If you can find a study that even attempts to answer any part of the above question I'll put salt and pepper on the study and eat it.
Just so we're clear, consider this graphic from an Energy Central article titled "Warming and Pipelines," which goes NOWHERE NEAR discussing any part of my question:
One would think that after seeing 93.4% they'd say, 'Say, what factors might be causing oceans to get warmer?' But they don't ask the question because they already know the answer: Manmade greenhouse gases.
As to studies of heat transfer to land from land-buried pipelines and cables -- as with the waterways, I have seen some highly technical studies about heat transfer posted to the internet. But alas they too are no help to getting even a rough idea of the extent to which pipelines heat the ground. Again, I'll eat any such study if it turns out I missed it after I plugged many scores of keyword strings into internet search engines.
So while there are studies explaining that heat transfers to waterways and land occur from pipelines, etc., climate scientists clearly have no idea how much heat transfer occurs as an average, and how and whether this affects the allover temperature of waterways and land. Yet if the intention is truly to save the planet from 'excessive' warming, I'd think the scientists would leave no stone unturned because of the critical importance of offsets.
In other words, there is a big difference between completely, mostly and much when it comes to assigning blame for overheating of Earth's surface. If manmade greenhouse gases are completely to blame, then the human race should continue in a one-pointed focus on reducing the gases. If there are additional factors, then it makes sense to go for any relatively low-hanging fruit while combating the gases.
For example, there are ways to reduce heat loss from pipelines -- a serious problem for oil companies. I saw one study where a company was working on developing electrical heating 'packets' to attach to pipelines all along their route. This to keep the oil nice and toasty warm as it goes through the pipelines so it doesn't turn to gel as it travels further from the heated source. Another approach engineers are working on is better insulation for the pipelines. This approach would also work for underwater pipelines.
As for the oceangoing vessels, I'm thinking in particular about mega-container ships and the supertankers that carry LNG and petroleum. And of course there are giant naval vessels and cruise ships, although I think their number is dwarfed by the container ships that have been crisscrossing oceans and seas since the 1980s.
It's possible that some if not much of the heat these vessels generate dissipates into the air. But again I have no idea. Yet if they do transfer significant heat in total to the waterways -- could that be a factor in ocean warming?
As to the heat generated by submarines and undersea cables in total, again, I can't try to guess; I can't even find how much heat transfer there is, just from one submarine or cable.
Are science and math sufficiently evolved to tackle the kind of question I'm asking? How much science does it take to stick a thermometer in the ground? Do a reading when oil is running through the pipeline on land and when it isn't. Then you could get fancy and walk a little distance from the pipeline to take another temperature reading all right Pundita that's enough; the reader gets the picture. Then you could ramp it into rocket science by taking temperature readings at times of the year when the ground is colder and warmer. Pundita, enough.
As to oceans -- I'd assume there are ocean thermometers but can't satellites be used to spot heat signatures underwater?
I'd start with an inland sea that has a number of oil pipelines running through it. That might produce interesting underwater heat signatures.
Of course variables would need to be factored in, but the goal would be a ballpark figure, not to cover every blip in a variable; this in order to get an idea of how much warmer the sea is with pipelines going at full blast. Of course seas aren't an ocean but a relatively small experiment could set up a research paradigm to study heat transfers in largest waters.
None of the above is to argue that manmade greenhouse gases aren't a problem; ocean acidification from an uptake of increased CO2 would alone be hugely problematical. But the question I've asked is just one of several that climate science has ignored in its hyperfocus on greenhouse gases.
When one considers that carbon emissions-spewing nations such as China and India have been moving the goal posts by setting up coal plants in other nations, it's naive to hope that driving down the emissions will alone save humanity from any self-induced climate calamities.
Putting the horse in front of the cart means studying all human actions that are possibly warming Earth's climate in a significant way, and noting any convergences and cumulative effects amongst these actions. In this, climate science has so far failed, in my view.