Uploaded March 2026 | Updated September 2026, 2 weeks ago
Sahara Desert Greening in AHPs (African Humid Periods) in the Paleorecords - what is going on today?
I chat about periods in the paleorecords when the Sahara was green. Although we are seeing some greening in parts of the Sahara today from extreme precipitation events and planting of "The Great Green Wall", we are not seeing an overall shift but are still getting an overall increase in desert area.
Please donate to PaulBeckwith.net to support my research and videos connecting the dots on abrupt climate system mayhem.
References
Map of vegetation zones (ecozones: ecoregions) across the planet (great map)!
en.wikipedia.org/wiki/Lists_of_ecoregions#/media/File:Vegetation.png
Wikipedia list of global ecoregions
en.wikipedia.org/wiki/Lists_of_ecoregions
Peer-reviewed paper in scientific journal Climates of the Past:
Pattern scaling of simulated vegetation change in northern Africa during glacial cycles
cp.copernicus.org/articles/21/773/2025/cp-21-773-2025.pdf
Abstract.
Over the last hundreds of millennia, natural rhythms in Earth’s astronomical motions triggered largescale climate changes and led periodically to humid conditions in much of northern Africa. Known as African Humid Periods (AHPs), such times sustained vast river networks, vegetation, wildlife, and prehistoric settlements. The mechanisms, extent, and timing of the changes remain poorly constrained. Although AHPs along glacial cycles are recognizable in marine sediment records, the related land cover changes are difficult to reconstruct due to the scarcity of
proxy data over the continent. Moreover, most available information covers only the latest AHP during the Holocene. Here we use a comprehensive Earth system model to look at
additional, much earlier, possible cases of AHPs. We simulate the full last glacial cycle, aiming to reproduce the last four AHPs as seen in available proxies. The simulated AHPs
seem in broad agreement with geological records, especially in terms of timing and relative strength. We focus on the simulated vegetation coverage in northern Africa, and we detect
a dominant change pattern that seems to scale linearly with known climate forcing variables. We use such scaling to approximate northern African vegetation fractions over the last eight glacial cycles. Although the simple linear estimation is based on a single mode of vegetation variability (that explains about 70 % of the variance), it helps to discuss some broad-scale spatial features that had only been considered for the Holocene AHP. Extending the climate simulation several
millennia into the future reveals that such (paleo-based) pattern scaling breaks when greenhouse gases (GHGs) become a stronger climate change driver.
Query: Tell me about the greening of the Sahara Desert:
perplexity.ai/search/tell-me-about-the-greening-of-juE.YzTeS0qpG6rSk.D.sw
Peer-reviewed scientific paper in journal Climate Past
Northward Shifts of the Sahara Desert in Response to Twenty-First-Century Climate Change
journals.ametsoc.org/view/journals/clim/36/10/JCLI-D-22-0169.1.xml
SIGNIFICANCE STATEMENT:
Given that sub-Saharan Africa is one of the most vulnerable regions to climate
change, the Sahara’s expansion would bring unexpected health risks to billions of people. It is thus vital to understand its robust response to global warming. However, previous studies are merely focused on using a simple precipitation threshold as the definition criterion to estimate the varying size of the Sahara Desert. In addition, significant uncertainty in precipitation projections also limits relevant investigations of the Sahara’s future responses. Here, by developing an ensemble Bayesian discriminant analysis approach, we could provide an objective basis for desert identification under
large inter-model uncertainty. Further, we find significant northward shifts of both the Sahara and the Sahel, which may induce higher risks of drought over the northwest of North Africa.
Paper: Analysis of the spatial-temporal patterns of vegetation, precipitation, land surface temperature, and soil moisture across the Sahara-Sahel Great Green Wall region using remote sensing data.
https://journals.gmu.edu/jssr/article/view/4223
Scientific Report: Expansion of the Sahara Desert and shrinking of frozen land of the Arctic
pmc.ncbi.nlm.nih.gov/articles/PMC7057959/pdf/41598_2020_Article_61085.pdf
Please donate to PaulBeckwith.net to support my research and videos connecting the dots on abrupt climate system mayhem.
Please subscribe to my YouTube channel. As well as my website, and YouTube, you can find me on Patreon, Facebook, Twitter/X, LinkedIn, Instagram, Reddit (multiple climate channels within), Quora, TikTok, Discord, Mastodon, Twitch, Vimeo, Bluesky, TruthSocial, Threads, Substack, Tumblr, Pinterest, etc...
