A major fissure eruption in SE Iceland.

Since the Norse Settlement there have been two; the Eldgjá eruption in 939 CE, and the Lakagigur eruption of 1783-4. Although Eldgjá was larger, the massive Laki eruption is better documented. It created local devastation, crop failures, and poisoned grazing animals and people. Half of the farm animals and twenty percent of Icelanders died. Things got so bad that the Danish government considered evacuating the entire island.

We now know the Laki plume of sulfur dioxide spread across the Northern Hemisphere. In the UK, it killed tens of thousands of people; elsewhere there were crop failures and poisonous fogs. The climate went berserk with a series of bitterly cold winters that caused the Mississippi to freeze in New Orleans and ice floes in the Gulf of Mexico. Rains in the Nile Valley and the monsoon in India and China failed leading to famine. Total death toll in the 18th Century - anything up to 1 million people.

An often overlooked disaster is the rapid decline of insects, especially pollinators such as bees. Although bee extinction is not immediate, it could have a significant impact on global food resources, ecosystems and biodiversity. Without these pollinators, many crops would fail, leading to food shortages and economic disruption. But this important issue has not received enough attention.

The ocean fisheries will collapse. Yesterday's trash species and today's featured "catch of the day," will be tomorrow's memory. Harvesting is occurring at unsustainable rates while environmental degradation is steadily reducing habitat and forage ranges.

For many people in developed nations, fish is one option, among many, for protein. For most people in developing nations, it is the cheapest and most accessible option. When it's gone, there will be catastrophic socio political and economic upheavals.

The Cascadia Subduction Zone off the coast of the Pacific Northwest will rip again. Depending on the specifics, it will be a really bad day, or an utterly catastrophic day, for the PNW. That will be from the earthquake itself and from the subsequent tsunami. It rips every several hundred years and the last one was in the year 1700.

AMOC, (Atlantic Meridional Overturning Circulation), slowing/halting. Melting of northern latitude glaciers are effectively hosing the North Atlantic Ocean with cold fresh water, disrupting the global conveyor belt in the ocean which redistributes heat across the planet. If AMOC slows enough, (which we’re looking at happening within decades, not centuries), global weather patterns will shift entirely. Western Europe will freeze, the southern hemisphere will retain much more heat, sea level rise will increase significantly, the oceans will lose some of their capacity to sequester CO2 which in turn increases atmospheric warming, melting of glaciers, etc., generating a positive feedback loop. We really don’t want AMOC to stop.

Most large scaling farming practices are non renewable. We need to continuously find new ways to farm things or we won’t be able to grow food anywhere near the scale we do now.

The amount of methane and other gasses that are bubbling up from the arctic is a lot more than previously thought. Greenhouse gasses on steroids.

Antibiotic resistance and the emergence not only of superbugs, but pan drug resistant bacteria. Reports say that by 2050, deaths from infections caused by superbugs will be one of the leading causes of mortality. Regrettably, bacteria are evolving faster than we can develop new antibiotics, and the indiscriminate use of antibiotics in the dairy and poultry industries is only worsening the situation.

The real issue is the speed at which we are developing new antibiotics and the willingness to develop them. Other drugs are more profitable, (e.g. chemotherapy), let us hope that new development in phage therapies or new antibiotics will be available before it is too late.

People don't really know, but coffee beans are on their way to extinction.

Epochalypse.

In 2038, the old Unix/Linux systems that have physical 32 bit time registers are going to “run out of time.” Kind of like the Y2K bug, but this is a physical memory issue. Hopefully all the old systems will be swapped out by then.

Most people don’t realize how fragile the US, and other nations’ food systems are. There are very few smaller family farms, everything is corporate owned. If anything disrupts the distribution channels, (a truckers strike, warehouse house strike), most super markets will be out of fresh food in 3-4 days. And when that starts the panic of buying canned food will clear the rest.

A powerful earthquake along the New Madrid Fault in Missouri.

Human medication / illicit substances are flowing into water systems via sewage and becoming a real threat to our wildlife.

It's been written about, but no one I speak to, even in my hospital, realizes it. A very worrying doctor shortage. Not only were there simply more boomers, but they're also aging out and will now need more intensive medical care.

Microplastics. It's being found everywhere in our environment and is already being discovered in the blood/tissues of wildlife and humans. Scientists don't even know what the long term health effects of this will be.

I’ve worked with water for the majority of my professional career. If the average American had any idea how uneducated and stupid your average water operator is, they’d be shocked. The disaster is already happening. Water and wastewater districts all over the country are lying about what’s in the products coming out of their plants.

The true disease scare is in fungal infections as they are becoming harder and harder to catch, easier to misdiagnose, and there are some fungal infections spreading right now that can live on surfaces for months and are not susceptible to most anti fungal. Look up candida auris.

Folks have known for a while that in the coming decades Florida's municipal fresh water infrastructure will fail due to salt water intrusion. It's already started in certain places and large metros like Miami are trying to curb it.

As far as global pandemics go, COVID was not nearly as devastating as it could have been. Keep all aspects of COVID the same, but increase its lethality. For context, the bubonic plague killed 80% of those who became infected. If something with the same transmissibility and lethality as the bubonic plague manifested today...especially now that we've seen how people respond to pandemic controls, we'd be finished.

Deep fakes. You may think you can tell the difference now, but as it gets more sophisticated you're not going to be any better at identifying it than your grandparents. What will the world be like when we can't trust anything we see or hear? What will happen when anyone can make a video of you saying anything they want?

There is going to be a serious disaster when you get very high humidity and temperature, it's called a wet bulb event. Death rates in that city will be very high.

"The Big One" in northern Utah. We live on/near a fault line that rarely produces earthquakes. A 5.4 with a ton of aftershocks happened, so some awareness has been raised, but there's countless buildings/structures in Salt Lake County alone that will collapse in an earthquake.