What will be Mauna Loa CO2 level for December 2030?

[crandles]

Data:
Month____Value____8 year increase
Dec 2005   380.31   15.8
Dec 2006   382.02   14.72
Dec 2007   384.19   15.93
Dec 2008   385.79   15.96
Dec 2009   387.63   16.21
Dec 2010   389.99   16.01
Dec 2011   392.06   15.89
Dec 2012   394.57   16.89
Dec 2013   397.03   16.72
Dec 2014   399.15   17.13
Dec 2015   402.06   17.87
Dec 2016   404.64   18.85
Dec 2017   407.00   19.37
Dec 2018   409.27   19.28
Dec 2019   411.98   19.92
Dec 2020   414.26   19.69
Dec 2021   416.71   19.68
Dec 2022   418.95   19.8

So business as usual with continuing increases in the rate of increase might suggest around ~22ppm higher over the next 8 years so somewhere around 441.

But:
1. World might take action to reduce emissions? which might reduce this.
2. Feedback effects might start to take effect? could increase this.
3. Current ending? La Nina may mean current value is below trend at present and it isn't clear whether there will be El Nino or La Nina for Dec 2030 measurements. Likely increase.
4. Other climate oscillations.
5 Any other effects you think may be important.

Please feel free to explain your poll answer whether in terms of importance of items listed above or otherwise.

[kassy]

1. We are growing for some more years so that effect won´t be big.
2. Oceans will warm and forests will decline so we will lose some more sink on the way.

So maybe a bit higher but i have not decided yet.

[gerontocrat]

435

A slight reduction from the current x³ extrapolation in the attached graph due to -
- some reduction from late 2020's in demand for fossil fuels from:-
         - Solar+Wind growth and growth in EVs ,
         - impact of increasing climate change disruption to world economic growth,
offset by
- continued increase in methane ppb concentration,
- decline in the ocean and land CO2 sinks.

Mind you, chuck in new pandemics, water wars, China/US cold war getting hotter, tipping points and God knows what else and you might as well turn to Nostrodamus, The Book of Revelations and the Farmers' Almanac.

click graph to enlarge

[oren]

I can barely read the chart but it will be exactly where the extrapolation is shown, as no one seems to care enough, and BAU goes on. Picked 438.5-439.5

[Tor Bejnar]

I figure we’ll do one bin less horrific, oren

[Stephan]

I chose the 437 ppm bin by extrapolating the long-term increase rate graph.

[Richard Rathbone]

BAU is low 440s but I think the rate of increase will flatten. There'll be quite large reductions in CO2 from electricity, but not much switch from fossil to electricity for heat and industry.

I'll pick the constant rate of increase = 439

(I'd have it peaking around 470 in the 2060s on my modestly optimistic trajectory)

[trm1958]

440.50-441.49
I'm getting cynical about AGW

[D-Penguin]

An increase of ~3.00 ppm each year over the past 10 years therefore add 24 ppm over the next 8 years gives 444 ppm plus 2 ppm for increased industrial activity and feed-backs over-and-above any savings. 446 ppm in 2030.

[A-Team]

no one seems to care and BAU goes on.
i'm getting cynical about AGW
going high on forecast

Indeed. No one in my contact sphere is restraining themselves in any way, even those working for environmental groups. They're taking long trips in low mileage campers, airplane flights for inessential travel, organic winter vegetables flown in from Chile, mitigation by planting trees that would have been planted anyway only to burn, and lining up bolt-holes (a rabbitry term) in New Zealand, Iceland, Costa Rica and Vermont.

No sensible rabbit would consider depredating a fenced garden without preparing a hasty hidden exit. And that is what the leadership is doing; they see gardening forums as doom-scrolling.

Looking myself for online guidance, the current priorities seem to be isolation, food growing and currently too-cool climate. Since climate change cannot really be avoided, the emphasis is on physical isolation, avoiding the billions of desperate migrants.

https://earth.org/best-places-to-live-to-avoid-climate-change/

I read up on the 1947 Partition of India to get a sense of poorly administered mass migration. It was horrific on a vast scale and still ongoing. The wealthy of today want no part of anything like that, such as staying in Europe.

https://en.wikipedia.org/wiki/Partition_of_India

There's never enough money to go round so only a select few can afford sailing yachts and private planes. That is, it's not so easy to get to New Zealand during or after a crash. And they might not take you even if some prior asset foothold had been established.

