Is this a joke? Dunno, grade school? Corroborated by a multitude of sources, some of which are on Wikipedia, and should be general knowledge. Did you not learn about this in grade school?
It’s not a joke. What are you talking about? 56 million years ago (Paleocene-Eocene Thermal Maximum, the last time temperatures were six degrees higher? Or, back when earth was a molten rock of lava? That’s completely irrelevant to this discussion. Temperatures haven’t been higher than a degree since the last ice age (see the excellent relevant xkcd: https://www.climatecentral.org/news/climate-change-xkcd-comi...). Rapid anthropogenic global warming does not bode well for human civilization. That doesn’t mean life on earth or humans as a species will be wiped out, but you can’t say “earth was hotter when the dinosaurs were around, so, no problem”
Didn't say no problem, only that the map of the original post I replied to is shit. Which it is. There's no reason to believe everything south of Siberia and Canada will be a desert.
Climate science is based on past CO2 levels and uses the fossil record of foliage to estimate temperatures. Not even the most dire predictions claim the earth will be mostly desert in 100 years. There will be flooding and some desertification, but many regions will also become greener.
Even NASA has observed that the earth is greener today than 40 years ago.
Some things are common enough knowledge that asking for a source is disingenuous. Everyone should know the earth was once warmer and went through various cooling periods.
It's like asking for a source to prove the sky is blue or that the earth is round...
This community claims to be one of educated professionals, yet somehow there's comments questioning things that are literally common knowledge and if somehow they don't know, can't spend 2 seconds to google it? Instead write "Source?". It's intellectually lazy as hell.
The problem with things that "everyone knows" is they are often hyper simplified abstractions that form useful models but are not appropriate to discussions of anything specific or for shaping policy. Everyone "knows" Pluto is farther than Neptune (except when it isn't[0]), traits are passed via dna (except when they aren't[1]), sex matches with gender (except it doesn't[2]).
Sure the earth was warmer in the past, it was also colder, it was also a molten hellscape. Trying to relate a grade schooler's understanding of geologic time to specific climate models seems to be far more intellectually lazy than asking for a source so people can put your very vague claims into context.
>Some things are common enough knowledge that asking for a source is disingenuous.
Yes. But then we invented science and "common knowledge" was proven ignorant time and time again.
>It's like asking for a source to prove the sky is blue or that the earth is round...
Hardly. I can't look out my window and see what the temperature was thousands of years ago.
>This community claims to be one of educated professionals
You're claiming that, not 'the community.'
What is intellectually lazy is not providing information that verifies your claims, and instead preferring to debate the social circumstances of an internet discussion. You're not obligated to provide a source. You don't have to do it. But don't think you're somehow more intellectually honest or hardworking because you refuse to.
If 2 seconds of googling solves this problem, then you should have probably just done that rather than arguing about whether you should need to.
As an aside, the reason we know that CO2 affects earth's temperature is the same reason we know what kind of vegetation existed during that same time period. Because of observations in the fossil record.
