Things are getting better part 2

[GregLocock]

Estimates of crop yields in USA out to 5 deg C of warming.

https://www.nature.com/articles/s41598-025-90254-2

 

[TugboatEng]

Meta-analysis, ugh. Let's take the same bad data from before and try to come up with better results.

 

[GregLocock]

Shrugs, the author is the guy who proved that Mann's hockey stick analysis was bad maths (and rotten science but that's a separate issue). If anyone is going to do meta analysis i'd rather it was him.

 

[dik]

Things may be getting worse in other areas. Winnipeg is likely to improve. We used to have a week or so of -35C to -40C weather in January and February. For the last 20 years it's hardly gotten below -30C.

 

[btrueblood]

I like how he pointed out the C14 curve was forced to be nonlinear, affecting marginal yields, versus just fitting the data as he did.

 

[JoshPlumSE]

Dik: Things may be getting worse in other areas. Winnipeg is likely to improve. We used to have a week or so of -35C to -40C weather in January and February. For the last 20 years it's hardly gotten below -30C.

The general hypothesis that warmer weather leads to better growing seasons for farmers is not very controversial. Now, that's assuming that you still have adequate water supplies, of course.

In general, it's drought and colder weather that hurts food production. Unless droughts greatly increase due to global warming (a dubious hypothesis), the net effect (at least in terms of food supply) will almost certainly be beneficial.

 

[GregLocock]

"Under elevated CO2 concentrations, plants use less water during photosynthesis. Plants have openings called stomata that allow CO2 to be absorbed and moisture to be released into the atmosphere. When CO2 levels rise, plants can maintain a high rate of photosynthesis and partially close their stomata, which can decrease a plant’s water loss between 5 and 20 percent. "

How Climate Change Will Affect Plants

While elevated levels of CO2 can help plants grow, the impacts of climate change mean it’s not all good news for the plant world.

news.climate.columbia.edu

 

[dik]

In general, it's drought and colder weather that hurts food production.

Yup... but if you're not a plant, -30C is better than -40C.

 

[JoshPlumSE]

Dik -

Correct me if I'm wrong. But, weren't we talking about crop yields and food supply?

Honestly, even if we were talking about the massive levels of warming like you suggest (which I don't think is very realistic). Don't we know (or strongly suspect that the Arctic and Antarctic are where the largest warming is expected to occur due to CO2 emissions? Whereas the equator would see much less warming. This would mean that it would only make the world BETTER suited for human habitation.

 

[dik]

Correct me if I'm wrong. But, weren't we talking about crop yields and food supply?

I suspect with climate change, the crop yields in Manitoba will slowly improve, caused by the change in temperatures. On the downside, things will likely change for the worse in other areas of the world.

 

[GregLocock]

Oh the Arctic is getting warmer. The Antarctic is getting colder. In between is in between.The theory that can explain everything has been used to 'explain' why GW was to blame for extended sea ice in Antarctica in 2014, and is also to blame for reduced sea ice in the Antarctic now (even though it is colder). Shock horror it may be that variability is a thing and that GW is not the control knob.

Here's a rather tricky graph. They've used the temperature of the tropics as a baseline, and then subtracted the temperature of the Arctic and Antarctic from that. So Antarctica is getting cooler relative to the tropics, and the Arctic is getting warmer. I strongly suggest you read all the bits of text.

 

[dik]

Oh the Arctic is getting warmer.

...four times faster than the rest of the world.

 

[GregLocock]

And Antarctica is getting colder. The World is a Very Big Place and there is region to region variation. I'm surprised you didn't know that.

 

[dik]

I did, but it's just not relevant other than how it affects climate change.

and in other places:

Global glacier melt is accelerating, new study finds

A new study published in Nature finds ice is melting at a ‘concerning’ rate, with repercussions for sea-level rise.

www.aljazeera.com

 

[SnTMan]

It is well known that everyplace is warming faster than every other place.

LOL

 

[GregLocock]

I'll assume dik's study is this one

"
The research shows the world's glaciers collectively lost 6.542tn tonnes of ice between 2000 and 2023, causing an 18mm (0.7in) rise in global sea levels. The world's glaciers lost an average of 273bn tonnes of ice every year -- the equivalent of 30 years of water consumption by the entire global population.

