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We know the Earth has been through drastic climate changes in the past, so this thread is for books or articles which describe the process and broaden our understanding of climate.

For instance, Snowball Earth: The Story of the Great Global Catastrophe That Spawned Life as We Know It by Gabrielle Walker.

"In a discovery that challenges our understanding of Earth's ancient history, researchers have found evidence suggesting that Earth may have had a ring system that formed around 466 million years ago, at the beginning of a period of unusually intense meteorite bombardment known as the Ordovician impact spike.

The research team believes this localized impact pattern was produced after a large asteroid had a close encounter with Earth. As the asteroid passed within Earth's Roche limit, it broke apart due to tidal forces, forming a debris ring around the planet—similar to the rings seen around Saturn and other gas giants today.

"Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record," said lead study author Professor Andy Tomkins, from Monash University's School of Earth, Atmosphere and Environment. "We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris."

"What makes this finding even more intriguing is the potential climate implications of such a ring system," he said.

The researchers speculate that the ring could have cast a shadow on Earth, blocking sunlight and contributing to a significant global cooling event known as the "Hirnantian Icehouse."

This period, which occurred near the end of the Ordovician, is recognized as one of the coldest in the last 500 million years of Earth's history.

"The idea that a ring system could have influenced global temperatures adds a new layer of complexity to our understanding of how extra-terrestrial events may have shaped Earth's climate," Professor Tomkins said."

More information: Andrew G. Tomkins et al, Evidence suggesting that earth had a ring in the Ordovician, Earth and Planetary Science Letters (2024).

Journal information: Earth and Planetary Science Letters

Provided by Monash University

We've been very lucky so far.

"strengthening of monsoons in the Northern Hemisphere is thought to have played a significant role in increasing humidity across Africa, initiating conditions conducive to the growth of evergreen shrubs in the Sahara.

New research published in Climate of the Past has used climate model simulations to reconstruct the impact of this Saharan greening on the mid-latitudes during the middle Holocene. Dr. Marco Gaetani, Associate Professor at IUSS School for Advanced Studies in Pavia, Italy, and colleagues' numerical simulations identified Saharan greening having a year-long impact on atmospheric circulation in the Northern Hemisphere, especially during boreal summer when the African monsoon develops.

As such, regions in the Northern Hemisphere experienced abnormal climate, being warmer and drier in Scandinavia and North America, colder winters and warmer summers in western Europe, overall warming in central Europe, colder and rainier in the Mediterranean, plus warmer winters and colder summers with increased rainfall throughout the year in central Asia.

To account for these changes, the research team found that Walker Circulation (an atmospheric loop with rising air to the west as air moves westerly at higher latitudes and sinking air to the east as air moves easterly around the tropics) shifted westwards during the middle Holocene. This had important consequences for jet streams, causing the North Atlantic component to intensify and alter track in summer, followed by the North Pacific in winter.

They also identified a change in the North Atlantic Oscillation (where alterations in surface sea level pressure across this ocean basin lead to modified temperature and precipitation patterns on nearby continents) which shifted from positive to negative across both boreal winter (December to February) and summer months."

More information: Marco Gaetani et al, Mid-Holocene climate at mid-latitudes: assessing the impact of Saharan greening, Climate of the Past (2024).

Journal information: Climate of the Past

The above is relevant today, as Africa is planting a green wall of trees from coast to coast below the Sahara, and these will spread moisture to the interior. The Nile is now dammed by the Aswan Dam which holds back a new reservoir, and this has caused water to seep into the aquifer and re-emerge in new oases.
While desertification is spreading, seasonal growth in desert scrub terrain is eaten ravenously by pastured animals, and grazing is the main reason why the edges of the Sahara are not greener.
If grazing were restricted in some areas, and moisture continued to improve, the Sahara could be a lot greener than it is; which would increase the wealth of the Sahel countries, those bordering the desert to the south, which are among the poorest in the world.

48 states set records for their driest or almost driest fall this year. Only Florida and Texas had wetter than normal years but that happened because of the uncontrolled intense rainfall from very big storms like Helene and Milton. There were other episodes of intense rain from unnamed storms. The extra rain has caused quite a bit of damage.

Parts of Texas are experiencing severe drought while East Texas is getting enough rainfall to classify it as a rainforest. Even with all the rain North Carolina has received 62 percent of the state is still abnormally dry. That's not drought conditions but it shows how unequal the rainfall patterns are. The weather extremes are expected to continue.

This is a geology process now being studied.

Basically, when two continental plates collide, the edges crumple up into mountains. We can see this on the map; here the Zagreb Mountains between southern Turkey and Iraq are studied. The mountains create a localised climate system, isolate biodiversity and form barriers.
This region is prone to earthquakes. A new study shows that the edges of the plates have undersea shelves that were pushed down into the mantle, subducted. The weight of these dragging down the surface, created dips where sediment from the new mountains has collected.
And the expectation, upon discovering that the Turkey side has probably let slip the weight but the Iraq side has not, would be - not in the article - that when the Iraq side does let slip the weight, it will rebound.
This will cause more earthquakes as the earth surface readjusts. May be a long time from now, we don't know.



"The geodynamic model developed in this research will benefit other fields as well.

"This research contributes to understanding how the Earth's rigid outer shell functions," explains Koshnaw.

Such research can lead to practical applications in the future by providing information for exploring natural resources such as sedimentary ore deposits and geothermal energy, and better characterization of the earthquake risks.

More information: Renas I. Koshnaw et al, The Miocene subsidence pattern of the NW Zagros foreland basin reflects the southeastward propagating tear of the Neotethys slab, Solid Earth (2024). DOI:


Provided by University of Göttingen "