Climate Change is Like an Asteroid Hit

Bumped, originally posted in August.

Here is another excerpt from my global warming science fiction novel “Great News”. It shows the use of the metaphor “asteroid hit” for climate change.

Update: An anonymous comment kindly points out that the asteroid hit would not result in “lava” blanketing the Earth, but “rock vapour at 6000 K”, which is worse, since it spreads much faster.

Actually, knowing that contributes to making the metaphor even better, since rock vapour would be a gas, just like CO2.


After I reach my office, I decide to spend some more time on climate activism. While I don’t participate in many demonstrations, I do contribute a bit of my time, as well as some of my money. Talking to Karen has given me an idea, and I want to write it down before I forget it.

The whole global warming crisis actually can’t be real. How can humanity possibly be simultaneously clever enough to develop modern civilization in the first place, and dumb enough to burn all the fossil fuel, permanently ruining the planet?

One possible explanation is that most people just don’t realize how horrible and catastrophic the “global warming” crisis will play out. They don’t understand the costs. So they think it’s no big deal using some more of the convenient fossil fuel.

“Global warming” doesn’t sound ever so threatening. “Warm” is actually a word that carries more positive than negative associations. People think of a nice warm day in spring.

My idea is to compare the crisis with the impact of a large asteroid. Everybody understands that would be very bad news for life on Earth.

I do some Internet research on asteroids and come up with a video simulation of a 500 kilometer diameter rock hitting Earth that the Japanese public owned television station NHK has posted on Youtube. It has over 1.2 million views. I like that number, since it tells me that there will be a lot of interest for the basic idea.

The asteroid hits the ocean, which makes sense. Most of the Earth’s surface is ocean area.

It causes a gigantic tsunami, which would be enough to flatten most coastal cities, but that would be the smaller problem. The bigger impact is from the lava that is ejected in enormous amounts into space, enough to cover the whole planet in an extremely hot blanket of liquid stone once it falls back. It takes less than a day for the lava to spread in a fierce firestorm all over Earth, turning the whole sky into fire everywhere.

All life on the surface of the planet will be burned to ashes within a day from the impact. Then all the ocean water will boil up into the atmosphere. The video shows the columns of the Greek Acropolis glowing from the extreme heat at the end.

I am quite convinced that life on the planet would be impossible after such an event.

And the only difference to global meltdown is that this happens much faster. With the asteroid, it only takes a day. But the end result is the same. If a runaway greenhouse effect leads to Venus syndrome, surface temperatures on Earth are going to go up by a couple of hundred degrees.

“Venus syndrome” is a theory developed by a famous NASA scientist who was one of the first to sound the alarm about global warming.

There is almost no atmosphere on the planet Mars, which means there is also no greenhouse effect on that planet. As a consequence, average temperatures there are around minus 50 degrees Celsius. In contrast, greenhouse gases in the Earth’s atmosphere heat the planet by about 33 degrees Celsius, giving us an average of 15 degrees Celsius surface temperature, which is just about ideal. The greenhouse effect on Venus is extremely strong, since it has an atmosphere, and that atmosphere is 97 percent CO2, leading to average surface temperatures of 450 degrees.

This fact about the atmosphere of Venus shows that there has been a runaway greenhouse effect in the history of that planet. The question is if the same thing can happen on Earth as well.

As it turns out, it very well can. The only question is what amount of CO2 in the atmosphere is necessary to trigger that.

Eventually, this will happen anyway. In about 1 billion years from now, the sun will have grown much bigger. That will lead to an increase of 10 percent of solar energy hitting Earth, which in turn will certainly trigger a runaway greenhouse effect, if there are no planetary engineering countermeasures in place.

Future generations will have to put up some serious shading technology. But another four billion years later, the sun will finally have expanded so far as to swallow Earth. If there are humans left then, they better develop some means of interstellar travel before that happens.

Can a runaway greenhouse effect also happen in the much nearer future as a consequence of human CO2 emissions?

There have been periods in the history of the Earth with several thousand parts per million of CO2 in the atmosphere. So even if humanity burns all the fossil fuel, the planet might still be safe.

However, when CO2 levels were at 2000 parts per million 250 million years ago, the solar energy hitting Earth was 2% less. That factor is equivalent to a doubling of CO2. So 2000 way back then is equivalent to 1000 now.

Also, there are actually no direct records of past CO2 concentrations. All there is are conclusions from other records. And some of the scientists now say that actually CO2 levels were not as high way back in history as assumed earlier.

And anyway, never in the history of the planet have CO2 levels gone up so fast. That is a factor that greatly increases the danger of runaway global warming. Burning all the conventional fossil fuels is an extremely dangerous experiment with the whole planet at stake. Burning the tar sands as well makes Venus syndrome a certainty, in the opinion of that NASA scientist.

So my idea for a climate campaign is comparing the potential damage from Venus syndrome to the damage from a 500 kilometer diameter asteroid impact. Again, the only difference is in the amount of time it takes to kill all life on the planet.

I don’t know yet how I am supposed to use this idea. I could of course write something about it, and spread that manuscript online. Or I could make a video with that basic idea. I am shooting videos all the time in my Paraponi Magic business, so I do have the equipment and the experience needed to produce something of halfway decent quality.

Then I can just post it on Youtube and get word out about it on my network of activists.

Anyway, I needed to write the idea down before I forget it, and I have done so now.

Published by kflenz

Professor at Aoyama Gakuin University, Tokyo. Author of Lenz Blog (since 2003,

2 thoughts on “Climate Change is Like an Asteroid Hit

  1. It is not lava that covers the Earth, it is rock vapour at 6000K, which is much worse than lava. Liquids cannot spread that fast and rock vapourises at 1700K. It is just an extremely large explosion and archea survived such impacts up to 6 times.


    1. Thanks, I was not aware of that particular detail, and am pleased to have learned something new today. I will update the post above accordingly, though I will leave the book unchanged for now.


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