Climatic Insouciance

Tuesday ~ December 13th, 2011 in Economics, Global Warming

In the wake of my initial posts on climate change Brad Johnson asked me to grapple with a number of different articles on the subject.

I think this is a conversation worth having but my core issue with the discussion’s current state is summed up in one of the pieces Brad points me to. Its entitled: Why two degrees really matters.

The problem is that it doesn’t actually tell us why 2 degrees matters. It tells us stuff like this

The warming-limit approach is analogous to how businesses conduct planning under uncertainty: Set a long-term goal, then work backward to determine how to achieve it, modifying plans dynamically as developments dictate. It’s operationally much more useful than a target for a single year. In fact, it can be used to derive such targets over many years, once the budget is allocated to developed and developing countries. It also has advantages over conventional, forward-looking policy analyses, which are hamstrung by the inherent limitations of economic forecasting models in accurately predicting the future.

Which is to say a lot of the discussion revolves around at what rate the planet is warming, what various emission targets would or could produce in terms of warming limits, etc. However, what I would love to get to center the conversation around is what we think is actually going to happen when the as the planet warms.

This is especially true, because I hear talk of apocalyptic scenarios bandied about. I am certainly not shy about apocalyptic thinking and analysis but to do it, we actually have describe the event chain that leads to the apocalypse.

If we can do that, we have something to work with.

Now, I am sure that someone, somewhere has done this. It would be helpful to get a pointer in that direction. As I said, I worked with the old Nordhaus models. I know those damage functions. I also know they are not really dynamic.

Nor, where they meant to be. These types of models were trying to bound prices on carbon. However, if we want to think about disaster, we have to talk about disaster.

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8 comments

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Tuesday ~ December 13th, 2011 at 6:14 pm

jpersonna

I imagine that if you modeled total impact to “environmental services” over the GW time frame, the impact of population growth would dwarf all else. Yes, biodiversity in remaining pristine areas might fall with GW, but pristine areas might be pretty well eradicated themselves.

I guess the last 100 years history of the oceans and their fisheries provide my model. I’m sure GW has had some impact, but so did the expanding human population’s demand for anything fishy.

Tuesday ~ December 13th, 2011 at 6:37 pm

My take has been that the disaster we will see is not Manhattan under water but farms in east Africa and south Asia becoming unproductive and the area residents being trapped by national borders or historic ethnic boundaries. Our military futurists name climate change as our military’s biggest challenge going forward. Not a good time to try to be the world’s policeman.

Tuesday ~ December 13th, 2011 at 7:13 pm

Curt Doolittle

I was deeply involved in the software for conducting inventories of gas emissions for a period of time, and have knowledge of the organizations that standardize the protocols.

There is a whole lot of planning going on out there in both industry and government. However, the global warming movement in general is somewhat in retreat. It will remain so for a few more years until the science has caught up with the ethics, and popular opinion is rescued from abuses of ethics, and a failure of making data transparent.

Tuesday ~ December 13th, 2011 at 7:19 pm

dcomerf

“we actually have describe the event chain that leads to the apocalypse” read p254 – 260 of James Hansens “Storms of my grandchildren”:

