FOR THOSE WHO PREFER A WRITTEN EXPLANATION:
Alders Stone also offers some solutions in his article 'Why large-scale, abrupt climate change (probably) cannot be stopped (and we must, thus, increase our adaptability)' - which I have not included because I have not come across his name before and he does not claim to be a climate scientist [these can be found within the essay] however, I have included his description of how abrupt climate change works, because it seems very close to Professor Wadhams' description given within his lecture - although far more pessimistic.
If anyone knows that AH's explanation is fundamentally flawed - I would be grateful if they would leave a comment.
"The complexity and geophysiology are crucial elements necessary for understanding the current abrupt climate change event — likely the largest in 55 million years, with the real potential to destroy civilization as we’ve known if for a few centuries. Without knowledge of basic principles of complexity sciences and geophysiology, abrupt climate change cannot be fully and easily understood! The most important principles of complexity that must be understood are linkages (coupling between parts of the system); feedback, both negative (stabilizing) and positive (accelerating); the phenomenon of non-linearity(which is not trivial, but is understandable!); phase transitions to new attractor states at critical thresholds or tipping points. All of these (and more) are thoroughly and clearly explained in my Complexity 101 introductory seminar, now prerequisite to Climate 101.
But even more importantly — they are crucial concepts needed to effectively address this planetary crisis, to develop new cultural maps for the future to ensure our survival.
To reiterate and clarify, if we are to survive as a species, let alone achieve some form of sustainable existence with Ge for the long term — albeit at drastically lower number of humans on Earth — we must replace the obsolete and dangerous worldviews and cultural maps of the last 300 years — based in mechanistic sciences, AKA the Newtonian-Cartisian paradigm — with new ones based in complexity and geophysiology. For a great explanation of this, read chapter 8 — the most important chapter that most reviewers fail to grasp! – of Dianne Dumanoski’s The End of the Long Summer: Why We Must Remake Civilization to Survive on a Volatile Earth, one of the texts for Ermah Ge‘s Adaptability 101 program, 5th course in our Earth 101 series.
For now, the nut of my argument involves these elements.
CO2 and methane levels are at levels unprecedented in not only human history, but the last 2 – 3 million years at least. Average concentrations of CO2 during ice ages — the main state of Earth’s climate for 3 million years — is 180 ppm (parts per million). Average concentrations during interglacials — the warm periods between ice ages, like the last 10,000 years — is 280 ppm. Highest previously in the last 3 million years: 300 ppm. It’s now above 400 ppm, and accelerating — that is, the rate of increase — currently about 2 ppm/year — is increasing.
* Unlike water vapor and methane, CO2 has a LONG residence time in the atmosphere. Water vapor comes out and goes up daily. Methane has a half-life of approximately 9 years. But CO2 residence time — the technical term used to name how long it stays in the atmosphere — is measured in centuries. Even if we stopped burning all fossil fuels this year, the large percentage of the excess up there now will remain there for at least a century, and concentrations will remain high for up to 800 years.Why? CO2 does not condense like water vapor, and is not chemically removed like methane (oxidation). Instead, it must be ‘pumped down’ out of the atmosphere, which is a biological process that James Lovelock refers to as the CO2 bilge pump. The most important organisms in pump down are not trees — although they are important — but marine phytoplankton (algae) called coccolithophores — notably Emiliania huxleyi or Ehux — that produce calcium carbonate shells (mineralized CO2) that sinks to the bottom of the ocean to become limestone and chalk, thus removing CO2 from the system. This requires much time, and we are currently overwhelming the bilge pump. In addition, heating oceans and acidification are negatively affecting Ehux and relatives. This, in turn, is related to positive feedback #7 (see below).
* Natural positive (accelerating) feedback’s in Earth’s self-regulating metabolism and homeostasis — ERMAH — are accelerating heating, CO2 and methane levels. The three variables are linked in feedback relations. When any one increases, so do the other two, and it does not matter which increases first. In ice age to interglacial transitions, temperature increase first due to orbital variations (Milankovitch cycles), then CO2 and methane increase. In the current climate change, however, CO2 increased first due to human burning of fossil fuels. That in turn increase temperature, which is resulting in increase of methane from melting permafrost — 1/5 of Earth’s land surface — and melting methane hydrates (clathrates), water ice containing methane. Both are present in vast quantities in the Arctic.There are at least seven positive (accelerating) processes operating now. In the full essay, I will explain each. Here I’m simply listing them.
1] Melting permafrost increases methane in the atmosphere, which heats Earth, melting more permafrost, etc.
2] Heating oceans melts methane hydrates in coastal waters, which increases methane in the atmosphere, which heats the ocean, melting more hydrates, etc.
3] Forest fires worldwide are increasing, getting larger, more difficult to contain — firefighters claim that some are beyond current technology’s capacity to control. The main products of burning wood are water and CO2, which causes more heating, which causes heat waves and drought, increasing vulnerability of forests to pests and fires.
4] Soils are transitioning from net carbon sinks to net carbon sources. Microbial decomposition increases (up to a limit) as temperature increases.
