# How to have a landmass the size of Great Britain have almost every single climate

I'm creating a continent which will be about the size of Great Britain (250.000 km2) and I'm creating it under certain constraints.:

• This continent was very powerful once upon a time, but now it is completely devastated by something (working on it). The only people remaining are living in a town in the coast, some barbaric groups on the continental side and some mercs that were sent to this continent to raid and/or protect areas that were previously valuable.
• The town is being rebuilt as the time of the story goes, but still under attack by the barbarians.

Now, with that said, I wanted a variety of climates on it. So far I wanted a swamp, two different forests, a mountain area and.... A cold area with snow....

I could make the other 4 areas work together, Panama is basically that on a lot smaller scale. However I can't conceive the notion of having snow only on a certain area. Think of it as Westeros, which you have the always cold North and always snowing beyond the wall. I wanted to bring that "Always snowing" feature to my world without having to create an Africa-sized continent. Any ideas how and/or why you would have snow in that specific area?

I initially thought about altitude, having something about 4000 meters above the ground level and if I'm far enough from the Equator that would cause to have snow most of the year if not all around the year...

• Welcome to WorldBuilding.SE! I've removed your final paragraph in order to focus on your main question; asking for suggestions for continent-blighting events on top of that would have made this too broad. I think we've had questions in the past about world-spanning catastrophes; have a look through the site and see if you can find anything, and if not, feel free to ask a separate question about what could devastate a Great Britain-sized continent. – F1Krazy Aug 6 at 9:14
• Welcome on WorldBuilding.SE! Please clarify your I initially thought about altitude. Why did you decline this decision? If it's good enough, please clarify what you are asking for? P.S. IMHO altitude and mountains is great answer. – ADS Aug 6 at 9:46
• What about New Zealand? – SZCZERZO KŁY Aug 6 at 10:42
• @ADS Because altitude causes other problems like lack of air and different pressures. I went to Peru once and that altitude change was really hard on us, so since my world will have adventurers exploring from the city until the snowy areas, I figured mountain would cause an unnecessary disadvantage on top of the harsh weather – NickNunes Aug 6 at 11:41
• Mount Kilimanjaro is almost exactly on the Equator (all right, 3° south), occupies an area much smaller than Great Britain, and exhibits almost all types of climate, from savannah to rainforest to heatherland to alpine desert to quasi-artic, complete with vertical walls of ice. – AlexP Aug 6 at 13:25

Altitude.

The big island of Hawaii has just about every climate type. Discussed here: Could an island on Earth with these climate types exist?

It is a combination of the giant central mountain intercepting rain clouds (and thus a dry side and a wet side) and the ability of higher altitude to simulate higher latitude. Higher is colder.

Put your land in the tropics. It is a giant shield volcano. The lowlands will be wet and hot or dry and hot. As you ascend you traverse strips of different ecosystems right up to tundra like frozen conditions on the top.

Then if you want a caldera you can replicate what you have on the outside on the inside on the way down.

• Yep. I've seen snowdrifts above my head atop Mauna Kea. Then, note that the northeast is very wet, while the southwest is very dry. The mountains cast a major "rain shadow". I've taken an afternoon walk that started in rain forest, went through desert, and then back to rain forest. And I haven't actually spent much time on the Big Island. – John Doty Aug 6 at 21:14

# Make it long

Chile is almost like that, except it is attached to a larger land mass and it has 3x the land area of UK. But since it spans a lot of latitudes, it naturally has polar climate at the south and deserts on its northmost areas, with some tropical pockets in between. It also has the world's second highest mountain range to the East, so it has a lot of snow in all latitudes all year-round.

To cover a lot of different climates, an island the width of Chile but going from the latitudes that span from Edinburgh to Madrid would be only half as long as Chile and could cover a lot of different climates.

## Model it after New Zealand

Speaking from personal experience, you can go from glacial heights to fjords to tidal flats to forest to swamps (or at least mucky farmland) within the same day, sometimes even maintaining vision of the previous terrain. Closest thing to Neverland in Robin William's Hook I've seen.

