Wednesday, May 18, 2016

The Wind at Our Backs

You can't do science with politics. Razors cannot slice glue. Science is a razor. Politics is glue. Everything, no matter how sharp, gets stuck in it.

The "climate change debate" illustrates the problem. There's really no debate about what we need to do. We got past that last December in Paris where it was agreed, much belatedly, that our "never exceed" temperature limit had to be 1.5C. That's 1.5 degrees Celsius above pre-industrial levels. Anything beyond that invites, perhaps even ensures, climatic calamity. 

1.5C it is then.

Everyone came away from Paris patting themselves on the back. Not sure why. What they left in Paris were national commitments, promises, by each nation of the cuts in greenhouse gas emissions it was willing to implement by specified dates. Such and such a percent by such and such year.

Unfortunately, when you add up all those promised cuts what you're left with is 3.5 degrees Celsius of warming and not to put too fine a point on it but that's not survivable for most life on Earth, including you and me and our kids and theirs.

The problem with a political approach to climate change is that it gets bogged down with man-made (anthropogenic) global warming. It's as though we're the only players at the table. That 1.5C is for us. We don't have to share it. That ignores who else is sitting at the table - nature.

Nature, represented by physics, geology, chemistry, hydrology, biology, zoology, botany, meteorology, glaciology, atmospherics, and every other Earth science, also has a handful of cards and that hand is also in play.

We don't know how Nature will play its hand. We do know that it's upping the ante.

That 1.5C goal reached at Paris? There's a hitch. We're already there. We've already loaded the atmosphere with enough man-made greenhouse gas that we've locked in 1.5C of overall warming. Every fossil-fuel generating station, every wildfire, every tank of SUV juice, every truckload of cement - that's all atop the existing 1.5C loading. Congratulations. We've set ourselves an ambitious target we have already exceeded. 

Don't worry, we're working on a plan and it's going to be a dandy. We'll have carbon taxes even as we ramp up the extraction and export of bitumen to world markets. Oh yeah, and we're still selling coal to boot.

But what about Nature? Well, what about it? The 1.5C target? That's all about preventing catastrophic, runaway climate change. What does "runaway climate change" mean? It means Nature, natural processes that we cannot control that will overheat the Earth. Science tells us these natural impacts can eclipse anything man-made.

Well, we're at 1.5C or we soon will be so what then? The mechanism of runaway global warming is thought to involve triggers known as "tipping points" that, when reached, will activate "natural feedback loops" that are unstoppable. Our best guess is that those tipping points will be passed at 1.5C of man-made global warming or at least that's the political narrative.

When this whole scenario was first floated (not all that long ago) it imagined the Arctic being ice free - by about the year 2100. No one imagined it could happen by 2016, more than 80-years sooner than anticipated. Oopsie!

So, what happened? Natural feedback loops, that's what happened. The Arctic warmed, sea ice thinned and then disappeared. In place of that white, reflective ice cover that once bounced solar radiation safely back into space, dark green ocean water began absorbing that solar energy, heat. The Arctic Ocean got warmer and it warmed the atmosphere above it and that set a whole bunch of wheels in motion.

There are knock-on effects, one feedback loop triggering others. As the Arctic warmed, boulders of frozen methane, "clathrates" a.k.a. "fire ice," lining the ocean floor and many lakes began thawing, releasing plumes of methane gas to the surface and upwards into the atmosphere. Methane is a more powerful greenhouse gas than CO2. It's not as long-lasting as carbon dioxide but it's persistent enough (about 12-years) to do a lot of damage.

Much of the terrestrial Arctic is comprised either of exposed rock or tundra, which is basically ancient peat. Peat, of course, is rich in hydrocarbons and makes a dandy fuel, ask any Irishman. Until now most of the CO2 held in the tundra has been safely sequestered by cold temperatures. However the warmer Arctic temperatures have been causing the tundra to dry out which transforms it into dandy fuel for wildfires. As you might imagine, we don't have much firefighting capacity in the Arctic, no way to extinguish tundra fires.

A tundra fire has three knock-on effects. The combustion releases CO2 to the atmosphere. The fires also produce "black soot" that is blanketing the surface, absorbing heat to speed up the melting of snow and ice. This is a big problem for the Greenland ice sheet, accelerating the melting which contributes to sea level rise around the planet. The third, knock-on effect is that, as the tundra burns, it exposes the layer beneath it, the permafrost. That is a huge methane trap. As it becomes the perma-no-more-frost, as it thaws, that methane is also released to the atmosphere.

So there you have a neat little bag of feedback loops. If you reverse engineer it, the existence of feedback loops evidences tipping points that were passed some time ago. There may be other, perhaps slower onset feedback loops that haven't come to our attention yet.

Two that are in evidence are the retreat of glaciers and the broken hydrological cycle. We have warmed the atmosphere. 15 of the 16 hottest years on record have occurred during this century. Heat melts glaciers. It also causes physical changes in the atmosphere. 

A warmer atmosphere is capable of holding more water vapour, a lot more as it turns out. That disrupts the hydrological cycle. Surface water is released to the atmosphere as water vapour through evaporation, perspiration and respiration by animals, and by plants through transpiration. It goes up into the air, condenses into clouds and then into rain and falls back to the surface where, among other things, it gives agriculture the water needed to grow our crops.

