What are some big ramifications that result from seemingly small changes?

I’m looking for changes that appear to be rather benign, but over time, might result in very real broad changes in an environment. For instance, what changes happen if the average temperature of a lake is raised or lowered by one degree?

On other example is fluoride being added to water. From what I understand, it had a huge result in dental health for the populations where it was added. The change can either be due to nature or man. Intentional or not.

Thoughts?

Wouldn’t a lot of it depend on how much time elapses? Pretty small changes in the Cretaceous could’ve had immense ramifications for the present, as Homer Simpson found out to his great regret in Treehouse of Horror V.

Like a butterfly flapping her wings?

This isn’t an environmental issue, --more a medical issue:
Adding iodine to salt is a small change that has major ramifcations on public health.

From wiki:
“iodisation of salt may be the world’s simplest and most cost-effective measure available to improve health, only costing US$0.05 per person per year”

It only takes a miniscule amount of iodine (a couple of spoonfulls in a ton of salt), to protect the entire population of a country from major health problems.

“Spell My Name with An S” http://en.wikipedia.org/wiki/Spell_My_Name_with_an_S

Niagara falls will eventually disappear into the northern edge of Lake Erie. They flow over soft limestone that is slowly being eroded away several feet each year (or they would if flow reductions for hydropower didn’t reduce them to less than a foot each year).

Another great example is the DDT usage back in the 60’s-70’s (it was banned well before I was born). The amounts any single creature was exposed to were fairly small and benign (except to the bugs it was intended to kill). However, predators higher up the food chain would consume multiple affected animals concentrating the dosage to a poisonous level.

No, that’s more of an incident that may set off a series of chain reactions. I’m looking more for a slight change in environment and a broad change it might generate. Here’s one that’s more what I’m looking for. Since The Biggest Loser has become part of common TV fare, people have become more attuned to fitness and the sales of healthier options at fast food restaurants goes up significantly.

Well, there’s the whole elimination of lead from gasoline and the correlation to reduced crime thing. I’m not sure I buy it, but the the correlation exists.

Switching to CFL or LED bulbs.

According to Energy Star, if 20 million standard incandescent bulbs were replaced with LED bulbs, it would save $118 million dollars in energy costs each year, and prevent greenhouse gas emissions equivalent to 150,000 cars/year.

I hate CFLs and LED bulbs though.

But that is not necessarily cause and effect. It is more likely that the popularity of both are a result of a healthier attitude among people in general.

That’s true. I guess there’s no way of telling. But I doubt Subway would be continuing with the whole healthier fare thing if Jared didn’t work or the association with TBL wasn’t generating results.

Perhaps you’re right, magellan01, but Subway was founded by a group of doctors on the premise of healthy food before Jared’s weight loss came into the picture.

Really? I didn’t know that. Nice little morsel of fact there.

Well, morsel of something! Doctors Associates isn’t a bunch of doctors.

Perhaps closer to the OP - the range of a tropical cyclone (aka hurricane, typhoon) is critically dependant upon sea surface temperature. They won’t form if the temperature of the sea surface is below 26.5C. They can travel over colder water once formed, but cold water will tend to weaken or extinguish them (well drop them back to a simple low pressure system.)

Ocean currents cause temperature differences on a global scale, and this controls the range of tropical cyclones significantly. A good example is the concentration and range across the two sides of the North American continent. Nice pic from Wikpedia The North Atlantic Conveyor (aka Gulf Stream) is responsible for the higher sea surface temperatures up the Atlantic coast, and with it, it brings the hurricanes.

A single degree change in sea surface temperature can extend the range of tropical cyclones by hundreds of kilometres, bringing cities or even countries into their path when before they never or very rarely occurred.

The North Atlantic Conveyor is itself a great example of how a very small change could have massive knock on effects. Its circulation is critically dependant upon the sinking of cold more salty water in the North Atlantic. If this sinking effect stopped, the circulation would shut down. What is worrying is that it is not clear how the circulation starts again. So one scenario has a large scale ice melt diluting the salt water, reducing its density, and shutting down the entire Gulf Stream. It is generally accepted that Europe is dependant upon the Gulf Stream for its climate - and so shutting down the flow could bring about massive drops in temperature, large scale crop failures across Europe, and little short of eco-political calamity on a planetary scale. On the up side, hurricanes would probably be less of a problem on the east coast of the US.

At about $10 per bulb, that’s a savings of $118 million at a cost of about $200 million…

Whoops, missed the “per year”. Sorry.