water, humans could live in the desert that used to be the ocean floor!" (Very clearly a terrible idea)

So here's my question: How bad are all of these ideas? I could be totally off, as I am not really a scientist. Assuming the technology exists, can earth pull off any of these? Is there any practical amount of climate change that could improve the world and make more land?

  • 1
    $\begingroup$ We can "change the temperature by a couple of degrees Celsius per year" ? Holy cow. Considering all our previous activity has risen the temperature by one degree Celsius in 120 years, changing by a couple degrees in one year is a very big deal. $\endgroup$ – Samuel Nov 6 '15 at 22:17
  • $\begingroup$ Frankly, those sound like terrible ideas. Altering the weather has serious consequences, as others have outlined. Since you can't freeze water into place (and not have it just melt again) what it comes down to is that you can't make that water "go away" short of blowing it away into space. That being said, "more land" will only be a temporary fix to overpopulation. It would be preferable to institute cultural/legal changes that would see people have only 1 child per family world-wide (or at least in the places that are most over-populated such as current-day China/India) $\endgroup$ – AndreiROM Nov 6 '15 at 22:31
  • $\begingroup$ Literally running out of land for people to live in doesn't make sense (people don't take up that much space, and we can build up very easily and just make mega-skyscrapers). Land needed for agriculture makes much more sense. But, not all agriculture has to be done on dry land. And as you point out, many changes we might be able to make would reduce rather than increase the amount of land suitable for agriculture. $\endgroup$ – sumelic Nov 7 '15 at 0:11
  • $\begingroup$ Some posit that we are already using climate change for good. Their position is that we are in an interglacial period of this iceage. Without manmade global warming we would have already started slipping back into a deep iceage. $\endgroup$ – Jim2B Nov 7 '15 at 4:34
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    $\begingroup$ Off topic, but I'd disagree with the notion that "everything in the world is better" because all the countries are "westernized." Please be careful about projecting a specific set of values onto people who may not want them. (Especially when the aforementioned poverty was essentially caused by previous generations of their self-proclaimed saviors swooping in to colonize them and steal their resources.) $\endgroup$ – Yumecosmos Jun 10 '16 at 14:33

Any drastic change, and by drastic I mean 1C - 2C change by 2050, has the potential to wreak havoc on agriculture, fishing and the global economy, not to mention wildlife.

Let's start with wildlife. Wildlife has adapted to the current climate over the last 10,000 years or so. Changing it even so slightly will cause species to migrate thus causing disruption of food chains which could lead to die offs.

Agriculture & fishing are directly related to that. Changes in temperatures will change the growing/migration patterns, type of crops you can grow, the type of pests common in each area will change, etc etc.

Finally changes in the temperatures can alter the salinity of the ocean, the prevailing winds, and/or ocean currents. A country that was once lush and green can become a desert and another can be flooded by rains leading to all sorts of political tensions.

Making land is not that beneficial anyway - there are huge swaths of land that are almost uninhabited, such as the mid west, Canada, Alaska, most of Russia, etc.

The negatives are simply too great, while the positives are slim at best.

  • 3
    $\begingroup$ I like how you say, "...not to mention wildlife. Let's start with wildlife..." $\endgroup$ – Samuel Nov 6 '15 at 22:20
  • $\begingroup$ The central parts of Australia... $\endgroup$ – a CVn Jun 10 '16 at 17:09

Warming the climate a few degrees has already been shown to be both possible and feasible for human civilization. If this was 1100-1400AD, we would be importing food from farms in Greenland and wine from Scotland. The reason we don't do that today is that it is too cold to farm in Greenland or grow grapes in Scotland, so the historical evidence for a warmer climate exists.

The evidence for a colder climate exists as well, since the average temperatures started to fall in the 1400's (causing the Vikings to abandon Greenland and eventually shifting wine making to France and Spain), climaxing with the Little Ice Age. At that point, crop failures were common, creating a great deal of instability in most nations. Many wars were happening at this time, driven by both the desire to gain potentially productive territories, and due to the logistical ease of transporting heavy equipment or marching armies across frozen waterways. The "Great Northern War" between Sweden and Russia (1700-1721) was one example in Europe, and in the Americas, the American Revolutionaries achieved some victories by being able to transport cannon across frozen rivers. (100 years later, Civil war generals did not have the same ability, since rivers were no longer so hard frozen in the same landscape).

