The Titanic moment--beyond the point of no return

‘Knowing how long societies have to react to pull the brake on the Earth’s climate and then how long it will take for the ship to slow down is the difference between a climate emergency and a manageable problem.’ Photograph: Topical Press Agency/Getty Images

A fascinating article from the Guardian.

Formula for climate emergency shows if ‘reaction time is longer than intervention time left’ then ‘we have lost control’

When is an emergency really an emergency?

If you’re the captain of the Titanic, approaching a giant iceberg with the potential to sink your ship becomes an emergency only when you realise you might not have enough time to steer a safe course.

And so it is, says Prof Hans Joachim Schellnhuber, when it comes to the climate emergency.

Knowing how long societies have to react to pull the brake on the Earth’s climate and then how long it will take for the ship to slow down is the difference between a climate emergency and a manageable problem.

Rather than being something abstract and open to interpretation, Schellnhuber says the climate emergency is something with clear and calculable risks that you could put into a formula. And so he wrote one:

Emergency = R × U 
R= p × D   
U = τ / T

Risk (R) = probability (p) ×  damage  (D)
Urgency (U) = reaction time (τ) /   time left to avoid a bad outcome  (T)

This is a fascinating way to look at it.  

Over the last 30 or 40 years, the perception of p and D has risen dramatically, while T has fallen sharply.  It seemed logical to many in 1970 to argue that the damage (D) from climate change would likely be low, and the thesis that CO2 would raise global temperatures, while interesting, was still untested.  It was also thought that we had lots of time (T) .  It seemed to politicians and the public that action wasn't urgent.  Now we know, as a fact, that global warming is happening, and that it's caused by rising levels of greenhouse gasses in the atmosphere, and they are caused by us.  And the negative consequences of global warming are happening faster than was thought even just 10 years ago.  R has risen sharply and so has U.  And τ looks as if it is longer than we might have thought.  Getting individual countries to act is taking too long.  Denialists, either funded by fossil fuel interests, or useful idiots, continue to lie about climate change. 

The article continues:

In a comment article in the journal Nature, Schellnhuber and colleagues explained that to understand the climate emergency we needed to quantify the relationship between risk (R) and urgency (U).

Borrowing from the insurance industry, the scientists define risk (R) as the probability of something happening (p) multiplied by damage (D).

For example, how likely is it that sea levels will rise by a metre and how much damage will that cause.

Urgency (U) is the time it takes you to react to an issue (τ) “divided by the intervention time left to avoid a bad outcome (T)”, they wrote.

Schellnhuber, of the Potsdam Institute for Climate Impact Research in Germany, tells Guardian Australia the work on the formula was just the “tip of a mathematical iceberg” in defining the climate emergency.

“It can be illustrated by the Titanic disaster, but it applies to many severe risks where you can calculate the do-nothing/business-as-usual probability of a highly damaging event,” he says. “Yet there are options to avoid the disaster.

“In other words, this a control problem.”

There is a time lag between the rapid cuts to greenhouse gases and the climate system reacting. Knowing if you have enough time tells you if you’re in an emergency or not.

Schellnhuber used “standard risk analysis and control theory” to come up with the formula, and he was already putting numbers to it.

“As a matter of fact, the intervention time left for limiting global warming to less than 2C is about 30 [years] at best. The reaction time – time needed for full global decarbonisation - is at least 20 [years].”

As the scientists write in Nature, if the “reaction time is longer than the intervention time left” then “we have lost control”.

Schellnhuber says: “Beyond that critical point, only some sort of adaptation option is left, such as moving the Titanic passengers into rescue boats (if available).”

[Read more here]

So let's see what kind of cuts to emissions are needed.  Instead of zero carbon by 2050, let's say we must cut emissions by 90%, to 10% of what they are today, though obviously we will go on cutting emissions after 2050.  It's just that we need to get there by 2050 or the rise in global temperatures will exceed 2 degrees C. The 10% left will be offset by tree-planting (or any other workable de-carbonisation method.)  To achieve a 90% cut in emissions, we need to cut them by a compound 7.4% per annum.  Which will be very hard to do, i.e., τ is greater than T.  Which means we have lost control.  It's an emergency.  A Titanic moment.  The iceberg is up ahead and cretins and fools are still lying about it.

What if we settle on an 80% cut by 2050?  That will require a compound rate of decline of 5% per annum.  We might be able to offset the remaining 20% by tree-planting.  Maybe.

So at a bare minimum, we must cut emissions by a cumulative compound 5% per annum, preferably more, to avoid an emergency.  How?

1. No more coal power stations must be built anywhere, ever.  That means we must lean on China, India, Pakistan, Bangladesh, South Africa and other laggards to stop building coal power stations now.  In the "West", coal power stations are being shuttered, because they're old and getting near the end of their lives, and new coal power stations are too costly compared to renewables and gas.  The exception is Australia, where a government of more than usual stupidity wants to build a new coal power station with a government subsidy.  Just because it'll irritate the "greenies" and "leftists".
2. The big falls in European electricity generated by coal have come about because of the European carbon price, which is (finally!) biting hard.  The moral of that story is that we need a carbon price everywhere, and countries which have one should levy taxes on imports from countries which do not.  I have no doubt that (a) a carbon price won't impact growth (see Sweden and British Columbia and Australia, when we had a carbon price) and (b) will cut emissions drastically.  It could start at $20 a tonne of CO2, rising  by $3/tonne each year thereafter. The small (in absolute) terms rise in the European carbon price has had a significant impact on coal usage.  The proceeds of a carbon tax could be distributed to the people as a monthly "carbon dividend".  This will reduce political opposition.
3. After electricity generation, vehicle emissions are the next largest, and will likely mean that this year's total global emissions won't fall, even though coal-sourced emissions will fall by 3%.  (In the USA, vehicle emissions now exceed emissions from the power sector.)  EVs should get a subsidy of $5-$10K per car when you buy a new one, falling by $1000 each year, because battery costs are plunging and subsidies won't be needed in 5 or 10 years' time.  And the carbon tax should apply to petrol (gasoline) and diesel, to make the incentive to switch even stronger.
4. We need an end to fossil fuel subsidies.  A carbon price will start to offset indirect subsidies (the cost to society of air pollution and carbon emissions) but direct subsidies (cheap govt loans, tax exemptions, export subsidies, etc.) have to be eliminated. 

Those steps will be enough for the next 10 years.  Transitioning electricity generation to renewables and our vehicle fleet to electric engines will cut emissions by 50%.  A 50 % decline over the next 15 years (eminently feasible) would be a compound annual decline of 5%.  It's what we have to do if we are to cut τ to as short a period as possible.  But if, as each year goes by, we see that emissions are not falling by the required 5-7% per annum, we will need to tighten the screws so that they do, for example by raising the annual increment in the carbon price from $3 to $5.  And we need to start working now on iron & steel, cement production, air transport and agriculture, so that in 10 years we can start cutting their emissions drastically too. 

It is unquestionably very close to a climate emergency.  Unless we act now, τ will be greater than T which means we will have lost control.   But we can act.  We are rational, we are informed, we have the technologies to slash emissions,.  Whether we'll cut τ enough remains to be seen.  Only serious, concerted, determined global action by everybody will do.  Think of that when you cast your next vote, or choose your next electricity supplier, or choose whether to have meat or vegetarian for your next meal.