This is what you didn't actually answer: What is the correct average global temperature? What year/time period average should we use to determine the correct temperature? What happened to the global climate before this most recent trend? Is global warming bad or good? (Maybe is not a good answer) And what caused the previous temperature change? And the one before that? And what about global warming on Mars? If there is global warming and it is bad, how much would it cost man to stop/reverse this trend? Or will the trend reverse on its own? And would the money be better spent on other things? You made comments of each group of questions, but didn't actually answer them.
You too are making the same type of unwarranted assumptions about scientists. I know based on their own claims that the information is only available for a limited amount of time. From there they extrapolate. That's good for speculation, but not for unequivocal determinations. Or to convince me and looks like a lot of other folks based on response of the masses.
I'll try. Average temperature? No one has done enough of a study to say with any factual references. The closest thing that can be done is a form of standard testing. Which while certain to give a range, could not determine if the planet was healthy at the time. The best developed snapshot will only be regional speculation at best. Period of Speculation? Interesting question. Would need to be debated as there would be no real way of actually determining anything more than a range. No period certain (annual) determinations are certified at this time. Most dating is done to periods using the term "about. Recent Trend? Hmm, do you mean 200 year allotments? 1,000 year ranges, or more? A standard dating for this would still need to be set. That or you must accept ranges and abouts as reference points. Bad Or Good? For man, beast, insect or planet? Yet to be determined. Could be that man would do better in a slightly warmer climate. There is no current evidence to prove either way is beneficial. Mars? Ok, I give! You win. There is no real undeniable proof that warmer temperatures will not be accounted for by nature. It just might be that the food belt might have to move to better more fertile areas. We just might have to start growing crops in different areas. For shame!
Some of the questions can only be properly answer with appropriate scientific background knowledge. Most questions don't have a clear cut yes or no answer. Are you really interested? That will bore everyone to death. I'll try to answer the first two questions together because they are the same nature. If you're not bored and want more then I can try the others. What is the correct average global temperature? What year/time period average should we use to determine the correct temperature? The short answer is that there is not a uniquely defined average global temperature. This is similar to the question "what is the correct index for the market average?" Just because there are dozens of market indices doesn't mean that you won't know whether the market went up or down in the past 10 years. Likewise, there are many ways to examine whether the global temperatures went up or down in the past decade or in the past century. You can use daily close, weekly close, or even monthly close to measure whether the market is going up or down. Over the period of many years, whether you use daily close or monthly close matters very little. But you have to be consistent. You cannot use daily close for one year, and monthly close for the next. Same goes for the global temperature. You can take the high of the year or the low of the year, or the average temperature on same 12 days of each year. But you cannot compare temperatures in January to temperatures in June. Take a look at this figure below It gives three sets of reconstructed historical temperatures. These were data using different methods. They are like three different marke averages. At any given year the difference between the three sets can be huge. These differences can have many causes. Part of that may be related to the accuracy or reliability of the particular method. Part of that could be due to random events happened locally at the place where the data was recorded. But the nature of random events are such that they do not influence the overall trend. Indeed, the overall trend of all three curves is the same. Correction: There are actually 5 curves. But 2 of them don't go back as far as the other three. That may have to do with the limitations of the method used or the availability of the data. So the question should be reframed as "If we don't have a unique standard for an average global temperature, how do we know that it's going up?" The answer to that question is, we compare apples to apples and oranges to oranges. If all of them show the temperature going up, then we have "global warming."
Don't spread false science here. What you claim is clearly false. The information is available for far longer period than you can possibly imagine. If you don't know something, don't make it apparent to everyone.
Your own chart shows 2000 years ago I guess. So that's when the planet started huh? And damn if almost 1000 years ago the temperatures look quite a bit high on your chart there. Do you see it? What caused that surge? Must have been the SUV's? And again, this is all about speculated temps. None of the data claims to be infallible or actual. I'll be happy to show you from your own posted data that they only speculate. Your youthful exuberance is not helping here. You are no more an authority than anyone else. Cut and paste away youngin'!
Don't equate your own ignorance with scientific knowledge. Just because you don't know of anyone who has done a study doesn't mean no one has done "enough of a study." Your "standard testing" is silly. Just shows that you have no clue how to get temperature records of distant past.
Say there was a flood 100,000 years ago, we don't know what caused it. Say there is a flood today when a man made dam breaks. Flood is flood. The consequences are the same, what is in the path of the flood is drowned. Flood is flood, warming is warming....
When one saw skid marks on the road, one's pretty sure that a vehicle had been there. Those temperature records were the skid marks. They are as certain as logic. That's what science is based on. If you think logic is "speculation," that's your choice.