  • $\begingroup$ Really interesting! Didn't know a lot of that... does this mean that anthropogenic climate change was already noticeable in the 1800s? Any thoughts on how much control we could reasonably expect to have, taking natural climate shifts into account? (I know this is old but I'm curious.) $\endgroup$ – Yumecosmos Jun 13 '16 at 14:45
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    $\begingroup$ Climate change is a naturally occurring cycle in the Earth's history. The climate has warmed and cooled repeatedly through history and it is thought that climate change caused the collapse of the Bronze age empires in 1200 BC. If the climate can change so dramatically long before there was any possible anthropological causes, then perhaps we are looking in the wrong place for the cause. $\endgroup$ – Thucydides Jun 13 '16 at 17:18
  • $\begingroup$ @Thucydides, excellent answer and comments. $\endgroup$ – Serban Tanasa Jun 13 '16 at 18:38
  • $\begingroup$ Well, I'm not informed enough to have much of an opinion on the causes of climate change. I tend to come down on the AGW side only because Lots of Smart People Say So. But I'll concede that if we aren't causing it in the first place maybe we can't control it as well as we think. (This is tantamount to blasphemy over on Sustainable Living, lol...) Maybe the answer is, even if climate control were practical in the short term, eventually natural changes could destroy most of civilization anyway? I wonder if more tech would help or make things worse? $\endgroup$ – Yumecosmos Jun 13 '16 at 19:50
  • $\begingroup$ Climate is a "complex, adaptive system", so attempts to control the climate will cause havoc. Outputs are not spatially or temporally connected to the inputs, and outputs don't scale linearly either. What actions you take today may not have an effect for centuries, and maybe not even in the location you carried them out. The glaciers on Mount Kilimanjaro started regenerating when reforestation in Kenya restored the local microclimate, to give an example. Restoring the glaciers will in turn affect rainfall patterns and the local water table... $\endgroup$ – Thucydides Jun 14 '16 at 2:12

Possible but unlikely, and extremely difficult to control. Say you want to warm Earth to turn tundra into fertile farmland.

  • How good is the topsoil in the newly temperate zone?
  • Could it be that you'll get plenty of swamps and mosquitoes instead of farms?
  • Will changes in rainfall mean that rivers burst their beds?

But the main issue is that there will be winners and losers from the change. As subarctic regions turn temperate, temperate regions turn subtropical. The people in the temperate regions are bound to complain, and that's where powerful nations are located. Consider how the US would feel if Canada wanted to heat them up just so Canada can become balmy.


Reality check? Let's do that!

  • Current cities population density, as reference List of cities proper by population is from 30000 people per square km to let say 1000 people per square km.
    I live in city with 3500 people per square km, and it's pretty ok, if move factories away it could be excellent. So let's stick with 1000 ppl per km2 as an easy and good number.

  • Food is different story, and depends on climate zone. Mild, cold sided mild regions produce 400 tonne per km2 per grow season in good case scenario. Usually there is not only a bit of cold, but not much light for plants to work with, that's main limiting factor for production, compared to regions where instead cold, heat is a problem. Vegetable to meat conversion ratio, depends, but is something around 1.5 for fish, 3-4 for meat. You have 3 kg weed so you get 2 kg fish or 1 kg meat.
    I may a bit off with that things, but it is something nearby.
    So let say we need 5 kg weed per day per person - to keep him full. And that limits population to 220 happy people per km2, some are fat so 200 people per km2, some are wasteful fit so let it be 100 people per km2.

So if we compare cities population density 30000-1000 ppl/km2 with food production needs 100 ppl/km2

  • there is no such problem where to live, there is a problem where to grow food.

Where to grow food?

Where is not a big problem, actually. It's more the question how to grow? For how many people?

As we wish to preserve or even maybe improve our current bio-environment, in some places, so let pretend we care about it. But as we have problem, someone have to pay, and die.

Between these opposites, we have solution - deserts. There is live and interesting live, but OP have problem, we have to sacrifice their environment. But as who cares - we will preserve them in zoo and any other methods we have.


For food production we need sunny desert, and Sahara with 9'000'000 km2 is obvious choice to discuss. It's not only one choice, but biggest one. Subtropical deserts in that list are 6'607'000 km2 combined.

Desert is good, because more sun, longer sun season. So if make all properly, it will give at least 3-4 times more weed then in mild-cold climate.
So just Sahara may give food for additional 2.5-3.5 * 1'000'000'000 people.

Yes, you have to work for it to happen. Use technology luke, build greenhouses, build water channel, recycle water, reuse water from humid air, use day-night temperature difference to your advantage, think think - it's doable.

Yes, it will affect earth climate in some way, but at least not so stupid and wasteful like heating some parts of earth.

So using only deserts we may feed +6'000'000'000 more people as it is now, at least, practically with old style technologies, combined with some current tech.

Real problem is?

Real problem is energy. If we have energy sources, stack 10 store, 100 store Sahara desert greenhouse Inc building. There is plenty of useful sand to use. Not so simple, CO2 may drop significantly - that will be some limitation factor, but we have plenty fossil fuel to burn. Amount of available Carbon may be a problem. Heat dissipation may be a problem, or may not be a problem - depends on energy source, thermonuclear reaction theoretically are way more efficient then combustion cycle. Carnot cycle temperature of the hot reservoir is millions of K, cold reservoir thousands for K.


Space is also question of energy, if we have much and cheap, cheap enough to heat earth, so we do space, cheap and in huge quantities, even if technology of getting in to space did't moved a single step forward and is as it is now.