Once you have a warmer, wetter atmosphere it changes things. More water retained in the atmosphere means less water on the surface. This new reality contributes to precipitation changes. A warmer, wetter atmosphere is a more powerful atmosphere capable of triggering severe storm events of increasing frequency, intensity and duration. Bummer. Gives new meaning to "it never rains but it pours." Some places get sustained and severe drought. Other places get increasing precipitation, sometimes floods (thinking of you, Calgary). Some places get cyclical droughts and floods which, due to the soil compacting of drought can lead to destructive flash flooding. Double bummer.

Today's broken hydrological cycle can play utter hell on one of our most important carbon sinks, our forests. Trees absorb a lot of CO2 as they grow. Even when they die they can rot and create humus for the soil, another form of captured carbon that nurtures microbial growth - the "circle of life" thing. What keeps that all going is rain, precipitation.

Drought causes trees to dry out, even die off, which transforms the forest from immensely valuable carbon sink into disastrous carbon bomb. As the forest dries out it becomes fuel for wildfires (thinking of you, Fort Mac). These fires are also increasing in frequency, intensity and duration beyond our ability to control them. We're now dependent on rain to put them out. What a terrific time to have a broken hydrological cycle, eh?

Oh yeah, one more thing. Water vapour, of which we now have ever more in the atmosphere, thanks to anthropogenic global warming, is one of the most powerful greenhouse gases. There's more of it up there and it's accelerating the power of the atmosphere to trap solar radiation, blocking its escape back into space.

So, we've got these powerful feedback loops already in play (in an early-onset way) but the political narrative ignores them entirely. No, the political narrative focuses on how we cut, no "reduce," greenhouse gas emissions to stay within a target that we have already exceeded in order to avoid tipping points that we've already tipped that could trigger natural feedback loops that are already looping. Hmm, what's with that?

Well then what's the point of this political exercise after all if it's only Kabuki theatre? Ask yourself this. How would the public react if the government said, "Oh, to hell with it. What's the point?" Yet isn't that what they're actually saying through their actions?


Anonymous said...

We can change for the better.


The Mound of Sound said...

Yes, we can change for the better but have we reached the point where it's too little, too late? We're still working from a political number that ignores what nature is already visiting upon us. Nature is already in play. The whole idea of first 2C and then 1.5C was to prevent that.

Anonymous said...

Try as I might, Mound, I don't see the political will anywhere to make changes in time to avoid climate catastrophe. I certainly don't see it in Canada, where Trudeau seems content to carry on where his predecessor left off. Trudeau and the premiers are still talking about pipelines and LNG terminals. The NEB is still a victim of regulatory capture and the state security apparatus continues to brief tar sands operators and notorious pipeline polluters instead of shutting them down as a menace to national and global security.

I sadly don't share Trailblazer's optimism.


Troy Thomas said...

It's not that we'll change for the better. More likely, we'll be changed by what we can't even imagine.
There are abandoned cities across the globe with people that had to face a stark choice. Ditch civilization, and perhaps survive, or perish in the face of disaster. There are cities buried under earth, and submerged under water all over the world. Did the lost Mayans or the nearly forgotten Sumerians change for the better in the face of prolonged drought? Who knows?

The Mound of Sound said...

@ Cap - I think what you describe, this general failure of political will, is what I find most infuriating about this new Liberal government. I expected nothing better from Harper but I so hoped that a Liberal or NDP successor would reverse course and act decisively. Trudeau has wasted no time showing us his true colours and they're not what we were given to expect during his successful election campaign.

The Mound of Sound said...

@ Troy. It's been several years since I got my copy of Jared Diamond's "Collapse" the follow on book to "Guns, Germs & Steel." I suppose this is an appropriate time to go through it again.

History offers many examples of civilizational collapse from which some common traits emerge. Societies tend to collapse at their zenith and collapse comes on very quickly. There's no gradual decline.

Today we have a global civilization that is incredibly interwoven, inter-dependent. Past collapses were regional or even local. These earlier civilizations were also far more agrarian than what we have today. While organizationally a civilization might collapse, individuals were more self-reliant and capable of successful migration. How many of us today would have the faintest idea of providing our own food? Damn few. How many know how to hunt, how to fish, how to plant, tend and harvest crops? Not very many.

James Lovelock was interviewed a few years back. He predicted that humanity will emerge from this century with a global population well below one billion. Given that we're at 7+ billion now and purportedly heading to 9, that would be an apocalyptic die off.

At my age it enrages me that there's nothing I can do to protect my children from this.

Toby said...

James Lovelock, the Prophet

The Mound of Sound said...

Yes, Toby. I was floored to realize that "Revenge of Gaia" was published in 2006, a full decade ago. I still have it on my bookshelf. It's one of many books I must get around to reading again.

" 2004, Lovelock's friend Richard Betts, a researcher at the Hadley Centre for Climate Change-England's top climate institute – invited him to stop by and talk with the scientists there. Lovelock went from meeting to meeting, hearing the latest data about melting ice at the poles, shrinking rain forests, the carbon cycle in the oceans. "It was terrifying," he recalls. "We were shown five separate scenes of positive feedback in regional climates – polar, glacial, boreal forest, tropical forest and oceans – but no one seemed to be working on whole-planet consequences." Equally chilling, he says, was the tone in which the scientists talked about the changes they were witnessing, "as if they were discussing some distant planet or a model universe, instead of the place where we all live."

"As Lovelock was driving home that evening, it hit him. The resiliency of the system was gone. The forgiveness had been used up. "The whole system," he decided, "is in failure mode." A few weeks later, he began work on his latest and gloomiest book, The Revenge of Gaia, which was published in the U.S. in 2006."

Thanks for posting the link.