Essay by Eric Worrall
Heads I win, tails you lose…
With CO2 Levels Rising, World’s Drylands Are Turning Green
Despite warnings that climate change would create widespread desertification, many drylands are getting greener because of increased CO2 in the air — a trend that recent studies indicate will continue. But scientists warn this added vegetation may soak up scarce water supplies.
BY FRED PEARCE • JULY 16, 2024
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And Australia is far from alone. From Africa’s Sahel to arid western India, and the deserts of northern China to southern Africa, the story is the same. “Greening is happening in most of the drylands globally, despite increasing aridity,” says Jason Evans, a water-cycle researcher at the Climate Change Research Centre of the University of New South Wales in Sydney, Australia.
What is going on? The primary reason, most recent studies conclude, is the 50-percent rise in carbon dioxide concentrations in the atmosphere since preindustrial times. This increased C02 is not just driving climate change, but also fast-tracking photosynthesis in plants. By allowing them to use scarce water more efficiently, the CO2-rich air fertilizes vegetation growth in even some of the driest places.
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The negative impacts of hotter, drier climates have not gone away; but in most arid lands this CO2 fertilization effect is proving more powerful. This supercharging of plant growth seems unlikely to be short-lived if fossil-fuel burning causes atmospheric concentrations of CO2 to continue rising. A new modeling studypublished last month found that it will, if anything, become more marked in the coming decades. “Most of the global drylands are projected to see an increase in vegetation productivity,” says Evans, a coauthor of the study.
…Water is not the only potential limiting factor in plant growth in arid lands. The availability of nutrients, particularly nitrogen, is another. That raises questions about whether the benefits of CO2 fertilization will continue to increase. But recent climate modeling suggests that the greening of drylands is unlikely to slow before mid-century and may speed up.
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So is this all good news? Far from it, ecologists warn. Most obviously, the greening created by agricultural irrigation of fields can play havoc with scarce water reserves and obliterate valuable arid-land ecosystems
Read more: https://e360.yale.edu/features/greening-drylands-carbon-dioxide-climate-change
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What can I say? The climate science prediction that CO2 would cause deserts to expand turns out to be dead wrong – but it’s still bad news.
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Gee, it seems warmer is better! At least for the Sahara desert.
Sahara Greening 5,000 to 10,000 years ago:
The main climatic effect of precession is to shift the season when the Earth has its closest pass to the Sun (perihelion) — the so-called precession of the equinoxes. Today, perihelion occurs in northern hemisphere winter but at 10,000 years ago (half of a precession cycle) it occurred in northern hemisphere summer, and summer radiation over North Africa was about 7% higher than it is today.
Orbital precession greatly influences North African climate because it controls the strength and northward penetration of the monsoonal rains (Kutzbach, 1981; Liu et al., 2006). Strengthening summer-season solar radiation causes the North African landmass to heat up relative to the adjacent Atlantic Ocean due the lower thermal inertia of the land surface relative to the upper ocean mixed layer. The warmer land mass creates a broad low pressure zone, driving the inflow of moist air from the tropical Atlantic. The resulting summer monsoonal rains nourish the landscape.
During winter, the land cools relative to the ocean and the winds reverse (one definition of a monsoon), returning dry conditions across North Africa. Since precession controls summer insolation, it effectively controls the amount and northward penetration of the monsoonal rains into North Africa. Simple atmosphere-only climate models have shown that a 7% increase in summer radiation, similar to what occurred during the AHP, results in at least a 17% increase in African monsoonal rainfall, and up to 50% if ocean feedbacks are included (Kutzbach and Liu, 1997).
https://www.nature.com/scitable/knowledge/library/green-sahara-african-humid-periods-paced-by-82884405/
See, this kind of moronic statement from ”scientists” really shits me.
Does that mean that any more greening is bad? That less greening is then good? That it was just perfect 200 years ago but any change up or down from that is bad?
Which is it? Breathtaking nonsense!!
Scientists write papers about observations of experiments.
Psychics who believe their crystal balls warn, but only for a price.
I’ve been listening to podcasts on the Bronze Age Collapse. Not just the Sea People’s fault. One factor posited is drought which in some places lasted 300 years before “recovering”.
If you’ve had dry conditions for 300 years why is conditions on increasing rainfall recovery and not climate change?
As an aside if the latest theories are correct then we’re heading for a similar collapse. Positive is that it affected different cultures differently some recovered very quickly.
Not to worry, Bill Gates is cutting down lots of trees to fix the problem. Another scientist looking out of all of us. /s
Most of the planet is not desert, or even land.
It’s sea.
Increased CO2 gives a boost there too. And that’s where the big changes occur. It’s the marine life that’s the basis of life on earth.
It seems Mr Worrall can’t entertain two ideas in his mind at the same time — 1) that the Greenhouse properties of CO2 are basic physics, and unrelated to its other properties, and 2) That climate change is a real phenomena, caused by man-caused emissions of 40 billion tonnes of CO2 annually due to the burning of fossil fuels. Why is does Mr Worrall have such difficulty grasping basic physics?
Because he observes what happens in the real world, rather than what happened in a laboratory ?
He has the ability to sense global mean temperature over the last 50 years and plot the results in his head? He’s as smart as you!😂
Global mean temperature –
that’s bullshit right there.
A well-calibrated bullshit detector is far more useful in the real world than temperature constructs Wazza.