Here are the facts
There is this thing that exists called the Greenhouse effect, which traps heat in the atmosphere.
CO2 and other Greenhouse gases enhance this effect, which causes more heat to be trapped, heating up the atmosphere. This causes the climate to change, the ice caps to melt and the sea levels to rise.
Naturally, most CO2 is absorbed by the earth through "sinks", however we are now emitting more CO2 than the sinks can take in. This means more CO2 goes into the atmosphere and traps more heat.
And the evidence shows this is what is happening.
I think it is absolutely certain that climate change exists and the democratic stance on it is right. For years it has been proven by hundreds, even thousands of studies, researches and factual analysis of the temperature tendencies years before us, and with some logic, it can apply to years in the future too.
As a science student and a geography student I can say without a shadow of a doubt that global warming is leading to climate change. All the evidence points towards it, the ice core analysis, even recent temperature changes. Perhaps the consistent denial of this comes from dispute among the scientific community. Well as the son of a scientist I can tell you that the people who disagree with climate change in the scientific community tend to also be members of scientology. Take what you want from that.
I am as certain as Bernie Sanders that climate change exist because the world's climate has definitely changed since the industrial revolution. There are measurable effects such as the depletion of the ozone layer, reduction of summer storms in the Atlantic, and rising heat indexes in many places such as the Middle East.
Bernie simply claimed that "the debate is over." There is plenty of evidence to refute significant man made climate change. I went to the NASA website to see their argument for climate change, and they have a lot of what looks like convincing evidence on their home page:
They start with what looks like a hockey stick graph of worldwide CO2 levels for the last 650,000 years. Given that no scientist has ever. I repeat, ever been able to conclusively link CO2 as the cause of global warming, this data is irrelevant. Another important consideration is a primary source of CO2 emissions: the human body. The graph shows a big spike from about the 1700's to today, with the biggest notable spike being from 1950 to present day, a period through which the world population nearly tripled... So that graph offers no scientific weight, just "shock value."
You then scroll down to read about sea level rise. Non-science savvy readers may automatically attribute this to warming... But NASA conveniently leaves out the fact that a known cause for rising sea levels is an increase in gases in the ocean, and is actually linked to causing the oceans to warm, not as a result of the ocean's warming. They also fail to openly admit that the sea levels over the last million years have changed dramatically, varying by up to 100 meters, which they will discretely admit if you take the "quiz" that's right under that claim.
I could say more, but I would just be plagiarizing, so let me just refer you to the link where I found all of the refutation data and let you decide for yourself.
If climate change exists, man isn't responsible. Man only wishes that he could control nature. Nature is big. Man is small. Humans shouldn't pollute but that doesn't mean that we're so big that we control when it rains. People that preach climate change only want to stifle the free economy. It's politics, not science.