Often the graphs depicting the earth's historical temperature, the time axis extends well over couple of centuries. Also there are few that extends over thousands of years.
I wonder to what degree the measurement inaccuracies are taken into account while using these charts to communicate the ongoing climate change. Its a valid question that older temperature measurement suffer a higher error compared to modern day's methods.
Even the feared 2.5°C temperature rise over the industrial revolution time is a minute variation over centuries. To what degree has the climate models taken into account these measurement errors into account? (In short, the question is basically from a climate change sceptic that goes like - "Thermometers have gotten better and we are just measuring the true temperature and it's not that the world is warming up. So how can we accept climate change/global warming?")