Friday, March 9, 2018

Climate Tipping Points

Like many college students, there has been a sense when the subject was climate change that we could always "cram for the final" when things got really serious. Now I feel a shift in tone—there is a sense of urgency. Below are two short pieces that address why this may be so. The first addresses the new and truly frightening data the great scientific measurements can provide. While second talks about the disappearing paradise that was Santa Barbara California. Two different looks at impending doom and how close it may be.

The Current Onset of Climate Tipping Points


As extreme temperatures, the rate of sea ice melt, the collapse of Greenland glaciers, the thawing of Siberian and Canadian permafrost and increased evaporation in the Arctic drive cold snow storms into Europe and North America, and as hurricanes and wild fires affect tropical and semi-tropical parts of the globe, it is becoming clear Earth is entering a shift in state of the atmosphere-ocean system associated with destructive climate tipping points. As Arctic permafrost is thawing an analogy with geological methane-release events such as the 56 million years-old Paleocene-Eocene boundary thermal maximum (PETM) event is becoming more likely.

As is well known to students of the history of the climate, once a temperature threshold is breached, abrupt weather events ensue amplified by feedbacks such as decreased reflectivity of the Earth surface and enhanced release of greenhouse gases, often within short time frames.

Figure 1. 1880-2018 annual mean temperatures and 5-years smoothing.

Such abrupt changes are occurring at present. As mean global temperature has exceeded 1.2 degrees Celsius above 1880 temperatures (Figure 1), sharp reductions occur in Arctic sea ice from 45 percent in 1985 to 21 percent in 2017[i], when the ice cover was 8.5 percent lower than the average of 1981-2010[ii].

As the ice melts the near-total reflection (high albedo) of solar radiation from the ice is replaced by absorption of infrared radiation by open water; The flow of ice-melt water from the Greenland glaciers creates a large pool of cold water in the North Atlantic Ocean. The cold water region south of Greenland slows-down to aborts northward flow of the thermohaline Atlantic Meridional Ocean Circulation (AMOC), leading to cooling of the North Atlantic and adjacent North America and Europe[iii].

Rising temperature and evaporation over the warming Arctic Ocean results in build-up of masses of cold vapor-laden air, intermittently penetrating into lower latitudes through the weakened undulating boundary of the high-altitude polar vortex, which allows penetration of snow storms southward through Siberia and North America[iv](Figure 2).

Figure 2. Arctic air temperatures in January 2018 in degrees Celsius relative to the average (Arctic sea – 3-9 degrees, yellow to red; Greenland and Siberia (-1 to -3 degrees C, blue to magenta) Credit: NSIDC courtesy NOAA/ESRL Physical Sciences Division.

In 2006 the Greenland and Antarctic ice sheets experienced a combined mass loss of 475±158 Gt/yr (billion ton/year), equivalent to 1.3±0.4 mm/year sea level rise. The acceleration in ice sheet loss over the last 18 years was 21.9±1 Gt/year2 for Greenland and 14.5 ± 2 Gt/year2.

The slow-down to collapse of the northward flow of warm water from tropical regions, namely the Atlantic Meridional Ocean Circulation (AMOC), originating from the Gulf of Mexico, and further warming of the tropical ocean pools, produce in temperature polarities with cool northern ocean regions. This ensues in storms and hurricanes in regions such as the Caribbean islands. Warming of the west Pacific Ocean leads to cyclones such as have affected the Philippines, Fiji and Samoa,

Polar warming is leading to the release of large amounts of methane from frozen organic matter stored in the permafrost and from methane hydrates in lakes, the sea and sediments. This has already raised atmospheric methane levels during 1960-2017 from ~1600 parts per billion to 1860 ppb. The bubbling of methane is locally leading to collapse and cratering of the permafrost. The total mass of methane on land of ~2050 GtC (billion tons) and methane hydrates at sea of ~16,000 GtC (Global Carbon Project) is some 30 times greater than the >600 GtC which has been produced by anthropogenic emissions since the onset of the industrial age. Even a release of 10 percent of Arctic-stored carbon would raise atmospheric greenhouse levels by a factor of about three.

The current warming of Earth manifest in the Arctic Sea, the melting of polar ice sheets, penetration of snow storms into mid-latitudes, permafrost thaw, hurricanes and wildfires and the rise in extreme weather events, manifesting a shift in state of the atmosphere-ocean system, constitutes an existential threat to humanity and much of nature.

