Archives quotidiennes :

unclassified

Scientists Uncover Cause of 1831 Global Cooling Event That Triggered Crop Failures, Famines

by J. Chadwick, Dec 31, 2024 in ClimateChangeDispatch

It’s been nearly 200 years since a global cold snap led to widespread crop failures and devastating famines. [emphasis, links added]

Now, a new study by scientists at the University of St Andrews finally pinpoints the cause.

The Zavaritskii volcano on the remote, uninhabited Russian island of Simushir, part of the Kuril Islands, erupted in 1831, the experts reveal.

The dramatic event injected volcanic ash into the atmosphere, blocking enough sunlight to induce a brief global cooling period.

The resulting change in weather included reduced rainfall from Africa and India to Japan, causing major famine due to poor crop yields.

‘While scientists have long known that a really big eruption went off in 1831, the source has remained a mystery,’ lead study author Dr Will Hutchison told MailOnline.

Dr Hutchison and his team were able to date and match the ice core deposits to Zavaritskii volcano on the remote, uninhabited island of Simushir. Source: University of St Andrews
…
better to know...?

Trump Wants Greenland and the Panama Canal. It’s About Climate.

by L. Friedman, Dec 31, 2024 in TheNewYorkTimes

To imagine the kind of future a hotter, dryer climate may bring, and the geopolitical challenges it will create, look no farther than two parts of the world that Donald Trump wants America to control: Greenland and the Panama Canal.

The president-elect in recent days has insisted that both places are critical to United States national security. He’s called to reclaim control the Panama Canal from Panama and acquire Greenland from Denmark, both sovereign territories with their own governments.

They have something else in common as well: Both are significantly affected by climate change in ways that present looming challenges to global shipping and trade.

Because of warming temperatures, an estimated 11,000 square miles of Greenland’s ice sheets and glaciers have melted over the past three decades, an area roughly equivalent to the size of Massachusetts. That has huge implications for the entire world. If the ice melts completely, Greenland could cause sea levels to rise as much as 23 feet, according to NASA.

…

unclassified

Scientists Report A ‘Striking Global Greening Trend’ Over The Last 42 Years

by K. Richard, Dec 30, 2024 in NoTricksZone

The greening of the Earth’s vegetated areas is “attributed to CO2 fertilization, climate change, and land use changes.”

New remote sensing research (Gutiérrez-Hernández and García, 2025) uses robust statistical methods to eliminate false positives and spurious correlations in establishing vegetation trends in the satellite era.

The scientists find 38% of the Earth’s land surface has undergone statistically significant greening or browning trends over the last 42 years (1982-2023). Conventional methods (i.e., Mann-Kendall test) that had previously found 51% of the Earth’s surface experienced statistically significant vegetation trends in the satellite era may overlook crucial factors that produce less accurate, inflated results.

With this new analytical method, the True Significant Trends (TCT) test, the authors have robustly determined there has been a “striking global greening trend” attributed to CO2 fertilization and climate change.

“Applying a new proposed workflow methodology (True Significant Trends, TST) we reveal a striking global greening trend, with a significant portion of the Earth’s terrestrial land surface showing increases in vegetation cover over the past four decades, particularly in Eurasia.”

Specifically, 76.1% to 85.4% of statistically significant vegetation trends indicate greening, whereas browning trends account for 14.7 to 23.9%

“Among these significant trends identified using the TST workflow, 76.07% indicated greening, while 23.93% indicated browning. Notably, considering areas (pixels) with NDVI values above 0.15, greening accounted for 85.43% of the significant trends, with browning making up the remaining 14.57%. These findings strongly validate the ongoing global greening of vegetation.”

…