Well, first off, natural ice ages/natural climate changes/weather out your window have nothing to do with the man-made CO2 issue and its current and future effect on the planet.
The fundamental question today is whether human activity that causes greenhouse gases is causing an unnatural global warming or not. Scientifically educated people who examine this stuff, from all over the world, with different biases and different politics and different agendas and different sources of money and every other variable, have reached an overwhelming consensus based on 1000's of investigations and experiments (not a few corrupt and invalid ones), and after years of school and work using mathematics that most of us don't even know exists, they conclude with the body of evidence that almost surely human activity is vastly accelerating global warming and waiting longer before doing something about it is a very bad bet. They also know about ice ages and weather and all the other stuff to take into consideration when producing hypotheses, don't you think that's the whole point of science?
And, by the way, the industrial age (and the industrialized meat industry) came long after the Middle Ages. Anectodal stories about other times when it was hotter have nothing to do with the problem being addressed by those who understand these things.
How come nobody complains about how corrupt and stupid and foolish scientists are (even with their actual errors along the way) when they use the same process of investigation, discovery, experimentation and validation to figure out how to cure diseases, or get to the moon, or repair birth defects, or make better cars and planes and engines and computers and satellites and drugs and bomb detectors and tissue regeneration and contraceptives and MRI machines?