“As global warming continues, storm effects will ratchet upward in three major ways.
One of these ratchetings will be the development of more powerful and destructive midlatitude or frontal cyclones. Frontal storms will be more powerful, because they depend upon the temperature difference between the cold and warm air masses as well upon the amount of moisture in the atmosphere behind a warm front. This intensification of frontal cyclones will be an effect of melting ice sheets, once ice sheets begin to disintegrate rapidly enough to keep regional ocean surface temperature from rising as fast as continental temperatures and temperatures at lower latitudes. The most important point is that there will be places and occasions in which the warm air masses will be loaded with far more water vapour than would be the case in a cooler world. …
This first ratcheting, though, will pale in comparison to the effects of the second ratcheting: when ice sheets’ rapid disintegration causes a sea level rise measured in meters. …
Ice sheets eventually begin to disintegrate at rates of several meters of sea level per century, even with the slow pace at which natural climate forcings change. But predicting when ice sheet mass loss will accelerate in the twenty-first century is a notoriously difficult “nonlinear” problem.
We could “lock in” disastrous sea level rise very soon, that is, create conditions that guarantee its occurrence, but it is likely to be several decades before a rapid sea level rise begins. On the other hand, we have been surprised by how fast some other climate changes have occurred – such as disappearance of Arctic sea ice … For the moment, the best estimate I can make of when large sea level change will begin is during the lifetime of my grandchildren – or perhaps your children.
…
With the combination of a higher sea level, even of only a meter or so, and increased storm strength, the consequences of future storms will be horrendous to contemplate. … Social and economic devastation could be unprecedented. It is not necessary to put the entire island of Manhattan under water to make the city dysfunctional and, given prospects for continuing sea level rise, unsuitable for redevelopment. …
The timing of the third ratcheting effect of global warming, the melting of methane hydrates, is as unpredictable as the others. Warning signs are beginning to appear already, with bubbling of methane from melting tundra and from the sea floor on continental shelves. So far the amounts
of methane released in this way have been small. The methane hydrates of greatest concern are those in sediments on the ocean
floor, because of their great volume. …
The flooding of the ocean floor with warmer Pacific Ocean water may have been a key factor in the melting of methane hydrates during the PETM. Could a change of ocean circulation happen again
in the near future? Global models of today’s climate sometimes have a problem with spurious formation of deep water in the Pacific Ocean, which suggests that it would not take much change in the densities of ocean surface waters to alter the location of deep water formation.
The instigation for such a change could be freshwater additions to both the North Atlantic and Antarctic Oceans, after the rate of ice sheet disintegration in both hemispheres has reached high levels. …
When deep water formation begins in the Pacic Ocean, the inertia of the climate system, specically ocean circulation, will be far too great for humans to stop, even if social systems are still in order. Once large sea level rises begin to devastate coastal cities around the world, creating hundreds of millions of refugees, there may be a breakdown of global governance. But regardless of that, if ocean circulation changes, such that warmer Pacific Ocean water begins sinking to the ocean
floor and melting methane hydrates, there will be no plausible way for
humans to reverse that change of ocean circulation.
While we can’t predict the details of short-term human history, changes will be momentous. China, despite its growing economic power, will have great difficulties as hundreds of millions of Chinese are displaced by rising seas. With the submersion of Florida and coastal cities, the
United States may be equally stressed. Other nations will face greater or lesser impacts. Given global interdependencies, there may be a threat of collapse of economic and social systems.
Physical science is easier to foresee. While the timing of the three ratcheting effects is difficult to predict, their effects are not. With methane hydrate emissions added on top of those from
conventional and unconventional fossil fuels, the future is clear. Diminishing feedbacks that help to keep the magnitude of natural long-term climate changes within bounds, such as the
ability of the long-term carbon cycle to limit atmospheric carbon dioxide, will have no time to counter amplifying feedbacks. The huge planetary energy imbalance caused by the high levels of atmospheric carbon dioxide and methane will take care of any remaining ice in a hurry. The
planet will quickly get on the Venus Express. …
a devastated, sweltering Earth purged of life may read like far-fetched science fiction. Yet its central hypothesis is a tragic certainty – continued unfettered burning of all fossil fuels will cause the climate system to pass tipping points, such that we hand our children and grandchildren a
dynamic situation that is out of their control.”

Wednesday ~ December 14th, 2011 at 4:02 am

Ole Rogeberg (@freakynomics)

I don’t remember your initial post on this so I might be missing some context, but it sounds as though your question is “What specific consequences would a two degree increase in global mean temperature have?”

One attempt to answer this is in the journalist Mark Lynas’s book “Six degrees”, which has a chapter for each degree of warming that attempts to summarize the scientific literature he could find concerning consequences.

My copy is from 2008, it might have been revised since then. The summary notes I’ve put in front of the 2 degrees chapter (for what its worth):
*Reduced “depth” of monsoon (won’t reach as far into India)
*European droughts and deadly heatwaves
*Increased forest fire risks around Mediterranean
*MIgration northwards from southern europe
*Albedo flip and Greenland ice collapse
*Water problem, floods and migration/agriculture in India/Asia
*Glaciers in the Andes dry out, drought in cities
*Droughts in California etc. as snowpack reservoirs go
*Reductions in global food proudction
*Large scale species loss

The book itself – if I recall correctly – has more on why these things are supposed to follow, how speculative the different effects are, to what extent they are implications he himself draws from the research findings and to what extent they are claimed by the scientists etc.

Wednesday ~ December 14th, 2011 at 10:13 am

Corey Mutter