There are a number of geographical features that contribute to this, including latitude, altitude, ocean currents, prevailing winds, and volcanic / geothermal activity.

### Cape Reinga

The Gulf Stream

I don't know if you are British or have visited Britain but we already have much of what you are asking for. There are mountains in the Highlands of Scotland and Scottish days are shorter and, in general colder, than the South of England. Manchester is reputed to have constant rain - surely an exaggeration. We have plenty of forests - just pick the largest. https://en.wikipedia.org/wiki/List_of_forests_in_the_United_Kingdom

The nearest to a swamp is the Norfolk Broads

In the Middle Ages the local monasteries began to excavate the peatlands as a turbary business, selling fuel to Norwich and Great Yarmouth. Norwich Cathedral took 320,000 tonnes of peat a year. Then the sea levels began to rise, and the pits began to flood. Despite the construction of windpumps and dykes, the flooding continued and resulted in the typical Broads landscape of today, with its reedbeds, grazing marshes and wet woodland. https://en.wikipedia.org/wiki/The_Broads

A critical factor keeping the UK warm however is the Gulf Stream.

Logan Botanic Garden in Galloway is able to grow plants that would not survive elsewhere in Scotland. This is because Galloway has a mild climate due to the Gulf Stream. The Gulf Stream is a flow of warm seawater which passes the west coast of Scotland and brings warmer weather. Logan is seldom affected by frost or snow. https://www.bbc.co.uk/bitesize/clips/zffr87h

If the shape of the land masses on your version of Britain (or even some actual climatic catastrophe that diverts such a warm current IRL around the UK) prevents the proximity of the warm current at the North and brings it closer at the south will make "Scotland" like North Westeros and the South of "England" like the Mediterranean.

NOTE

See excellent comments by @Joe Bloggs, @Tonny and others below.

• Thanks to the Gulf Stream some parts of Britain are even subtropical in climate. – Joe Bloggs Aug 6 at 10:34
• @Joe Bloggs - If you want to comment with a little more detail about which areas, and a link to an article, I'll add this fact to my answer and credit you for it. – chasly - supports Monica Aug 6 at 10:40
• The one that springs immediately to mind is Ventnor on the Isle of Wight, which sits just off the coast of the south of England (and subsequently is bathed in the warm glow of the Gulf Stream). I’m sure there are others (I think there’s a tea plantation in Cornwall that’s sometimes suitably warm?) – Joe Bloggs Aug 6 at 11:25
• Slightly pull Lands End a bit more to the west and make it a bit longer. That would channel more warm water to the Channel and less into the Irish Sea. Makes the Channel Coast almost Mediterranean. And raise Scotland north of Loch Ness into a 1500-2000 meter high plateau with some even higher peaks. That would make that area sub-arctic with glaciers and chances of snowfall almost all year round. – Tonny Aug 6 at 11:26
• Mine would actually be upside down in this case. Never been to Britain, but my initial thought was something the size of the State of Sao Paulo (Brazil) and an island so it's far away from the rest of the civilization. Turns out Britain fits the bill. Now I wanted to make the South cold and the north warm. I also noticed that there is a sort of desert southeast of England in Dungeness caused by the mountains blocking the rain from the North Atlantic. How realistic would it be if I had a desert akin to North Africa's in the Island? Or that would be impossible? – NickNunes Aug 6 at 11:53

This is s seven part answer.

I suggest that you make your land mass long and narrow and extend almost directly north and south.

And also make your planet as small as possible consistent with having a breathable atmosphere.

And maybe make the planet have a greater axial tilt than the Earth does.

You can also make different parts of your land mass have different climates due to different altitudes.

You can also use warm and cold sea currents to heat and cool different parts of your land mass.

Part One: Stretch the Land Mass North and South.

