Get Ready for Drought. And Toxic Algae. Oh, and Exploding Permafrost

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Permafrost thaw on Herschel Island
Permafrost thaw on Herschel IslandCredit: European Space Agency/Copernicus Sentinel data 2018
Ruth Schuster
Ruth Schuster

We continue to fly, take cruises, drive for fun, and eat meat, et cetera. All these things indubitably drive climate change. We might forgo all these luxuries for the sake of the kiddies if not for our failure of imagination. We cannot imagine what a hotter world with higher sea levels will be like.

The sea has been the same level since the dawn of civilization following the last ice age; we know temperature fluctuations but cannot imagine unsurvivable heat and cold (for the obvious reason that we never personally experienced that either).

On Thursday, two unrelated papers were published in Nature and one in Geosciences that may help us imagine what we face. One is about algae. One is about drought. And one is about exploding permafrost.

To be clear, we don't know how bad things will get on Earth as we barrel ahead along the worst-case trajectory, which we are. We are in uncharted territory. But here are some examples of how bad things are already getting.

Don't ask, don't tell about that algal bloom

One paper in Nature addresses algal blooms in the U.S., and they don't even mean coastal blooms that are wreaking havoc such as the attack of deadly "sea snot" on Turkey that the Atlantic coined "a slimy calamity". This paper is confined to freshwater blooms which may affect everyone who drinks the water.

By and large plants adore climate change (so far); many like heat and happily breathe in the carbon dioxide. At a certain temperature, life will become uncomfortable, but the mean increase of about 1.2 degrees Celsius recorded so far has done nothing but good for algal blooms.

Glowing algal bloom flowing in China, 2018Credit: Zou Shan/AFP

Obligingly, the paper breaks down "nuisance harmful algal blooms" (NABs) and "toxic harmful algal blooms" (TABs) – there is no such thing as a "fortuitous algal bloom".

What is an algal bloom anyway? A sudden explosion in the population of algae (or blue-green bacteria) in fresh or seawater. Here we refer to the bad kind:  technically a kelp forest is an algal bloom, but kelp is good. Algal blooms are a natural phenomenon, but we have been massively feeding them by pouring sewage, agriculture runoff and other sun-dried crap into our waterways and seas, thereby poisoning our petri dish.

The paper's bottom line is that American water managers are being pig-headed and evincing reluctance to reach out and touch somebody else's knowledge about how to deal with this. To generalize, newbies apparently get taken aback when encountering blooms – inexperienced water managers pooh-pooh the problem until they actually encounter (and smell) it. But then, having dealt with it beforehand, they "become increasingly reliant on internal resources to respond to TABs once they occur rather than reaching out for external sources of information and technology."

Bloom of cyanobacteria in a freshwater pond in GermanyCredit: Christian Fischer

So, could it be that your water supply is poisoned by plants and may make one sick, and meanwhile your water manager is busy flexing his ego? In recent years, the authors write, whole cities have had to shut down their water supply for days – including Toledo after part of Lake Erie turned foul, and Salem, Oregon; "and there is little evidence that water systems are prepared for future events."

Nuisance blooms are no walk in the park. They stink, and the water tastes foul. Toxic blooms are worse: they kill the local marine life and can make people sick.

The lesson? Sharing is good in the case of brownies, a tasty Brie, and information about how to beat toxic algal blooms. Some archaeologists believe speech arose well over a million years ago as ancient hominins taught tool-making technology to the next generation. Other papers postulate Neanderthal speech. That may or may not be true but for sure, water managers can speak, and they should listen too; treating algal blooms is an infant technology still in development. They need help.

Drought: Oh the irony

A separate paper, published in Nature Ecology and Evolution,  explains that vegetation is presently enjoying climate change but actually, that excess plant growth may make droughts in certain areas even worse.

The problem is in areas where climate conditions spur plants to grow madly and pass the ecosystem's carrying capacity. That is technically called "structural overshoot" and renders the ecosystem more vulnerable to climate stress. This could even kill off forests.

The authors did the math and estimate that structural overshoot already contributed to around 11% of drought events from 1981 to 2015. Worse, this overshoot is often associated with compounded extreme drought and heat, which means the plants die faster and the drought's impact is worse than it would be if it were not preceded by overshoot.

So, they posit – because climate change is boosting vegetation, that could actually lead to frequent and stronger overshoot droughts.

On the somewhat-upside, overshoot droughts tend to be "flash droughts", shorter than regular ones by an average of 1 to 2 months.

Note that none of this will amount to a hill of parched beans if the forecast that the Middle East will descend to permanent mega-drought comes true.  

When your permafrost explodes

Permafrost isn't supposed to spontaneously explode. It's supposed to do nothing but sit there and not thaw. The whole idea of permafrost is that it never thaws – technically, it shouldn't thaw for at least two consecutive years, but in practice we expect it not to thaw beyond about a meter from the land surface in the height of summer. It also exists on the seafloor in the appropriate places.

Before climate change, about 15% of the Northern Hemisphere was underlain by permafrost, on which the nations of the north built their infrastructure and homes. These structures are now, in some areas, sinking, cracking and breaking apart where the accelerated global warming in parts of the north is degrading the permafrost, causing the landscape to change.

Sinkhole in SiberiaCredit: Rena094

In some cases, however, the permafrost explodes.  In western Siberia, at least since 2014, melting permafrost has been causing the ground to suddenly blow up, a team reported in Geosciences  earlier in September. They suggest a model for the specific conditions that enable this to occur, which we can largely ignore for the purposes of this article except to note that one condition is that the permafrost be gas-saturated.

And thus Siberia is home to date to around 20 gas-blast craters and more are anticipated. The first to be discovered was a huge 40 meters in diameter and 50 meters deep. When serendipitously noticed in the Yamal Peninsula in the summer of 2014, the internet was charmed – why yes, aliens were mentioned – but geologists were appalled. Two more were spotted in just the last few weeks, one just three kilometers from a major gas pipeline and the other near a railway.

Thawing permafrost in Alaska distorts a roadCredit: Dr. John Cloud/NOAA Central Libr

The Geosciences paper casts the blame squarely on climate change which degrades the permafrost. The latter, as it melts, is also likely to release more than long-dead naturally mummified megafauna: biologists dread the reintroduction of long-gone diseases to which we have no immunity

If that's your stamping ground, can an exploding sinkhole be predicted? Well, the data so far suggests that explosive gas emission is preceded by the development of a mound, which the Russians call bulgunnyakhs, the scientists helpfully observe. The mound is caused not by "frost heave" but by underground pressure building up, but beyond this tip, as the scientists observe – we just don’t know enough to build a model for mapping potential danger zones.

Oh, and by the way, methane is an extremely potent greenhouse gas; the more escapes, the faster global warming is expected to accelerate, melting the permafrost even more. Have we already reached a tipping point vis-à-vis methane escape from permafrost? We don't know but some think we have.

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