Evidence of Impending Tipping Point for Earth

A group of scientists from around the world is warning that population growth, widespread destruction of natural ecosystems, and climate change may be driving Earth toward an irreversible change in the biosphere, a planet-wide tipping point that would have destructive consequences absent adequate preparation and mitigation.

“It really will be a new world, biologically, at that point,” warns Anthony Barnosky, professor of integrative biology at the University of California, Berkeley, and lead author of a review paper appearing in the June 7 issue of the journal Nature. “The data suggests that there will be a reduction in biodiversity and severe impacts on much of what we depend on to sustain our quality of life, including, for example, fisheries, agriculture, forest products and clean water. This could happen within just a few generations.”

Read more here.

Thirsty, anyone? This amazing illustration from the U.S. Geological Survey shows just how little water on earth there actually is.

This picture shows the size of a sphere that would contain all of Earth’s water in comparison to the size of the Earth. The blue sphere sitting on the United States, reaching from about Salt Lake City, Utah to Topeka, Kansas, has a diameter of about 860 miles (about 1,385 kilometers) , with a volume of about 332,500,000 cubic miles (1,386,000,000 cubic kilometers). The sphere includes all the water in the oceans, seas, ice caps, lakes and rivers as well as groundwater, atmospheric water, and even the water in you, your dog, and your tomato plant.

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Stop-and-go plate tectonics

Plate tectonics might have gotten a fitful start on the early Earth. Today, the process of Earth’s crustal movement called plate tectonics dictates nearly everything about the planet’s appearance, from the sites and heights of the mightiest mountain ranges to the depths of the oceans’ trenches. But geologists have long argued about when thin, rigid crustal plates first formed on the young planet and began jostling against one another. Now, two researchers propose that plate tectonics started and stopped over and over, billions of years ago, before running continuously.

In the graphic above, a simulation of plate tectonics today (left) shows a crustal slab (green) plunging more than 400 kilometers into Earth’s mantle. Billions of years ago (right), when the mantle was 200 degrees Celsius hotter, the slab would have barely penetrated the depths before breaking off and foundering. Geologists propose this difference led to intermittent plate tectonic activity early in Earth’s history.

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Where the Life is Very Old.

To get a sense of how life on Earth used to be, visit Shark Bay, Australia, one of the very few places on the planet where you can see living stromatolites. These structures are rounded towers of sediment built over thousands of years by cyanobacteria, or blue-green algae. The stromatolites at Shark Bay are a few thousand years old, but they’re nearly identical to the life that thrived on Earth 3.5 billion years ago, when oxygen made up just 1 percent of the atmosphere. Though they’re found in a few extra-salty bodies of water around the world, stromatolites are at their most diverse and most abundant at Shark Bay.

Asteroid Impact Craters on Earth as Seen From Space

In this photo: The Shoemaker crater in Western Australia, formerly known as the Teague crater, was renamed in honor of the planetary geologist Eugene Shoemaker for whom the Comet Shoemaker-Levy 9 is also named. The age of the crater unclear, but it could be 1.7 billion years old, which makes it the oldest known impact in Australia. The brightly colored splotches are seasonal salt-water lakes. This image was taken by the Landsat 7 satellite. (Image: NASA/USGS, 2000.)

See more photos here.

There is an asteroid called 2011 AG5, and if it follows the orbit scientists have plotted for it so far, there is a small, small chance that it could hit Earth in February 2040.  Read the full article here.

Sun setting over the Pacific Ocean, as seen from ISS.

mineralia:

Elbaite from Afghanistan