Earth has a polar radius of 6,356.8 kilometers or 3,949.9 miles. It thus has a polar circumference of about 39,940.9 kilometers or 24,817.932 miles. The distance from the equator to the North Pole or South Pole is thus a quarter of its polar circumference, or 9,985.22 kilometers, or 6,204.483 miles.

On the planet Earth extending a landmass 9,985.22 kilometers, or 6,204.483 miles, from the equator to one of the poles will put different parts of the landmass in every climate zone which depends on latitude. Other factors may influence how wet or dry various parts of the landmass are.

The size of the land mass is specified as 250,000 square kilometers. Assuming that it is an artificial perfect north-south rectangle it would be 25.037 kilometers or 15.557 miles wide.

But on Earth a landmass which extends from the tropic zone to the polar zone only has to extend through the entire temperate zone and a little bit more more both north and south. It might stretch from a little bit closer to the Equator than the Tropic of Cancer or the Tropic of Capricorn to a little bit farther than the Arctic Circle or the Antarctic circle to have small regions in the tropical zone and in the polar zone, while most of it will have various temperate climates.

On Earth the Tropic of Cancer and the Tropic of Capricorn are 23.43661 degrees of latitude from the Equator, and the Arctic Circle and the Antarctic circle are about 66.5 degrees from the equator. So the separation between the Tropic of Cancer and the Arctic circle is about 43.1 degrees of latitude.

Assuming that your continent is an artificial rectangle oriented north-south with 10 percent above the Arctic Circle and 10 percent below the Tropic of Cancer, it would extend over a total of 53.875 degrees of Latitude, which is 0.1496 of the full polar circumference of Earth. Since the polar circumference of Earth is 39,940.9 kilometers, if your landmass was an artificial perfect north-south rectangle it would extend for about 5,983.2496 kilometers north to south, and if it had a total area of 250,000 square kilometers it would be 41.7833 kilometers or 25.9629 miles wide.

Part two: Shrink the Planet.

On a smaller but still habitable planet, your land mass could extend to a lesser north-south distance while stretching between the equivalents of the Tropic of Cancer and the Arctic Circle. So how small could a planet be to be able to retain a breathable atmosphere for humans or for intelligent beings with similar environmental requirements.

Well, we should look at what Habitable Planets for Man, Stephen H. Dole, 1964, 2007, has to say.

https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf[1]

On page 53 Dole calculates the mass, size, etc. of a planet with a surface gravity of 1.5 times that of Earth, 1.5 g, considering that to be the upper limit of a planet habitable for humans. On page 54 Dole calculates the lower limit of a planet with an atmosphere with enough oxygen for humans.

To prevent atomic oxygen from escaping rapidly from the upper layers of its atmosphere, the planet's escape velocity must be of the order of five times the root-mean-square velocity of the oxygen atoms in the exosphere...

.., then the escape velocity of the smallest planet capable of retaining atomic oxygen may be as low as 6.25 kilometers per second (5 x 1.25). Going back to figure 9, this may be seen to correspond to a planet having a mass of 0.195 Earth mass, a radius of 0.63 Earth radius, and a surface gravity of 0.49 g. Under the above assumptions, such a planet could theoretically hold an oxygen-rich atmosphere, but it would probably be much too small to produce one, as will be shown below.

Dole then discusses the minimum size planet necessary to produce an oxygen-rich atmosphere. He calculates two different minimum sizes, one of 0.25 Earth mass, and one of 0.57 Earth mass, and decides that the first one is too small and the second too large.

...With 0.25 being too low and o.57 being too high, the appropriate mass for the smallest habitable planet must be between these figures, somewhere in the vicinity of 0.4 Earth mass.

Since it is not possible to obtain a more precise determination of the minimum mass of a habitable planet, for our purposes the value of 0.4 Earth mass will be adopted as the lower limit of mass. This corresponds to a planet having a radius of 0.78 Earth radius and a surface gravity of 0.68 g.

