Can one nation purposefully, inconspicuously, cause global warming?

Question

The People's Dominion of North Kadana is an arctic isolationist dictatorship, with lots of territory but it is all barren frozen tundra. Their plan: heat up the world by a few degrees, making their permafrost melt and turn into arable land, so that their nation becomes more productive whilst their southerly neighbours are hit with flooding, desertification and tornadoes (don't tell the Supreme Leader that molten permafrost will not be fertile for generations due to the lack of topsoil, he is wiser than all of us and surely knows better).

The Supreme Leader has faith that his line will stay in charge for at least three generations, so we have a hundred years to play with. To make it simple, assume constant 2020's tech throughout that period. Can a single, highly motivated nation warm up the Earth by three degrees Celsius (a conservative estimate for the required temperature increase to melt Greenland) in that time period?

Assume a generally climate-apathetic global community, that is already warming up the planet a bit by themselves (they would heat it up by one degree Celsius, Kadana wants three more). It shouldn't be too hard to imagine. However, if Kadana is highly visibly wrecking the planet, the other countries may very well seize the opportunity to make it a scapegoat, and possibly even go to war.

So there must be an element of subterfuge to the operation, with reasonable excuses for everything they do that draws the attention of foreign nations. That means, building some polluting factories is okay (economic development), exploding stuff on their own territory is okay (military tests), but releasing vast quantities of artificial greenhouse gases is less feasible. Such a gas can be detected, and traced back to its point of origin, ratting them out. It's fine if many people suspect Kadana has a hand in the global warming, but there should be reasonable alternative explanations.

Other factoids:

• Kadana has about fifty million people, most of whom have poor living circumstances, but the military is well-funded and warming up the planet is the primary military goal. Assume an annual budget of around 5 billion USD for this operation, plus a virtually unlimited domestic supply of unskilled labour.
• There are many foreign military bases around Kadana, and even trade with its closest ally is kept in check. So another factor is minimising the amount physical material that needs to leave the country. That also applies to sending stuff into space.
• Kadana has some allies on the world stage, who may be amenable to hosting mysterious factories, but none of them wish to heat up the planet. They too must be kept in the dark. However, don't worry about Kadanan defectors; few would believe this ridiculous plan without hard evidence.

What is the best way Kadana could heat up the planet?

Answer 1

as user535733 mentions:
Those deep ocean methane clathrates...

Invest in a new "GREEN" power company, that uses the thermal potential of deep ocean water to generate power. It's real. Not very cost effective, and maintenance is a pain, but it is real. and... one of the effects is to drastically increase deep-ocean (including ocean floor) temperatures.
The methane clathrates are very sensitive to local temperature changes. Boosting the local temperature of the seawater by even just 3C is enough to trigger a phase change in the methane ice, releasing the gas. Which, incidentally, stirs up the ocean currents more, leading to more water mixing, and more release. These events can form chain-reactions of quite monumental scope.

And, as it happens to be, some of the very best locations for OTEC power generation are located right next to some of the world's largest methane clathrate deposits! Just look at that motherlode a bit SSE of Okinawa, Japan.

Potential temperature differential for OTEC power

Known locations of large methane clathrate deposits.

Best of all, your country can (almost) honestly say "NOO! We are the GOOD GUYS!! See, we are working on zero-carbon power generation, for all humanity" hehehe-snerk!
(Picture of premier-president Lord Admiral-General Haffaz Ajamhinadad Osama Hussein Aladeen, Supreme Leader of the Republic of Wadiya.)

((Do not take seriously!))

Answer 2

Dump methane into the atmosphere. Lots of it.

Dig a lot of "water" wells that "happen" to tap methane pockets.

Have your Naval Engineers find ways to release methane trapped in undersea clathrates. Then you can have your submarines nefariously release methane belonging to other countries.

Encourage agricultural and waste management practices for plausible reasons...that happen to encourage anaerobic methane production. Rice paddies and cows can make a lot of methane.

Your shills and toadies and apologists outside the country should engage in a campaign of misdirection, focusing world attention on secondary effects and less-impactful causes so you can dump as much methane as possible for as long as possible. They should also try to encourage other nations to adopt your "smart" or "sustainable" or whatever-buzzword-works agricultural practices.

If attention is drawn to your releases, time them to coincide with seasonal changes and storms to confuse the source and add deniability...or not. You're a sovereign country, your serfs will fight to the death to preserve their way of life, and you got a few nukes stashed away. Who's the punk now?

Answer 3

In recent years, North Kadana has begun investing heavily in a few key industries:

• magnesium refining
• insulated glass
• high voltage electronics manufacturing
• if possible, semiconductor manufacturing (probably not, that is likely beyond the economic capabilities of such a poor arctic dictatorship)

All of these industries have on thing in common: they all use sulfur hexaflouride (sf6), a greenhouse gas 23,900 times more potent than CO2. The current annual output of sf6 is 8,100 tons, equivalent to 100 million cars. North Kadana's goal is to bump up those numbers as much as possible. The equivalent amount of sf6 would be around 1.8 million tons of sf6 to match the entire global anthropogenic output of CO2 (43 billion tons). This is probably possible to achieve.

So we have a technical method, but the remaining challenge is disperse it without anybody knowing it was you. You need three things:

1. A method to release it without it being traced back to you

2. A scapegoat to take the blame

3. An alibi

For #1, user535733 had the right idea with submarines. Your nationalized SF6 plant safely stores the gas underground...right next to your secret submarine tunnel. Load the gas onboard, send the subs into the ocean undetected, and now they can go anywhere in the world without outside powers snooping.

For #2, you need another country to blame for this. Find a region of the sea with lots of competing interests and people to blame -- the Persian Gulf, the South China Sea, etc. This is where you will release your gas, slowly, from the submarines. When satellites and climate watchdogs notice these crazy new SF6 spikes around these ocean hotspots, watch as the competing nations begin trying to pin this on each other. It doesn't matter who exactly takes the fall, as long as there is doubt.

For #3, you need to fabricate a reason why SF6 is showing up in huge spikes in the atmosphere now. Otherwise, it's possible a global crackdown on the gas's use and production might set its sights on your nation. This is the hardest step, but the best way I can think of is to use a concerted misinformation campaign. Spread conspiracy theories, fake news, and fan the flames of confusion in major countries, based on whichever theories the players in #2 come up with. Meanwhile, join as many climate-activism treaties and conferences as possible as a nation. Set and fulfill goals on decarbonization, invest in green energy sources, and you will hopefully avoid detection by other nations who don't see you as a major player in climate change.