How is popular culture so divided on man-made climate change if it’s such an established phenomenon?
There are several factors involved in this. First, “popular culture” is not divided if we look at it world wide, most people in most nations accept climate change science and scientific consensus. The US is the exception, and not in a good way, but in an ignorant way.
Why the US popular culture is so divided is multi-factorial, it includes missinformation campains from big pollution industries (coal and oil, but not exclusively) using many approaches to influence public opinions. But also bad science communication, scientific illiteracy of the public and complexity of the subject.
What is the evidence for man-made climate change?
What does the evidence suggest it’s the mechanism of man-made climate change?
There is a vast body of scientific literature going back decades, but let’s try a simplification in form of a logical argument. (credit to logicofscience)
Premise 1: CO2 traps heat and is largely responsible for the earth’s climate.
That is a scientific fact.
Premise 2: We have greatly increased the CO2 in the atmosphere.
That is a scientific fact.
Premise 3: When you increase something that traps heat, you trap more heat.
Has been experimentally shown many times and is intuitively obvious.
Conclusion: Therefore, we are causing the climate to change.
This conclusion follows necessarily from the premises. CO2 traps heat, more CO2 traps more heat, we have nearly doubled the CO2 in the atmosphere, therefore the earth is trapping more heat. This is irrefutable. It’s not opinion, it’s fact. Unless you can discredit one of these premises or show that a logical fallacy has been committed, you MUST accept the conclusion.
Please bear in mind that although this reasoning is sufficient, it is by far not the only way scientists think about this problem.
There are tons of parameters we measure (sea levels, ocean acidification, water temperatures, radiation reflection, ice cap shrinking, land temperatures…) and built mathematical models to predict how these parameters will influence climate; and so far we are unable to find a model that can explain what we measure without considering human contribution. Yet when we add human contribution (CO2), these models can very accurately predict what we measure.
In fact, one of the most influencial papers goes back to 1967 and its predictions from 50 years ago are accurately describing todays measurements. These scientists were right about human caused climate change half a century ago.
What is the limit of our knowledge about climate change?
At this point there is no serious debate in the science community about whether climate change is real and human made or not. The consensus is that it is real and human made, and there is no evidence that casts any reasonable doubt.
However, what is more unclear is the extend of problems that come with this climate change, how it will effect the shape of our planet, vegetation, weather and agriculture, just to name a few. The prognoses go from “not so good” to “catastrophic”.
Furthermore, it is unclear what is the best way to hold climate change, new technologies or policies are in many cases not flashed out, thus science cannot do all the heavy lifting.
What science can do well is predict what is going to happen if we do not change course and sometimes give suggestions on what the most promising course of action is if we do not want to face the predicted misery.
What are the ethical implications if we are able to demonstrate causality of our existence on climate change?
The causality is demonstrated satisfyingly. Science is not responsible to make judgement calls, it just describes what is.
It is up to us humans to work with the facts presented by science. To base our decisions on the evidence given and to discuss amongst another what future we want to live in.
Science can help us find courses of action that will help us reach our goals, yet we still have to choose these goals first. If our goal is to keep the planet somewhat inhabitable for all the species (animals/plants etc) we have grown accustomed to, we have to stop artificially and thoughtlessly messing up our climate. Simple as that.
I hope this answer was helpful!