I once watched a show where they took a 6 grade test from back in the early 1900's ( I think it was 6 grade or there about's ) and gave it to present day college students and it was amazing the college student couldn't pass the test.
Honestly, i'm not entirely sure i could pass that test, though if you could link it in i could at least attempt it
This goes both ways though, although i have a masters degree in chemisry, i'd probably fail the top level highschool chemistry exam if i attempted to take it. Not that my answers would be off by that much, but i could certainly fail to correct for something, or correct for something i'm not supposed to rendering the numerical result off by a bit.
As for the big scaremongery: i'm not really sure how much of that is science and how much is politics. Before global warming was an issue, we had acid rain. This acid rain would destroy plant life, and possibly even buildings (concrete is eroded by acidic water over time).
Somehow the acid rain story disappeared entirely with the news about global warming. As far as i know reductions in SO2 and NOx emissions were made to deal with the acid rain problem, but i've never seen anything in mainstream news about how succesful (or not) those efforts actually were.
As far as 'versions of truth' go: there is some scientific merit behind some of them. If you look at something like global warming and sea level rise you can go for the effects of the worst possible outcome, the median or average, or the lowest possible risk scenario.
And then come the media with the need to report things as shockingly as possible to attract attention. This is what changes the perception of an ocean level rise of 1 meter in 2100 to something like 'potentially' 10 meters by next sunday. What they do is combine the worst possible scenario (all ice melts) with an unrealistic time line to create panic (or, realistically ad revenue).
This does not help anything. Telling the general public to stop burning candles because they'll otherwise be flooded next week is not realistic. Ignoring ocean level rise and failing to increase protection by waterworks is unwise too. Living in a country largely below sea level (at significant cost) could make you more aware of what and what not to believe. Oh, and we've not been flooded yet!