Terra-forming earth

  • Terra-forming the earth. 70% of the surface of the earth is water. If we can bring that number down, we will have more room. How do we go about this?

Strongly not recommended. Until you will know it enough, to not to loose information, but make information. Ocean is place to live for many creatures. I do not care about their lives, human lives are more important, but loosing so much genetic information, bio-chemistry, bio-diversity, connection to our past - just loosing all that information, which is result of hundred millions years of collection of it, testing it, which is source for us to learn - it's a shame. Problem is, to make that information again, we have to spend thousands of years, in space stage, using way way more energy then we use now. And some bits of information may safe us or help to answer on questions. Waste thousands years of our future civilization, just because we are to lazy spend 10-20 year now - what sort of thinking is that. It's not just solving our current problems in better and high quality way, it's about surviving our species in next 10-20k years.

There is better and easier way to solve our problems - Space.

No matter how much you terra-form The Planet, you will end with same problem, very soon.

Space is our answer and our future home.

  • $\begingroup$ What is "kkk people"? $\endgroup$ – JDługosz Jun 12 '16 at 22:58
  • $\begingroup$ 1kkk = 1'000'000'000 - sorta shorter and there is difference in Long and short scales where 10^9 have different names - it's kinda more defined that way $\endgroup$ – MolbOrg Jun 13 '16 at 13:35
  • $\begingroup$ More defined? Only to those who have heard of it; otherwise it scans as an unidentified typo that may or may not affect the meaning. The first page of Google results is nothing but klu klux klan and one story about Trump. No mention of it in this context, so it must not be common at all in English. $\endgroup$ – JDługosz Jun 13 '16 at 19:48
  • $\begingroup$ New Scientist uses the short scale, which threw me at first because I thought it was supoosed to be British like the spelling and other idioms. Horizon (the tv show) also uses Billion in the way familiar to me here in Texas. In fact, I've not seen any Long Scale since I was a kid. $\endgroup$ – JDługosz Jun 13 '16 at 19:51
  • $\begingroup$ Ah, looking at your link, the short scale was adopted oficially in Britain in 1974. Short is pretty much it in English now, but Long is used (in translation) in Portugese, Spanish, and French. I might guess that you speak French, as the spelling billion is the same. But your use of thousands separator suggests Swiss or intentionally trying to use an unambiguous symbol (on my tablet I can't check the unicode code point used, but that inspires me to add U+2396 to my custom keyboard on my main machine). $\endgroup$ – JDługosz Jun 13 '16 at 20:04

Is the world's present temperature the optimum temperature to maximize the amount of food the world can produce, and simultaneously maximize human comfort, and simultaneously preserve other forms of life, and simultaneously be the absolute best for every other factor you can think of? I'd guess not, but even figuring out how you would calculate that would be awfully difficult.

It may well be that someday people will have the technology to alter the climate in beneficial ways. But I think that would be more complicated than just raising or lowering the global average temperature. I'd imagine it would involve redistributing water supplies, altering prevailing winds, etc.

There's also the problem that things that benefit one group of people might harm another. Like increasing world temperatures a degree or two is probably good for people who live in Norway, but not so good for people who live in Libya. Or even in a single place: Reducing the amount of snow might be great news for farmers and loggers, but bad news for people who run ski resorts. Etc.

  • $\begingroup$ And then the farmers get grumpy because the reduced amount of snow in the winter results in less land irrigation during the spring, which is bound to impact them somehow... $\endgroup$ – a CVn Jun 10 '16 at 17:12

Increased CO2 causes plants to use water more efficiently. Crops yields of some grains will increase, others will decrease, thus mitigating the effects of climate change.

See https://wattsupwiththat.com/2016/04/20/columbia-university-begrudgingly-admits-the-benefits-of-co2-on-crops/

Based on the current biomass of these crops, water-use efficiency would rise an average of 27 percent in wheat; 18 percent in soybeans; 13 percent in maize; and 10 percent in rice. All things considered, the study projects that average yields of current rain-fed wheat areas (mostly located in higher latitudes including the United States, Canada and Europe), might go up by almost 10 percent, while consumption of water would go down a corresponding amount. On the other hand, average yields of irrigated wheat, which account for much of India and China’s production, could decline by 4 percent. Maize, according to the new projections, would still be a loser most everywhere, even with higher water efficiency; yields would go down about 8.5 percent. The study is less conclusive on the overall effects on rice and soybean yield.

The deserts are greening as a result of increased CO2:


The analysis also showed that elevated carbon dioxide significantly enhanced soil water levels in drylands more so than it did in non-drylands, with soil water content increasing by 9 percent in non-drylands compared to 17 percent in drylands, Wang said.

There is a debate over whether warmer winters will save more lives normally lost to cold exposure than the warmer summers will kill due to higher temperatures. See https://wattsupwiththat.com/2015/06/18/study-global-warming-wont-reduce-winter-deaths/ in which the models say warmer winters won't save many lives but the actual data (a chart) shows that excess deaths between winter and summer have been steadily declining.


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