So on a planet with a radius of 0.78 Earth radius a land mass stretching 53.875 degrees from north to south would have a length of 4,666.9346 kilometers. If it was an artificial perfect rectangle it would have an east west width of 53.5683 kilometers or 33.2858 miles.

But maybe Dole was wrong, maybe a planet with less than 0.4 Earth mass can produce an oxygen rich atmosphere, possibly even a planet with only 0.195 Earth mass, which should be enough mass to retain an oxygen rich atmosphere. Or possibly an advanced civilization has terraformed that planet in the past, giving it an oxygen rich atmosphere.

So on a planet with mass of 0.195 Earth mass and a radius of 0.63 Earth radius a land mass stretching 53.875 degrees from north to south would have a length of 3,769.4472 kilometers. If it was an artificial perfect rectangle it would have an east west width of 66.3227 kilometers or 41.2110 miles.

I once read, in a novel by Arthur C. Clarke, possibly in collaboration with another writer, a mention that the Moon had been given an Earth like atmosphere. That atmosphere was retained by a layer of nanobots which held on to each other and bounced back any air particles on escape vectors.

If that or some other method of retaining an artificial atmosphere is possible, your planet could be a tiny planet that was once terraformed to be habitable and settled with people, who have reverted to a less advanced state. We can hope they will rebuild their civilization before any action on their part is needed to maintain the habitability of their world.

Thus if your planet is much smaller than 0.195 Earth mass, and its atmosphere is artificially produced and retained, your land mass could be even less than 3,769.4472 kilometers from north to south to reach all the climate zones and thus could be even more than 66.3227 kilometers from east to west.

Part Three: Increase the Axial Tilt of the Planet.

In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane.1 It differs from orbital inclination.

At an obliquity of 0 degrees, the two axes point in the same direction; i.e., the rotational axis is perpendicular to the orbital plane. Earth's obliquity oscillates between 22.1 and 24.5 degrees2 on a 41,000-year cycle. Based on a continuously updated formula, Earth's mean obliquity is currently 23°26′11.8″ (or 23.43661°) and decreasing.

https://en.wikipedia.org/wiki/Axial_tilt[2]

So Earth's axial tilt is about 23.5 degrees, and the Tropics of Cancer and Capricorn are about 23.5 degrees from the Equator, and the Arctic and Antarctic Circles are about 23.5 degrees from the North and South Poles.

So if Earth had an axial tilt of 30 degrees, the temperate zones between the tropics and the polar circles would be only 30 degrees wide.

So if Earth had an axial tilt of 33.25 degrees, the temperate zones between the tropics and the polar circles would be only 23.5 degrees wide.

So if Earth had an axial tilt of 35 degrees, the temperate zones between the tropics and the polar circles would be only 20 degrees wide.

So if Earth had an axial tilt of 40 degrees, the temperate zones between the tropics and the polar circles would be only 10 degrees wide.

In our solar system, the axial tilts of various planets and a couple of other bodies vary between 0.03 degrees for Mercury and 82.23 degrees for Uranus. So it would certainly be possible for your planet to have a larger axial tilt than Earth does.

Part Four: Stretch You Land Mass North to South, and Shrink Your Planet, and Give Your Planet a Larger Axial Tilt.

Combining all three methods of getting your land mass to include all the latitude based climate zones will produce a land mass that is elongated north and south but maybe not too much to be believable. And multiplying its surface area of 250,000 square kilometers a few times would help keep it's elongated shape within plausibility.

Part Five: Climate Zones based on Altitude.

You may have heard of the Hemingway story "The Snows of Kilmanjaro" and the 1952 movie based on it. And here is a link to a photo showing Kilmanjaro and some of that snow.

https://en.wikipedia.org/wiki/Mount_Kilimanjaro#/media/File:Mount_Kilimanjaro.jpg[3]

Mount Kilmanjaro is only 03°04′33″ south of the Equator, but it has snows at the top.

