20. Mass extinctions we may never know about

"An asteroid/comet impact crator was recently discovered in Greenland last year (Nov 2018) due to melting ice caps in the area.

This crator could be as recent as 12,000 years ago and if that's true it completely changes our understanding of 1) how frequently mass extinction events happen and 2) the history of human civilization.

All of a sudden global flood myths, ancient landmarks (Pyramids, Sphinx), and other mysteries line up with a global population getting wiped out and thousands of years of rebuilding/lost knowledge."

Throwaway4the6ix

19. It's all a simulation... maybe?

"The basic nature of reality is waves of probabilities.

A your chair is only your chair because it is probable that it exists in that form.

We also very likely could be living within a computer simulation. The universe is either simulated or just happens to look very much like a simulated universe."

JulieNaaiers

18. Mosquitos cause too many problems

"Entomologist here. While not 'new' (maybe ongoing is a better term) new mosquito-borne diseases. Remember Zika when it showed up? It's far from the only horrible disease you can get from certain mosquitoes that's often a virus with no treatment with high fatality or severe effects. 'New' ones can still pop up like Zika did, which is scary enough, but certain species of mosquito like Aedes aegypti that are invasive to many countries tend to carry these human diseases."

where_are_the_grapes

17. Zombies are unlikely but possible

"The plot of the last of us could actually happen. Given that there could be a cordyceps discovered that could lock onto and spread throughout humans. This would essentially turn every host into a brain dead zombie. The Likelihood of this happening is about 1/1000000 though."

To_coolio_for_school

16. The heat is rising

"As the Earth warms carbon dioxide that's traped in ice and in the ocean will be released into the atmosphere. This can start a positive feed back loop where the increased heat releases more carbon and the carbon increases the heat which in turn release more carbon. We could be getting very close to this point"

casual-captain

15. Get vaccinated

"80% of males and females between 16-25 are infected with the papilloma virus (HPV) that is a cause for several types of cancer, especially of the uterus."

Cybx

14. Something to think about

"Something I find scary to think about is what hasn't been discovered or hypothesized. The universe is most likely finite. If it has an edge, what's beyond that edge? The universe had a birth. What was before that birth? What is nothingness? What causes nothingness to become everything?"

C9_Edegus

13. This seems to be coming true...

"The impending water wars. Not as fun as it sounds."

purpleleafemoji269

"Not even figuratively, there will be literal wars fought over clean water."

andretwic

12. As if the quality of healthcare isn't bad enough

"Earth has a finite amount of helium, and we are starting to run out. At some point, it will need to be rationed. MRI machines need liquid helium to cool its superconducting magnets.

So what will probably happen is many hospitals will no longer be able to offer an MRI, and knowing the system in the US, this means hospitals in poor areas first. A lot of people are going to die or suffer from undiagnosed diseases/disorders."

Jinzot

11. Avoid teflon pots and pans

"Teflon is poison and because we all have used teflon things, we all now have that poison in our blood and we can't get rid of it. Now we have bigger risks of getting diseases, cancer for example"

Patu1234

10. This doesn't sound deadly and would be cool to witness

"The star Betelgeuse in Orion may be about to go supernova. We've known it's going to go supernova soon (that's astronomy soon as in could be tomorrow or in 200 years). Betelgeuse is a variable star, so it gets brighter or dimmer all the time, but it just got dimmer than we've ever seen it before.

No one's 100% what's going on. If Betelgeuse does go supernova, all of our satellites and stuff will be fine, the solar wind will protect us. The main problem is we'll have no night for a while (maybe weeks?) so it'll really throw animals off."

fredmcgee33

9. Practice safe sex

"'Super gonorrhoea' is resistant to the vast majority of strong antibiotics, including fluoroquinolones and macrolides. N. gonorrhoeae is mutating all the time to resist antibiotic effects. There have been multiple reports of super gonorrhoea in Australia, England, etc."

manlikerealities

8. I honestly had to Google "replication crisis"

"The 'replication crisis' in psychology (though the problem occurs in many other fields, too).

Many studies aren't publishing sufficient information by which to conduct a replication study. Many studies play fast and loose with statistical analysis. Many times you're getting obvious cases of p-hacking or HARKing (hypothesis after results known) which are both big no-nos for reputable science."

0xD153A53

7. I hate bugs but they're so important

"The world has 70% less insects on average than it did 40 years ago. We really are coming up on our silent spring.

For the people saying there are less pests, those arent the ones we're worried about. Insect pollinators are vital to so many crops, we could be facing serious problems with certain food supplies soon. In recent years China has had issues with apple and pear crops to the point where some regions have had to pollinate crops by hand. Also, insects form lower blocks of many food webs, and their disappearance will spell trouble for higher trophic levels."

deep_brainal

6. Great, something else to worry about

"Abdominal aortic aneurysm. It's basically an aneurysm that happens in the big artery in the middle of the abdomen. It's fine and is usually asymptomatic but when it ruptures, a patient loses all their blood within a short period of time. The scary part is that it usually is diagnosed by accident due to annual checkups for something else. Anyone can have the disease, but especially people with Marfan syndrome, smoking, hypertensive, and hyperlipidemic."

DrFaust1729

5. Take care of your ears

"Known link between untreated hearing loss and cognitive decline i.e. dementia.

ETA: key word is untreated. If you previously had normal hearing and it started slipping, please see an ENT and audiologist... If you have had hearing loss since childhood, you're not one of the ones I'm worried about. You have either learned sign language to keep you from being isolated due to your hearing loss and/or you have learned how to use hearing aids/cochlear implants to keep you from being isolated due to your hearing loss.

The link is really between communication and cognition, not the physical ability to hear. It's just that in people who previously had normal hearing, if they don't do anything it will impair their communication and in turn affect their cognition."

bonbons2006

4. The island of nuclear horrors

"Not a scientist but I will still take the time to mention something that scares me I only found about a month ago, and I don't think a lot of people are aware of but probably should be. Back in 1946 to 58, the US tested 60 nuclear weapons on the Marshall Islands and buried the nuclear leftover waste and soil in a 30 ft deep cavern 'sealing' it with a concrete dome...the dome is cracking and now it's leaking into the ocean and surprise surprise it's not fixing itself, and the people responsible are essentially ignoring it or saying it is not their problem. Imagine Chernobyl but bigger and in the Ocean."

Chemsicals

3. Another reason to fear climate change

"There are ancient microbes lying dormant in glaciers. As climate change progresses and these glaciers melt, it is possible that we will be exposed to ancient diseases for which we will have no immunity."

Bright_Page

2. That researcher is a hero

"A genetically modified bacteria that could have possibly wiped out a lot of crops and plant life was almost commercially released into the environment. Fortunately, a researcher decided to do one more test in the lab before it was used in production. Found out it killed all the wheat seedlings, and she destroyed the remaining stock of it."

ksiyoto

1. Man eating fruits

"Pineapples have an enzyme that digests protein. So whenever you eat a pineapple, it is eating you back"

caz0011666