Apart from sharp reduction in carbon emissions, there appears to be one chance to save the biosphere as we know it, namely CO2 down-draw using every available method (cf. basalt dust application of soils, carbon cultivation of soils (biochar), CO2 removal by air streaming through basalt, extensive sea weed farms, ‘sodium trees’ sequestering CO2 using sodium hydroxide in pipe systems). This would require funds on the $trillions-scale currently allocated for the military and for wars, humanity’s choice being between ongoing wars and defense of the Planet.







Southern Californians know: climate change is real, it is deadly and it is here

An earthly paradise is ravaged by inferno and flood, the earth itself rising to proclaim a horrifying and deadly new normal
Nora Gallagher, 3 Mar 2018

When people ask me where I live and I say, “Santa Barbara,” I wait for the inevitable reply, “Paradise,” and the quizzical look that says, how does one live there, rather than vacation. It’s as if I had replied, Disneyland.

People who visit from colder climates have been complaining lately. Last year, when it finally rained after six years of drought, and we were practically on our knees with gratitude, a woman from New England remarked, “I didn’t come here for the rain.” I almost said, “Well, then, why don’t you go back home?” Another pestered a friend: when was her club in Montecito going to open? My friend replied, “I think it’s under eight feet of mud.” She wanted to add, “And they’re still looking for the bodies.”

It’s always been a struggle here to have a normal life, to hold on to reality.

In December, we got a mega-dose of reality when the biggest fire in California’s history burned more than 270,000 acres. Seven cities were evacuated.

When the air was labeled “hazardous” for three days running, we made plans to leave. On Sunday morning, my phone pinged a mandatory evacuation for Montecito. I called a friend who lives there. “Packing,” she said. The fire was less than a mile away. I drove through the brown air and falling ash to a gas station and when I got there, my credit card wouldn’t work; the power was out. I stood in the zombie snow as others lined up behind me. Finally, we drove north to a hotel on the coast, where, with evacuated friends, we hiked and walked together along the shore.

After we’d been there a few days, I woke up at 3am and thought of a movie I’d watched years ago. Ava Gardener and Gregory Peck waiting for the fallout from a nuclear war in the northern hemisphere to float on the wind to them in Australia. They were going to die, and everyone and everything they cared about was already dead or was going to be. I remembered a lot of drinking and dancing, fruitless searching by submarine along the coasts of the United States for survivors and Fred Astaire fixing up his sports car so he could rev it up in his garage and commit suicide.

I thought, we are On the Beach.

Like them, we were hardly refugees. We hadn’t walked out of our houses not knowing where we were going or who would take us in. But still, hanging over our hikes, was dread.

And what was coming toward us? Immediately, it was the fire. The fire at that point was burning so hot it was basically gas. Because of the long drought, the lack of rain this season, and Santa Ana winds in December.

But we were waiting for something else, too.

And then, the firefighters, all 8,549 of them, stopped the fire and we went home for Christmas.

In early January, a tropical storm from the south hit the newly burned mountains above Montecito between two and three in the morning, and dropped a half-inch of rain in five minutes. A force of water and ash and soil no longer secured by plants picked up boulders on its way down the mountain and swept into the town. My friends in Montecito were just too tired to evacuate ahead of this storm. A firefighter told them the day before. “If you hear a sound like a freight train, get up on the second story or the roof.” They woke up at three under a red sky from houses exploding over severed gas lines and they heard it: “A terrible grinding roar.” It buried houses and cars and people. It buried the freeway and the train tracks. All the way to the ocean. A body of a man was found on the beach. Not far from him was the body of a bear.

Broken houses line mud-caked streets, and two people are still missing including a two-year-old. We are no longer a pretty backdrop, and our hearts aren’t pretty, either.

And we know now what the dread was we felt in December. Call it climate change or climate collapse, that was the Big Dread behind the smaller ones. Climate believers, climate deniers, deep in our hearts we think it will happen somewhere else. Or, in some other time, in 2025 or 2040 or next year. But we are here to tell you, in this postcard from the former paradise, that it won’t happen next year, or somewhere else. It will happen right where you live and it could happen today. No one will be spared.

So, if you are driving around and flying on airplanes and ordering things to be shipped by truck and making money off oil stock the way so many of us are – like there’s no tomorrow? We are here to tell you there is a tomorrow and we are living in it.

If you visit, talk to us as if our dose of mega-reality is not some singular string of bad luck or an inconvenience to you. Help tether us to the reality we are – all of us – living in now and that we in southern California don’t want to forget in the face of returning to “normal”. Give us the one gift that will help us: please, let’s not go back to business as usual. more

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