Surface air temperature for June 2021
climate.copernicus.eu
climate.copernicus.eu
During the last century, CO2 emissions have been steadily rising year-over-year, in line with population growth across the globe. Given that this trend is now stalling naturally, the warming trend should follow suit. This leads me to the question: How bad is the "do literally nothing" scenario really?
Please see David Attenborough's "A life on our planet" (Netflix) what exactly may happen and what to do before it's too late: https://www.youtube.com/watch?v=KglanVLBVrc
Including 0 on the graph could be misleading too.
Page 8 of this report shows for millions of years together with explanations of some extinction events:
http://burro.case.edu/Academics/USNA229/impactfromthedeep.pd...
"If this trend continues, by the end of the next century atmospheric CO2 would approach 900 ppm—just below levels during the Paleocene thermal extinction 54 million years ago."
That's my point. It won't continue. Nothing grows to infinity. CO2 levels are rising due to an increase in emissions year-over-year. This increase is guaranteed to stop on its own. We don't know what happens if emissions stabilize at current levels. Perhaps CO2 concentration will continue to rise for a while, perhaps it will stabilize rather quickly. Absent any other factors, the long term trend is always for CO2 levels to (slowly) sink.
If I naively extend the following correlation, just going from 420 to 520 would require adding another 30 Gt of CO2 of annual emissions (almost doubling current levels):
https://www.climate.gov/sites/default/files/CO2_emissions_vs...
That amount represents the economic jump from the 1950s to now. Not inconceivable, but also not foregone.
> ...atmospheric CO2 would approach 900 ppm—just below levels during the Paleocene thermal extinction 54 million years ago"
Name-dropping an extinction event in this context is rather unwarranted, considering that those 900ppm were preceded by a slow descent from 1500ppm.
Lots of countries are looking to go from 1950's economy to modern standards, many live in rural areas that develop etc.
Why do you believe CO2 tends to drop? The accumulated CO2 don't follow emission drops in the graph. CO2 may linger for decades to hundreds of years.
Humanity is driving faster downhill without any brakes.
Same problem, you're name-dropping an extinction event which has, at best, a speculative relation to climate change in general and CO2 levels in particular. Certainly you will find such events where changes in CO2 coincide with extinction, but you will also find events where they don't.
> Lots of countries are looking to go from 1950's economy to modern standards, many live in rural areas that develop etc.
That is true and I'm not ruling it out, but that then begs the question what difference (if any) the comparably small population of already developed countries could make by curbing their emissions.
> Why do you believe CO2 tends to drop?
The cycles of the past million years. After every sudden peak, CO2 levels drop... until the next peak.
> The accumulated CO2 don't follow emission drops in the graph.
For one, there have been no sustained drops in emissions. Secondly, these graphs have different smoothing functions applied to them. Still, they do track each other pretty closely. Around the time of WW2, you see several years of constant CO2 levels, despite increasing cumulative emissions.
> Humanity is driving faster downhill without any brakes.
That's the mental image you like to use. I like to use this one:
https://nolanlawson.github.io/fronteers-2016/img/discostu.jp...
> Those CO2 peaks mark descents into Ice Ages and cataclysmic events during millions of years.
I was referring to the interglacial cycles, these are not cataclysmic per se.
https://www2.atmos.umd.edu/~zeng/papers/Zeng03_glacialC.pdf
As for the descent into an ice age, according to the interglacial cycle, we were right on schedule for that. Perhaps our ancestors will thank us for averting it?
https://principia-scientific.com/why-the-current-interglacia...
https://climate.nasa.gov/news/2948/milankovitch-orbital-cycl...
Anyways, seems humanity is going into very intense periods going forward.
https://www.quora.com/When-will-the-world-s-oceans-lose-thei...
https://www.noaa.gov/education/resource-collections/ocean-co...
https://knowledge.insead.edu/blog/insead-blog/the-ocean-cann...
The rise of CO2 concentration isn't accelerating, or if it is, then to a far smaller degree than emissions have increased.
Even a cursory argument should make it obvious this is untrue: CO2 is cumulative, so emitting the same amount year over year will continue increasing warming.
Looking at this graph, if annual emissions stay roughly constant (around WW2) then CO2 levels also stay roughly constant, even though cumulative emissions are rising:
https://www.climate.gov/sites/default/files/CO2_emissions_vs...
You can argue that at current levels of annual emissions this isn't the case, but then I would like to see some evidence.