I don't fancy Vermont. The soil is terrible, the forests will all burn and it's too accessible. There are some 175 million increasingly desperate people in Central American alone. Could that be offset by 175 million of us moving to 100x200 sq mile Costa Rica (plus Panama and PR)?

Build a 30 foot wall and they will bring a 31 foot ladder? Urban myth, they bring a cordless sawzall or angle grinder instead. It takes only minutes to cut through the border barrier’s steel-and-concrete bollards; some 3,272 instances of that by March 2022 in Arizona alone. The border is 3000 km long with some 300 million crossings per year.

I don't think it will play out like this -- forced voluntary simplicity, mandatory ebikes, policing brutality. Too many trophy homes end up stranded assets.

More likely, another engineered virus will 'escape' and take out the 95% who were told to take the latest 'flu' vaccine but didn't (left out of the loop). Too much was learned by too many from covid19.

So, which CO2 pathway are we on etc, deserves separate consideration of sudden mass population depletion scenarios.

Forget methane, the key variable is the help. Reagan raised this back in the 1970's. If only the privileged are left, who milks the cows? Deplorables are still needed, just not too many.

Climate change doesn't stop just because emissions and consumption plummet, various tipping points are already baked in. However it surely moderates over what it would have been under continuing BAU.

[crandles]

An increase of ~3.00 ppm each year over the past 10 years

24.65 is the largest rise over 10 years (from Dec to Dec with highest being 10 years to Dec 2021).

Why say something like that when the information is laid out in the opening post? (You are entitled to your own opinion but not your own facts. If your facts look wrong, doesn't that undermine how other people see your opinion?)

[crandles]

I am rather shocked at the proportion of votes below 441 compared to above it.

List items 4 and 5 could be up or down, best guess would seem to be about 0 effect.

feedbacks (no 2 on list) - if there is slow steady effect that is already built into the pattern. Short sharp changes are not impossible eg Storegga slide type event but multi-thousand year event happening in 8 years is unlikely. There could be smaller more frequent such effects but if we haven't really noticed any since Keeling curve measurements 1958, then likely small and/or infrequent. Basically 8 years is not a lot.

Emissions (no 1 on list). Like feedbacks, 8 years is not a lot of time. Renewables gaining ground in electricity production and cars may be beginning to move to EV faster but there are other areas like heating and industry that are harder and lot of people in poorer countries are trying to develop. Hopefully some reduction in the emission trends but how much can we expect in a mere 8 years? Some yes, but I fear it will only amount to 1 or 2 ppm over the 8 years,

ENSO This seems like the largest effect to me and while there might be a strong La Nina just before Dec 2030, a 1 or 2 ppm increase from this seems likely.

I voted for 441 hoping emissions reductions would counter ENSO effects.

But I am surprised how few have gone for more than 441 so far. Maybe I am too pessimistic on emissions reductions and solar, wind and electric cars will sharply accelerate in just a short 8 year period, without industrialization of developing countries and the demand this will create spoiling this.   

[Sciguy]

The energy transition is well underway and carbon emissions either peaked in 2019 or will peak in the next couple of years.  After that, carbon emissions will start decreasing rapidly as fossil fuels become uneconomic.

In addition, the US has start spending billions to cap abandoned oil wells, reducing methane emissions significantly.  As China coal mining peaks later this decade, methane emissions from China will reduce as well.

Electric vehicles have taken off and will be outselling fossil fuel powered vehicles by 2030 as well.  The US has funded billions for new chargers, school bus fleets, postal vehicles and other government vehicles.  The auto manufacturers keep introducing new EV models and there are huge tax incentives for buyers.

In short, the curve on emissions is going down.  Simple extrapolations make no sense when you look at the carbon emissions sources.

I chose the 435 ppm bin.