Do climate change skeptics have alternate models?
Yes and no.When skeptics means scientists publishing solid papers, yes they do have models, but those models have varying inputs, assumptions and outputs and almost entirely agree in general, but disagree in specifics. In other words, skepticism is around narrow points and percentages of impact within the scientific discussion, not around upending the paradigm.As an example, there are four major studies of antarctic ice cover. Three show a decrease in total ice. One shows a slight increase with an expectation of decrease in future. There’s scientific disagreement which is being assessed by the major study groups and related researchers. Weighing the validity of the methodologies, assumptions and measuring techniques requires skepticism and independent thought.When skeptics means deniers, all they have are napkin calculations, ‘common’ sense and some bad Excel spreadsheets. No denier has a robust supercomputing set of models for any of their alternative fact explanations. An assessment of the papers which denied climate change was caused by man found a collection of data errors, logic errors and zero consensus or consilience on alternative causes.On the same example of antarctic ice, deniers cherry pick the single study that they like and completely ignore the rest, pretending that they don’t exist and that there is no reason to doubt. The link provided earlier to a Quora question on the topic shows exactly that process.Like my content? Help it spread via Patreon. Get confidential consulting via OnFrontiers. Email me if you’d like me to write for you.
Is there an estimate of how many humans have lived in the past 200,000 years?
40% that have lived on Earth are living today, so that would 17 billion people out of what I estimate. The population in past history has been more smaller than today's.