Comments
Aardark235 t1_iw0o5jr wrote
CO2 emissions from energy production has grown 7x in the last 70 years at a near linear pace with only a minor deviation due to Covid. We will have far more emissions as the 80% of the population living in developing regions gain the wealth of the developed nations. I call BS on your citations.
Few countries are willing to sacrifice growth to promote a better earth. Witness how Americans were united in Saudi Arabia cutting oil production by 2% of global supply. Even the most fervent anti-climate change activists on Reddit were upset and felt now was not a good time to reduce emissions. It is never a good time and selfishness trumps altruism.
The promises made by politicians are empty lies.
grundar t1_iw1062v wrote
> I call BS on your citations.
Interesting. Would you care to critique the methodology of the Nature paper associated with the 1.8C estimate I cited?
Of note is that the first author of that paper is one of the drafting authors of the IPCC WGI report, so their scientific credentials are a little more than can reasonably be dismissed via "I call BS".
The other source is the International Energy Agency, set up by the OECD (rich countries) to provide data on energy in the aftermath of the 1973 oil crisis. They certainly have their flaws, one of the major ones is how they consistently underestimate the growth of renewable energy. Indeed, their scenarios from 5 years ago were far more pessimistic than their scenarios today, indicating that their overly-conservative bias has continued at least up until recently.
I know the data these sources are giving you feels wrong, but how the data feels is of limited value in a scientific discussion.
Aardark235 t1_iw18fs1 wrote
Did you even read that Nature Paper? It does not support your conclusion. Actually none of your links support your conclusions as realistic.
grundar t1_iw1mquy wrote
> Did you even read that Nature Paper? It does not support your conclusion.
Yes, I did read the Nature paper. Did you? What part of it do you feel disagrees with what I've said?
From the paper's Abstract:
> "Here we show that warming can be kept just below 2 degrees Celsius if all conditional and unconditional pledges are implemented in full and on time."
That's largely equivalent to the "all announced pledges" scenario at Climate Action Tracker (which, as I noted, should not be surprising, as there is overlap between the two groups of authors).
> Actually none of your links support your conclusions as realistic.
Do you have specific examples of where you believe I've mischaracterized specific references?
Or does what I've said simply feel wrong?
Without specifics, you're not making much of an argument here.
Aardark235 t1_iw28mgg wrote
Yes, if we can dramatically cut greenhouse gas emissions, we will have less greenhouse gas emissions. They also state that it isn’t a likely scenario as countries over promised and are under delivering, especially for the Big-3: USA, China, and India. You don’t read many science papers, do you?
There is no popular support for drastic cuts of fossil fuels in those countries. Witness the number of drilling rigs doubling under Biden and threats to punish Saudi Arabia for their slowdown of production. See India allying with Russia to save a little bit on crude oil. Observe China and their rapid growth and huge number of new power plants to supply the enormous middle class.
The pledges aren’t worth the paper they are written on.
grundar t1_iw3drdc wrote
> Yes, if we can dramatically cut greenhouse gas emissions, we will have less greenhouse gas emissions.
And as a result ~1.8C of warming.
I'm glad we now agree on the main content of my comment.
> They also state that it isn’t a likely scenario as countries over promised and are under delivering
Science requires specifics -- what specifically do they say that you interpret as that?
In general, the sources I've referenced do not say what actions are or are not probable, as they correctly recognize that predicting future human behavior is very hard and not their forte. What those sources do do is examine different scenarios, and analyze what would happen if each of the different scenarios were to occur.
Note that the IPCC and IEA in particular very explicitly call out that they are not saying which scenarios are more or less likely, only what will happen if those scenarios occur.
> There is no popular support for drastic cuts of fossil fuels in those countries.
Yes, which is why the key change is making clean energy cheaper than fossil energy.
Costs have dropped 10x for solar since 2010 (and 3x for wind), and as a result renewables are virtually all net new global power generation. Clean energy isn't suddenly booming because people have suddenly decided to self-sacrifice; it's suddenly booming because it's cheaper.
It's the same for moving away from oil; due largely to a 10x decline in the cost of batteries since 2010, EVs are projected to be a majority of the global car market by 2034 or even 2030 as reality races ahead of predictions.
That is what's driving the transition to clean energy and the subsequent emissions reductions -- economics.
Are national pledges questionable? They're not nothing, but I largely agree with you that they're shaky. The underlying technological and economic changes, though, are what is allowing those pledges to be kept with minimal sacrifice, and those technological and economic changes are the important drivers to keep an eye on.
Aardark235 t1_iw3x8ke wrote
Here is a better comparison of the current policies that will result in a +2.7C gain by the end of the century vs the unrealistic promises that we will almost immediately drop CO2 emissions in half.
https://www.cfr.org/backgrounder/paris-global-climate-change-agreements
grundar t1_iw4wrq3 wrote
> Here is a better comparison of the current policies
Did you not notice that they're referencing exactly the same analysis that I did in my original comment? They're linking to Climate Action Tracker, just like I did.
So...congratulations on coming full circle and finally agreeing with the references provided in my original comment, I guess.
While you're there, it may be instructive for you to note that while "current policies" result in 2.7C of warming, "current policies" as of 2018 would have resulted in 3.3C of warming, so "current policies" is very much a moving -- improving -- target.
Indeed, it's likely they'll put out a new analysis after COP27. Every previous major iteration has shown that estimated warming has declined -- for "current policies" as well as for scenarios taking into account pledges -- so it will be interesting to see if that continues to be the case after COP27 and if so how much. We'll see.
Aardark235 t1_iw50tqd wrote
You are a very optimistic person. For the sake of the planet, I hope you are right.
I am old and cynical for many valid reasons.
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grundar t1_iw04qvh wrote
> a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2).
Emissions are projected to peak around 2025 (source) and fall 15% by 2030 (source). Those figures would suggest ~33GtC through 2025 + ~51GtC through 2030, or another 84GtC used from the carbon budgets by 2030.
That would leave carbon budgets at 21GtC (1.5C), 116GtC (1.7C), and 251GtC (2.0C). At 9.5GtC/yr, that would be 2.2, 12, or 27 years of static emissions.
If emissions continued to decline linearly at that rate -- speculative, for sure -- they would go to zero around 2060, resulting in an additional 141GtC emissions and ~1.8C of warming (25GtC above the 1.7C budget but 110GtC below the 2.0C budget). Interestingly, 1.8C is also the current estimate if all announced targets are met.
All in all, this broadly confirms the evidence we've previously seen. The window of plausible climate futures is narrowing fairly substantially -- and generally towards the low end of what had been considered likely warming, which is great -- but 1.5C does not seem realistic anymore. 1.8C does have a few lines of evidence pointing towards it being realistic with significant effort, so it might be useful to think of that as the baseline target and spend some time explaining why every fraction of a degree better (or worse) than that will significantly reduce (increase) extreme weather, drought, famine, and suffering.