5] Ice all over Earth is in decline. The most important currently Arctic sea ice, or ASI. Ice and the snow that accumulates on it is white, reflecting light, cooling the region (a negative, or stabilizing feedback involved in Ge’s temperature regulation). Ocean water is dark, absorbing light which is converted to heat, which heats the region. In addition, declining sea ice is allowing ocean currents from warmer parts of the ocean into the Arctic, melting ice from below.Because the Arctic is increasing 2X faster than any other part of Earth, unprecedented temperatures are rapidly melting sea ice. The majority of perennial ice — that which is years old — is now melted. What freezes back the following winter is 1-year old, thin and melts quickly the following summer, allowing more perennial ice to melt. Thus, the end of summer ice extent is declining rapidly. Nearly every year for the last several and the amount end of summer ice has declined. 2016 is expected to be a record year, beating the last record by a large margin.Some believe that we will see the Arctic ocean ice free by 2020 or sooner. When the Arctic ocean becomes ice free, all the heat will go into heating the water rather than melting the ice. The later absorbs MUCH more energy than the former. So heating in the Arctic ocean will accelerate when the ice is gone. Furthermore, once the ice is gone, it will not return for millennia or hundreds of millennia. Temperature will become too high.The heating Arctic is also disturbing the heat gradient between it and the equatorial region, which is heating more slowly. When the heat gradient is high — as in normal times — the polar jet stream demonstrates a strong, laminar flow west to east. When the gradient is low — as now — the polar jet meanders chaotically, allowing storm system, heat waves and droughts to become stuck for days, weeks or even months. This is having a major effect on weather worldwide.
6] Forest — especially coniferous forests (taiga) of spruce and fir — and other vegetation is moving north as the tundra melts. Those forests are dark — unlike the snow they replace. The tree shapes shed snow, exposing the dark even in colder seasons, further heating the region.
As oceans absorb more CO2, they are moving toward acidity. They are still alkaline (pH > 7) for now, but is less than the optimal pH for calcium carbonate formation and stability. This is affecting coccolithophores, corals, shell fish and other calcium carbonate producers that are the bilge pump.
Finally, for now, the topic of phase transitions to new attractor states at critical thresholds or tipping points. The main idea here is that systems at all scales — from chemical and cellular to organism and ecosystems to global climate systems — do not demonstrate just any kind of dynamics. They instead have a limited number of discrete — that is, clearly distinguishable from others — states called “attractor states”, because it’s as if systems are (metaphorically) attracted to one state or another. Furthermore, because systems show highly non-linear behavior, when some factor in a system — say, temperature — reaches a critical value, also called a critical threshold or tipping point, the system can rapidly shift to a new attractor state.
Earth currently — and for at least 3 million years — has at least three attractors: cold (ice ages), warm (interglacials) and hot (where we’re going next. Until the 1980′s, climatologists believed — based in evidence available at the time — that transition from ice ages to interglacials — that is, heating events — required hundreds if not thousands of years. However, beginning in the 1980′s and accelerating into the 1990′s and current time, ice core studies in Greenland and the Arctic has demonstrated something astounding: climate can lurch rapidly when a critical threshold is reached, such that such rapid transitions can occur in mere decades. In fact, even during ice ages, strong evidence points out that during ice ages, climate changes ten times more (e.g., heats up) in a single decade than we’ve seen in the last 8,000 years. In a single decade! (Study “Younger Dryas” event in Greenland for a fine,well-studied example.)
Let that sink in relative to the current heating event. (Heating is usually much faster than cooling, because the CO2 bilge pump is slow, even when is healthy, but now it is stressed and even slower.) That is, Earth climate could shift from the balmy interglacial state of the last few thousand years to a much hotter state — stabilizing at a state 5 – 8C ( 9 – 14F) above our current interglacial – in mere decades, and conceivably in a single decade. Such a transition will reek havoc on civilization, especially agricultural systems upon which billions of people rely for food, which in turn will cause socio-economic havoc (chaos), leading to increased conflicts. In such a scenario, that I expect will occur well before 2050, perhaps in my lifetime, large regions of Earth will become most uninhabitable by humans for most of the year (due to temperatures exceeding ‘wet bulb’ maximum, above which we can no longer cool via sweating. (Some technology, such as underground shelters, may help in such areas; but large-scale habitation of the last few centuries will be prohibited.)
From my perspective, given all the factors explained above — notably the long CO2 residence time and seven global scale positive feedback processes — I argue that the system has already crossed a tipping point for transition to such a hot state characterized as extreme, chaotic and violent weather, and that nothing we can do now — no level of mitigation to reduce greenhouse gas emissions even to zero — will stop it.
This does NOT mean we should not reduce emissions. Quite the contrary: we should, because failure to do so will not only speed the transition to a hotter, more chaotic, extreme and violent state, but we run the risk of transitioning to an even hotter attractor state beyond the next hot one. Doing so would have dire consequences for our species — and all others — potentially causing not only our extinction, but the end of most life on Earth. Temperature is a major factor determining stability of cell membranes, the weakest component of living systems, without which life as we know it cannot exist.
We would be wise to avoid such a phase transition."