Weather bugs

I mentioned in an earlier post that I have a sneaking suspicion that we’re being crowdsourced by bacteria. Remember? The human body has 10 trillion cells in it. We also each harbor about 100 trillion microbes. There is more microbial DNA in the human body than human DNA. That post.

We know relatively little about this huge population, but one thing we do know is that it’s not random. I claimed, back in May 2011, that perhaps humans are not so much organisms as we are ecosystems.

We thought we were the top guns on this planet! We thought it was all about us! We thought our bodies were vehicles for our splendiferous brains! No, silly. We are being maintained. We exist simply as biomes for colonies of established bacteria. Our brains probably just evolved as the best way for our bacteria to ensure that they will continue to have thriving hosts, generation after generation.

You might have laughed that one off, and I can understand your reaction. It’s a little unsettling to think that humans aren’t the center of the universe. Galileo encountered a little resistance, too. I can be patient.

But why?  You might ask. Why would they want us to do their bidding? And what is their bidding?

Would it help you see my point of view if I told you that bacteria are controlling the weather, too?

But first, a little background on where clouds come from.

There are lots of aerosols floating around in the atmosphere – minuscule particles of pollution, soot, dust, minerals, and salt sprayed up by the oceans. And there are bacteria, too, whipped up in the winds that blow across the Sahara, riding on the backs of beetles and pollen grains, blown off of vegetation all over the world.

Water condenses onto these tiny particles and microbes in the atmosphere to form ice crystals and clouds.  Contrails that form behind airplanes are are just ice crystals that formed on the particulates that spewed out behind the jet engines.

But according to recent research, described in  this article that Dave pointed out to me (despite being p.o.’d that I had said he was only good for backups), the bacteria go one farther than the other aerosols. They influence the cloud physics.

In 2008, Brent Christner of Louisiana State University reported isolating ice-nucleating bacteria from rain and snow. A year later, another group found microbes associated with at least a third of the cloud ice crystals they sampled at an altitude of 8 kilometers. Pure water molecules won’t freeze in air at temperatures above about –40 degrees Celsius, Christner notes. Add tiny motes of mineral dust or clay, and water droplets may coalesce around them — or nucleate — at perhaps –15 degrees. But certain bacteria can catalyze ice nucleation at even –2 degrees.

(Emphasis mine). The bacteria change the chemistry of ice crystal formation, so that crystals can form at higher temperatures, and thus lower altitudes. Why does this matter?

In the summer of 2011, Bozeman Montana was pummeled with two massive hailstorms. I know this because I saw my brother’s pickup truck; it looked like someone had thrown golf balls at it from close range.

An enterprising Montana State researcher saw the hail and had a eureka moment. He tested the hail for bacteria. Apparently no one had thought of doing that before. Guess what he found in the core of these monster hailstones? Bingo. Bacteria. Lots of ’em – some 1,000 cells per milliliter of meltwater.

Now the thing about hail is that it usually only forms at about -15 degrees. The cloud has to be really high in order for that to happen. But with bacteria in it, the hail can form much lower in the cloud, and if the thunderstorm has really strong updrafts, I suppose that means that really monstrous hail can form.

So what’s in it for them? Why would bacteria bother getting involved? Here’s a 2008 National Geographic News article entitled “Rainmaking bacteria ride clouds to colonize Earth?” that summarized a scientific article claiming that bacteria may have evolved to influence the weather as a way to get around.

Rainmaking bacteria that live in clouds may have evolved the ability to spur showers as a way to disperse themselves worldwide. […] One possible explanation is that the bacteria rely on the atmosphere—and rainfall—to disperse, much like plants rely on windblown pollen grains to colonize new habitats. For instance, an organism specialized to live on plants may become airborne, spur ice formation in clouds, and then travel back to Earth with that precipitation.

The article went on to say that this symbiotic relationship between vegetation, bacteria and rain could possibly explain why overgrazing or deforestation could lead to droughts. So not only are they influencing weather, but bacteria could also be playing a role in climate change.

Another research team, this time just over the border in Clermont-Ferrand, France, recently found that bacteria in clouds are super-efficient at cranking CO2 out into the atmosphere. They sampled a cloud and found at least 17 different types of bacteria that can break down organic pollutants like formaldehyde, acetate and oxalate, releasing carbon dioxide as a by-product.

This microbial transformation of pollutants to carbon dioxide occurs even in darkness. Amato has calculated the total nighttime microbial production of carbon dioxide in clouds and pegs it “on the order of 1 million tons per year.” Though not a huge sum (equal to the carbon dioxide from perhaps 180,000 cars per year), he cautions that this amount could increase based on airborne pollutant levels, temperatures and microbial populations.”

I’m wondering how they can calculate the “total nighttime microbial production of CO2 in clouds.” Seems a bit of a stretch – we don’t even have any idea of the distribution of organic pollutants in the atmosphere, much less where big gangs of bacteria are hanging out. But in any case, it sounds like the more we pollute and the warmer it gets, the more CO2 they’ll generate. Not a great scenario.

This brings me to my obvious conclusion. Perhaps bacteria evolved to influence the weather because their ultimate, collective goal is to alter the global climate. Could global warming in fact be a massive bacterial plot? My guess is that they’d like Earth to be a few degrees warmer than it is now.  The “success” of humans in mastering the planet starts to look a little different now, doesn’t it? Perhaps in reality we’ve been massively crowdsourced just to speed up global warming. And when it’s nice and warm? Well, they won’t need us any more then, will they?

Ever since that damned asteroid hit we’ve been trying to get this planet warmed back up. It’s just too cold for comfort around here.

And here we’ve been blaming the whole thing on ourselves.

Illustration: Dan Smith

2 thoughts on “Weather bugs

  1. Interesting. Thanks Mary. There was an article in the 25 February edition New Scientist – ‘The Wonders of the Sky’ – which had a section on the phenomenon of high-flying bacteria and fungi, sometimes affecting our weather. The article states “… signs are that some life survives at altitudes of more than 60km.”

    We humans flatter ourselves by thinking we are the most significant creatures on the planet. We’re not. Try as we might – with pollution, climate change, environmental destruction, etc. – we’ll never render Earth uninhabitable. Uninhabitable for us, yes. But the microbes will survive to start the whole process all over again.

    • Hi Alistair,

      Yes, I think we are limited by our brains, even as we think that our brains are what make us so superior. Collective intelligence is something we have a hard time understanding, much less appreciating. The planet will go on long after we’ve made ourselves obsolete. Of that, I’m certain. I find it all really fascinating. Thanks for commenting!

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