The researchers had to suit up just to enter it.

Well this was really cool.

I'm taken back to the boat, I'm given a gas mask

He bleeds out pigs.

More recently, into the Black Sea, where we're exploring.

And here's the weapon, it seems, that it did so over the last 500 million years.

Six hours later, up goes the temperature.

We inject our own aerosols into the atmosphere, and we have trace gases, and not just carbon dioxide it's methane, ozone, oxides of sulfur and nitrogen.

And here's the really important point.

You're in an accident.

But there's a far worse danger confronting us.

What about the... the phosphate gas?

And with money we got from DARPA, we could show just that.

And so we thought, like in a game of musical chairs, might we be able to give a person some hydrogen sulfide, and might it be able to occupy that place

So there's a bunch of hydrogen molecules around, and some of these iodine gas molecules around.

They stop complex life from existing.

One thing those people did out there was take this technology of hydrogen sulfide, which is this start up company that's burning venture capital very quickly, and they fused it with another company that sells another toxic gas that's more toxic than hydrogen sulfide, and they give it to newborn babies who would otherwise die from a failure to be able to oxygenate their tissues properly.

At the end of the Permian, at many of these mass extinction boundaries, this is what we find isorenieratene.

If you look at carbon dioxide from burning tropical rainforest, or methane coming from cows and rice, or nitrous oxide from too many fertilizers, it turns out agriculture is 30 percent of the greenhouse gases going into the atmosphere from human activity.

We have to go in with protective suits and breathing gear, and 30 parts per million of H2S will kill you.

Peter Ward

Phosphine gas.

And so, we wanted to find out might we be able to use hydrogen sulfide in the presence of cold, and we wanted to see whether we could reproduce this skier in a mammal.

Where have essentially, you have an equal amount and very

But in the meantime, for the next decade at least, the name of the game is hydrocarbons.

And the worst effect of global warming, it turns out hydrogen sulfide being produced out of the oceans.

This is regularly several hundred parts per million.

You only have to go to the Black Sea and a few other places some lakes and get down, and you'll find that the water itself turns purple.

There is tremendous amounts of hydrogen sulfide coming into this cave from volcanic sources and from the breakdown of evaporite minerals below the carbonates in which this cave is formed and it is a completely hostile environment for us.

Phosphine gas. What about it?

And now you hit it with a little hydrogen gas.

And you hit it with some electricity and the HF will split into hydrogen gas and fluorine gas.

And what you're seeing here is a cloud of densely packed, hydrogen sulfide rich water coming out of a volcanic axis on the sea floor.

As you can probably tell from its name, carbohydrates contain carbon, hydrogen, and oxygen.

The clouds are mostly hydrocarbons.

It's filled with this toxic gas, hydrogen sulfide.

So, it was interesting for us when we applied hydrogen sulfide to a mouse when it was also cold because what happened is the core temperature of the mouse got cold.

And we think this is the reason that complexity took so long to take place on planet Earth.

So, these are the thought leaders in trauma medicine all over the world saying this is true, so it seems that exposure to hydrogen sulfide decreases damage that you receive from being exposed to otherwise lethal low oxygen.

And then above that, you're just adding more and more hydroxide.

Am I understanding you right, that what you're saying here is that we have in our own bodies a biochemical response to hydrogen sulfide that in your mind proves that there have been past mass extinctions due to climate change?

The mycelium is producing enzymes peroxidases that break carbon hydrogen bonds.

Each cylinder is about 10 percent ancient air, a pristine time capsule of greenhouse gases carbon dioxide, methane, nitrous oxide all unchanged from the day that snow formed and first fell.

Now, in a water cooled reactor, you have a system called a recombiner that will take the hydrogen gas and the oxygen gas that is always being created from the nuclear reaction and put them back together, because chemically they'd much rather be water than being hydrogen and oxygen.

And this company, the first thing it did was make a liquid formulation of hydrogen sulfide an injectable form that we could put in and send it out to physician scientists all over the world who work on models of critical care medicine, and the results are incredibly positive.