If you research tempersture records, you'll find we actually know a lot about tenperatures going back centuries.
And that shows how much of a ******* idiot you are. Because the truth is that we have no such thing. What we have is a series of records over the past 150ish years, with degrading accuracy as you go back further in time. Considering the fact that current AGW theory relies on extrapolating long term trends based off extremely small variances, temperature records from the beginning of the 20th century are effectively worthless.
Any decent science source will explain how that works.
You don't actually know how it works, do you? Let me explain it to you....
What we have is a temperature record that goes back roughly 150 years. The accuracy of that record effectively degrades the further back you go, because advances in technology have refined and enhanced the precision by which we can measure temperature. Of course, differences of a few tenths of a degree are largely irrelevant in the grand scheme of things. But in terms of tracking trends over time which exist on scales less than a degree, those inaccuracies become of utmost importance.
Everything before the "official" record is an extrapolation. These extrapolations are achieved by hypothesizing various proxies and correlating data, and then attempting to extrapolate those secondary metrics. One of the most well known of those is the hypothesized correlation between "average" temperature and atmospheric CO2 content. Based on this assumption, scientists will look for ways to estimate atmospheric CO2 content at historic times, and from there will estimate average temperature based on previously calculated correlations between the two. Perhaps you've heard of studies relating to ice cores?
The problem in all of this is that it all begs its own question. You're using an assumption that there is current global warming with certain causes, and then using those calculations to estimate historic temperatures, and then turning around and using those calculations as evidence that warming has occurred. Logically, this is equivalent of assuming that global warming is caused by increased variance in human genetics across the global population, assigning correlative markers based on the past few decades, estimating the rate of increasing complexity of human genetics, then scraping some ancient neanderthal bones to test them for genetic variance, estimating global temperatures based on the hypothesis that human genetic variability is correlated with temperature, and finally concluding that the temperature record of 100,000 years ago confirms that the earth is currently getting warmer and that it correlates precisely with increased human genetic variability.
Again - how is it that you don't know what everyone else learned a decade ago?
A decade ago, you learned that the world was warming, because someone told you that. Two decades ago I learned how to apply the scientific method to study things and how to apply logic to information to extrapolate sound conclusions. Bet you didn't know that it wasn't too long ago that "the science is settled" about the impending glacial period that the Earth would fall into during our lifetime.
Part of the problem is that when it comes to climate science people are taught the conclusions, and very little effort is put into teaching people to actually do the leg work to justify those conclusions. Yes, you learned a decade ago that the world is warming, and that we know this because we know the temperatures from thousands of years ago. So now, all these climate scientists out there tell everyone that the world is warming. Because that's what they were taught in school. They do all this research that tracks how much the world is warming, because that's where the grant money comes to pay their bills. And when they finish tracking the warming, they tell us again that the world is warming. Because that is what they were taught in school. They "adjust" the old temperature record to better align with changes in atmospheric CO2 content, because that's what they were taught in school.