The assessment, led by scientists from the University of Edinburgh and the University of Zurich, found that so far this century, glaciers have lost approximately 5% of their total volume. Regional losses were highly variable; the Antarctic and subantarctic islands lost 2% of their volume but central Europe's glaciers lost 39%.

"These numbers are staggering. They serve as a reminder that things are changing fast in some regions," said Prof Noel Gourmelen, the co-lead author of the study and personal chair of Earth observation at the University of Edinburgh's school of geosciences. A stark contrast in the amount of ice lost each decade was also discovered, with 36% more ice having melted between 2012 and 2023 compared with the previous decade."

so 5% of their volume is 18mm, therefore high school maths tells us that if every glacier completely melted, you'd get a bit over 1 foot of sea level rise. I don't know about you, but our typical interdaily tidal range is approximately 6 feet. So a 1 foot shift in that doesn't sound much. That is of course assuming the numbers in the summary are correct.

 

[JoshPlumSE]

Greg Locock: That is of course assuming the numbers in the summary are correct.

I have zero confidence that the numbers in the summary are correct....

For what it's worth, I just think the whole "science" behind this has gotten so tangled up with politics that it's practically worthless. I accept the basic premise.... that our rate of CO2 emissions has caused increased atmospheric CO2. And, that this increase in CO2 will likely result in a warming trend.

What I reject is all the "doomsday" scenarios that are cooked up around this. Basically anything Greta Thundberg has ever said.

It is 100% clear that humanity has had an incredible effect on basically all areas of our planet. We don't have bison roaming the plains of the midwest anymore. There are no Grizzly bears in CA anymore (to my knowledge). Lot of species have be affected and may be at risk of going extinct. Lots of other species have adapted and are doing well.

The problem (as I see it) is that we have a decent portion of our population who's religion is akin to a worship of nature or Gaia. That essentially, we are all sinful because we don't live in balance with nature anymore. They will do almost anything to oppose development, growth and progress. These people have seized upon Global Warming and will not let it go.

I'm not much of a "end times" religious zealot. But, if there is a "whore of Babylon" that is leading people astray from God and towards a false religion then it's probably Al Gore.

 

[GregLocock]

Oh I agree CO2 is a small but significant contributor to the greenhouse effect which does seem to be causing a slight increase in temperature, vastly outweighed by water vapor and clouds, which seem to be changing but at least in the case of clouds seem to be incalculable in the models.

The major made up nonsense is
(a) we are in a climate catastrophe
(b) there will be a bigger-er climate catastrophe due to CO2 (there will be one due to a meteorite, at some point that is certain, and probably one due to vulcanism)
(c) reducing CO2 in some countries will somehow reduce or slow the increase in temperatures (particularly when those CO2 emissions are merely exported elsewhere)
(d) high global temperatures are bad (no to date high CO2 and temps have helped, on balance)
(e) we can directly compare proxies and thermometers
(f) the CMIP models
(g) the various meteorological organisations corrections to the ground based temperature record are being done in an acceptable fashion
(h) ground based temperature readings are a reliable guide to global average temperature
(i) we know anything much about the heat content history of the seas
(j) global average temperature is meaningful at a human or even national level
(k) attribution 'science'
(l) public funding of industrial green projects makes sense
(m) The wind+solar+storage model for regional power grids provides cheap and reliable unsubsidised electricity
green hydrogen
(o) carbon capture
(p) nukes are the most expensive form of despatch-able power (see m and I suppose n)
(q) we are running out of coal oil gas uranium lithium rare metals. (We are pushing it with copper, zinc and to my surprise phosphate).
(r) current global average temperatures are unusual for an interglacial
(s) The Great Barrier Reef tells us much except what the local water temperature as been up to for the past year.

 

[GregLocock]

Even the eng-tips page renderer thinks green hydrogen is a bad idea!

 

[dik]

For what it's worth, I just think the whole "science" behind this has gotten so tangled up with politics

That's the problem... hit the nail on the head. Addressing climate change is costly, and will affect lifestyles. See what it's done to California, and there may be more to come.