Here is a list of the climate zones of Mount Kilmanjaro:

Climate zones

Bushland / Lower Slope:, 800 m – 1,800 m (2,600 ft – 5,900 ft);

Rainforest Zone: 1,800 m – 2,800 m (5,900 ft – 9,200 ft);

Heather / Moorland: 2,800 m – 4,000 m (9,200 ft – 13,100 ft);

Alpine Desert Zone: 4,000 m – 5,000 m (13,100 ft– 16,400 ft);

Arctic Zone: 5,000 m – 5,895 m (16,400 ft – 19,300 ft).

https://en.wikipedia.org/wiki/Mount_Kilimanjaro#Climate_zones[4]

And here is a link to a picture of Mount Chimborazo, whose peak is the point on Earth farthest from the center of the Earth.

What country is Chimborazo in? Ecuador, a country named after the Equator. Chimborazo is only 01 degrees, 28 minutes, 09 seconds south of the Equator.

At high enough altitudes, places can be snow covered all year even at the equator.

So possibly your land mass doesn't have to stretch a long way from north to south to have many different climates. It might be in the tropics but have high mountains and high plateaus so that some high parts have snow all year just a few miles from lush tropical vegetation at the sea side.

And if prevailing winds dump a lot of moisture on one side the land mass, large parts of the other side might be in the rain shadows of mountains and plateaus and be cold, temperate, and hot deserts without much or any rainfall.

Part Six: Climate Zones Based on Sea Currents.

Other answers have already pointed out examples of lands such as Britain that are warmed by having warm waters flow from the tropics to their shows in currents like the Gulf Stream.

Assume that your land mass is mostly or all in a temperate zone. So the waters around it normally have the same temperatutes as other ocean waters in the temperate zone.

But a large warm current like the Gulf stream comes from closer to the Equator and reaches the southwestern corner of the land mass and warms it significantly. A large island to the west of the land mass block the warm current and prevents it from going north, so the seas northwest of that island are the normal temperatures for that latitude.

But a large cold current like the Labrador Current comes from the Arctic and reaches the northeastern corner of the land mass and cools it significantly. A large island to the east of the land mass block the warm current and prevents it from going north, so the seas southeast of that island are the normal temperatures for that latitude.

So the ocean waters northwest and southeast of the land mass are the same temperatures as other waters in that latitude, but the southwestern waters are much warmer, and the northeastern waters are much colder, and the temperatures of those water bodies affect the temperature of the land mass, especially if if is a long narrow land mass.

Or if it is in the southern hemisphere the warm current could come from the north and the cold current from the south.

And of course the different altitudes of the different parts of the land mass will affect their climates.

Part Seven: Conclusion.

So the ways you can make a land mass as small as Great Britain have diverse climates include making it stretch a long way north and south, making the planet it is on smaller than Earth, making its planet have a larger axial tilt than Earth, giving the land mass a high range of altitudes, and having the land mass reached by warm and by cold currents.

A landmass the size of Great Britain which has a) swamp, b) two types of forest and c) snowy areas?

You're describing Great Britain which all of these things and more. We have several types of forest -- including actual rainforest -- and more marshes, swamps, bogs, sloughs and wetlands than you can shake a soggy stick at. Snowfields are in Scotland at altitude, especially in the Caingorms which can remain even in summer.

As a bonus, it was also once very powerful but has now gone into something of a decline.

Technology.

It could be something similar to the system that creates Zootopia's districts.

This continent was very powerful once upon a time, but now it is completely devastated by something (working on it)

The machines creating the climate could be very large industrial machines that have at least partially survived the disaster, but can no longer be controlled by the island's inhabitants. They would need to be powered by some renewable resource, or maybe a large, self maintaining nuclear reactor that hasn't yet exhausted its resources. Some or all of the climates may not be the original intention of the machines, but instead could be caused by damaged / malfunctioning machinery. For instance the swamp could be caused by damaged pipes for hot water / steam. Depending on the time that has passed since the disaster, nature could be in various stages of blending with the machinery.