This isn't a trick question. I'm just trying to get an idea of what you know.
I know that almost every person I know accepts the total population of the world when it is given. How do they know the population number is accurate to within a couple of million? Sure, a lot of countries will perform a census, but the vast majority don't. Especially those in poorer, more populated countries where most of the population growth happens. So how do they predict it? Modelling. Just the same way they predict man-made climate change. I find it interesting. I'm confident a shitload of people who don't believe that man is contributing to climate change due to the methods used to prove it (modelling), do believe in the approximation given of the population of the Earth using said method (modelling).
OK.. I was wrong.. You have a different angle.. So let's address that..
Before the 1930s or so -- world population estimates SUCKED as badly as "Global Mean Anomaly Surface Temperature"... No computers, no satellites, no reporting from the MAJORITY of the globe...
That got fixed for BOTH to some extent today...
So the issue with MOST DENIERS is NOT "Is the Earth experiencing a rather brief and mild warming -- but the REAL ISSUE is -- How fucking disastrous will it be in 2100..
If I ask you what the world population is GONNA BE in 2100 -- you'd suck almost as badly as estimating the World temperature anomaly in 2100...
To wit, there was the 1970s "The Population Bomb" scare that influenced even me into being an environmentalist. THOSE predictions are clearly bogus just 15 or 25 years after the public was made to pee it's pants about breeding explosions in Africa/Asia... Because the THEORY sucked.. The pushers of this crap could not forsee the leveling effect of DECREASING POVERTY and advances in farming..
SO -- here you are peeing your pants about a 1DegC increase in "GMASTemperature" over about 80 years. With no ACCURATE measure of climate temperature over the past 10,000 years for THE WHOLE GLOBE that even APPROACHES that accuracy or time resolution..
And -- the forecasts since this circus train left the station for 2100 have been CONSTANTLY REVISED DOWN as the models predicting ACCELERATED warning and Doomsday temp threshholds have YET to be measured since the 1980s when all this EXAGGERATED hysteria began..
I'm concerned a bit.. NOT peeing my pants about another billion people or another 1DegC (give or take) simply because
1) We have NO ancient temperature records of the world that even APPROACH 1 DegC over 80 years accuracy for thousands of years with 50 or 100 year time resolution.. So we DO NOT KNOW what 100 year period thermal surface equilibrium looks like to compare...
2) I reject ONLY the more catastrophic versions of GW/CC models that postulate the warming effect will accelerate due to the prevalence of "mostly positive" feedbacks in the modeling... Or a "trigger temperature" beyond which the planet (AND the poor "Person of the Year" Greta Thunberg) is doomed...
The critical constants in GW modeling like "climate sensitivity" have been revised DOWN SO MUCH since 1980s --- that my position, based on the basic Physics and Chemistry of the atmosphere, that the warming will NEVER APPROACH even today's modeling of the 2100 temperature... And year after year, these downwards revisions are validating what I've learned and observed...