I can (sort of) make sense of it the other way around: The rise in atmospheric CO2 is the derivative of emissions per unit of time. This isn't true, but maybe it works as a model. It then follows that the derivative of a constant function (i.e. emissions over time stay constant because growth has stopped naturally) is zero (i.e. there is no rise in concentration). In that case, we simply agree.
This is modulo natural sources and syncs, of course, but CO2's half-life in the atmosphere is long enough that on the immediate timescale those influences can be ignored. We're not going to reach a new steady-state for some time even if emissions remain constant; rather than constant emissions resulting in constant concentration, constant emissions will result in concentration rising at a constant rate on any near-term (< century) timescale.
On the immediate time scale, anything can be ignored. Climate change is not about what's going to happen immediately.
Excess CO2 "officially" has a half-life of around 20 years, but this begs the question as to what "excess" actually means. If an increase in CO2 leads to an increase in plant growth and therefore an increased capacity of further uptake down the road, that excess may now in fact be required to maintain plant growth. Those "excess plants" can't wait for all the other plants to decompose and return to the carbon cycle, because that happens on a much longer timescale.
I don't see that this aspect is accounted for in the IPCC models: https://gmd.copernicus.org/articles/11/1887/2018/
Activists often like to point at the high per-capita rate of emissions of people in developed countries, but that ignores that there are far fewer such people and that their birth rates are usually below replacement levels. The climate itself obviously doesn't care about emissions per-capita.
This is also another reason why the crux of the problem is not with developed countries. They have all the wealth to optimize and reduce their emissions, but if the developing world is bound towards a similarly high standard of living, that can't really make much of a difference. If anything, the focus should be on making that development as "clean" as possible, which is not the same problem as reducing emissions at home, except for some technological overlap. Alternatively, developing countries could simply be denied our standard of living through international policy. That, of course, would be an injustice.
By far the most emissions, now and historically, are in developed countries. The cause of our current problems is the failure of developed countries, the US in particular, to act.
If you want to play the blame game for historical emissions, sure, the developed countries are the biggest culprits. That however has no bearing on future emissions.
No policy of today will undo historical emissions, except maybe a significant sequestration effort, but I don't see any of that in the broader discussion. It's all about how the US needs to reduce current emissions, which would still only amount to 15% of worldwide emissions if eliminated completely.
We also can see that the majority of current emissions are coming out of developing countries, unless for some reason you want to count China into the developed countries.
It's not like the people who like climate change driving activity are living on a different planet.
it might work.
I think if we got disarmed their narrative of power and implacability, and realized our own power, the issue would be settled promptly. The truth is, most Americans are concerned about climate change and have been for awhile.
It’s too late and the price would have to be too high ($100s per ton) to be a main driver. We squandered those opportunities long ago.
It needs to be paired with robust policy to develop, deploy, support, and mandate decarbonization across sectors.
Markets move to slow to save us.
https://www.ventusky.com/?p=13;-8;1&l=temperature-2m&t=20210...
Can be handy for your area
Also, have a look at the climategate-scandal to see the mindset of the scientists behind the adjustments of raw data sets to show warming where there is none.
https://pdf4pro.com/amp/view/the-climategate-emails-lavoisie...
Here´s some quotes from the link:
“I’ve just completed Mike’s [Mann] Nature trick of adding in the real temps to each series for the last 20 years (i.e. from 1981 onwards) and from 1961 for Keith’s [Briffa] to hide the decline.”
—Dr. Phil Jones, Director of the Climatic Research Unit, disclosed Climategate e-mail, Nov. 16, 1999
“Also we have applied a completely artificial adjustment to the data after 1960, so they look closer to observed temperatures than the tree-ring data actually were…”
—Dr. Tim Osborn, Climatic Research Unit, disclosed Climategate e-mail, Dec. 20, 2006
“…If you look at the attached plot you will see that the land also shows the 1940s warming blip (as I’m sure you know). So, if we could reduce the ocean blip by, say 0.15 deg C, then this would be significant for the global mean—but we’d still have to explain the land blip…”
—Dr. Tom Wigley, University Corporation for Atmospheric Research, on adjusting global temperature data, disclosed Climategate e-mail to Phil Jones, Sep. 28, 2008
“We, therefore, do not hold the original raw data but only the value-added (i.e. quality controlled and homogenized) data.”
—Climatic Research Unit web site, the world’s leading provider of global temperature data, admitting that it can’t produce the original thermometer data, 2011
Longer term graphs should raise concern for existing life today:
https://johnenglander.net/chart-of-420000-year-history-tempe...
And why: https://climate.nasa.gov/evidence/