Sahara Desert Greening in AHPs (African Humid Periods) in the Paleorecords - what is going on today?
I chat about periods in the paleorecords when the Sahara was green. Although we are seeing some greening in parts of the Sahara today from extreme precipitation events and planting of "The Great Green Wall", we are not seeing an overall shift but are still getting an overall increase in desert area.
Please donate to PaulBeckwith.net to support my research and videos connecting the dots on abrupt climate system mayhem.
References
Map of vegetation zones (ecozones: ecoregions) across the planet (great map)!
en.wikipedia.org/wiki/Lists_of_ecoregions#/media/File:Vegetation.png
Wikipedia list of global ecoregions
en.wikipedia.org/wiki/Lists_of_ecoregions
Peer-reviewed paper in scientific journal Climates of the Past:
Pattern scaling of simulated vegetation change in northern Africa during glacial cycles
cp.copernicus.org/articles/21/773/2025/cp-21-773-2025.pdf
Abstract.
Over the last hundreds of millennia, natural rhythms in Earth’s astronomical motions triggered largescale climate changes and led periodically to humid conditions in much of northern Africa. Known as African Humid Periods (AHPs), such times sustained vast river networks, vegetation, wildlife, and prehistoric settlements. The mechanisms, extent, and timing of the changes remain poorly constrained. Although AHPs along glacial cycles are recognizable in marine sediment records, the related land cover changes are difficult to reconstruct due to the scarcity of
proxy data over the continent. Moreover, most available information covers only the latest AHP during the Holocene. Here we use a comprehensive Earth system model to look at
additional, much earlier, possible cases of AHPs. We simulate the full last glacial cycle, aiming to reproduce the last four AHPs as seen in available proxies. The simulated AHPs
seem in broad agreement with geological records, especially in terms of timing and relative strength. We focus on the simulated vegetation coverage in northern Africa, and we detect
a dominant change pattern that seems to scale linearly with known climate forcing variables. We use such scaling to approximate northern African vegetation fractions over the last eight glacial cycles. Although the simple linear estimation is based on a single mode of vegetation variability (that explains about 70 % of the variance), it helps to discuss some broad-scale spatial features that had only been considered for the Holocene AHP. Extending the climate simulation several
millennia into the future reveals that such (paleo-based) pattern scaling breaks when greenhouse gases (GHGs) become a stronger climate change driver.
Query: Tell me about the greening of the Sahara Desert:
perplexity.ai/search/tell-me-about-the-greening-of-juE.YzTeS0qpG6rSk.D.sw
Peer-reviewed scientific paper in journal Climate Past
Northward Shifts of the Sahara Desert in Response to Twenty-First-Century Climate Change
journals.ametsoc.org/view/journals/clim/36/10/JCLI-D-22-0169.1.xml
SIGNIFICANCE STATEMENT:
Given that sub-Saharan Africa is one of the most vulnerable regions to climate
change, the Sahara’s expansion would bring unexpected health risks to billions of people. It is thus vital to understand its robust response to global warming. However, previous studies are merely focused on using a simple precipitation threshold as the definition criterion to estimate the varying size of the Sahara Desert. In addition, significant uncertainty in precipitation projections also limits relevant investigations of the Sahara’s future responses. Here, by developing an ensemble Bayesian discriminant analysis approach, we could provide an objective basis for desert identification under
large inter-model uncertainty. Further, we find significant northward shifts of both the Sahara and the Sahel, which may induce higher risks of drought over the northwest of North Africa.
Paper: Analysis of the spatial-temporal patterns of vegetation, precipitation, land surface temperature, and soil moisture across the Sahara-Sahel Great Green Wall region using remote sensing data.
https://journals.gmu.edu/jssr/article/view/4223
Scientific Report: Expansion of the Sahara Desert and shrinking of frozen land of the Arctic
pmc.ncbi.nlm.nih.gov/articles/PMC7057959/pdf/41598_2020_Article_61085.pdf
Please donate to PaulBeckwith.net to support my research and videos connecting the dots on abrupt climate system mayhem.
Please subscribe to my YouTube channel. As well as my website, and YouTube, you can find me on Patreon, Facebook, Twitter/X, LinkedIn, Instagram, Reddit (multiple climate channels within), Quora, TikTok, Discord, Mastodon, Twitch, Vimeo, Bluesky, TruthSocial, Threads, Substack, Tumblr, Pinterest, etc...
