2020 Ties for the Hottest Year on Record

Credit: NASA/GISS

According to multiple sources – which includes NASA, the NOAA, the Berkeley Earth research group, and the Met Office Hadley Centre (UK) – global temperatures over the past few years have been some of the hottest on record. This is the direct result of anthropogenic factors like overpopulation, urbanization, deforestation, and increased greenhouse gas emissions (like carbon dioxide and methane).

According to a recent press release from NASA, in terms of global temperatures, 2020 was the hottest year on record – effectively tying it with 2016 (the previous record-holder). The release includes a dramatic video that illustrates average temperature increases since 1880 and the ecological crises that have taken place just this past year. This is yet another warning of how human agency is impacting the very systems we depend upon for our continued survival.

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Tree Rings Reveal 1,000 Years of Solar Activity

Solar activity over the last 1000 years (blue, with error interval in white), sunspot records (red curve) going back less than 400 years. The background shows a typical eleven-?year cycle of the sun. CREDIT ETH Zürich

The Sun has a lot of rhythm and goes through different cycles of activity. The most well-known cycle might be the Schwabe cycle, which has an 11-year cadence. But what about cycles with much longer time scales? How can scientists understand them?

As it turns out, the Sun has left some hidden clues in tree rings.

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Mars has Been Through Many Ice Ages in the Last Billion Years

Deuteronilus Mensae (DM)has many rough surface features. The Mars Reconnaissance Orbiter has shown that many areas in DM are sub-surface glaciers covered by a thin layer of debris. Image: NASA/JPL/University of Arizona

Like Earth, Mars has experienced periods of extreme glaciation or ice sheet coverage, which are known as ice ages. As these ice ages come and go, glaciers expand and contract along the planet’s surface, grinding huge boulders down to smaller rocks. By examining the size of boulders and rocks at specific locations on Mars, we should be able to understand the history of the Martian ice ages.

A new study did just that.

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Scientists Think They Know What Caused the Deadliest Mass Extinction in the History of the Earth

This illustration shows the percentage of marine animals that went extinct during Earth's worst extinction at the end of the Permian era by latitude, from the model (black line) and from the fossil record (blue dots).A greater percentage of marine animals survived in the tropics than at the poles. The color of the water shows the temperature change, with red being most severe warming and yellow less warming. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide. The images below the line represent some of the 96 percent of marine species that died during the event. [Includes fossil drawings by Ernst Haeckel/Wikimedia; Blue crab photo by Wendy Kaveney/Flickr; Atlantic cod photo by Hans-Petter Fjeld/Wikimedia; Chambered nautilus photo by John White/CalPhotos.]Justin Penn and Curtis Deutsch/University of Washington
This illustration shows the percentage of marine animals that went extinct during Earth's worst extinction at the end of the Permian era by latitude, from the model (black line) and from the fossil record (blue dots).A greater percentage of marine animals survived in the tropics than at the poles. The color of the water shows the temperature change, with red being most severe warming and yellow less warming. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide. The images below the line represent some of the 96 percent of marine species that died during the event. [Includes fossil drawings by Ernst Haeckel/Wikimedia; Blue crab photo by Wendy Kaveney/Flickr; Atlantic cod photo by Hans-Petter Fjeld/Wikimedia; Chambered nautilus photo by John White/CalPhotos.]Justin Penn and Curtis Deutsch/University of Washington

Humanity can have a love/hate relationship with itself, but there’s no denying that we’re the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as we. Several times, life had to drag itself back from near annihilation.

The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252 million years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct.

What happened?

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Pluto has Snowcapped Mountains, But Why?

On the left, the region of "Cthulhu" near the equator of Pluto and on the right, the Alps on Earth. Two identical landscapes, created by very different processes. Image Credit: © NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute © Thomas Pesquet / ESA

We can thank NASA’s New Horizons spacecraft for opening our eyes up to Pluto’s complexity. On July 14th, 2015, the spacecraft came within 12,500 km (7,800 mi) of the dwarf planet. During the flyby, New Horizons was able to characterize Pluto’s atmosphere and its surface.

Among the things New Horizons saw was a region of snowcapped mountains.

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Climate Change is Making the Atmosphere Worse for Astronomy

climate change and observatories
Global climate change's effects will reach right up the skies, affecting such places as the VLTI in Chile. Courtesy ESO.

Modern astronomical telescopes are extraordinarly powerful. And we keep making them more powerful. With telescopes like the Extremely Large Telescope and the Giant Magellan Telescope seeing first light in the coming years, our astronomical observing power will be greater than ever.

But a new commentary says that climate change could limit the power of our astronomical observatories.

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Did Snowball Earth Happen Because of a Sudden Drop in Sunlight?

This artist's illustration shows what an icy exo-Earth might look like. A new study says liquid water could persist under ice sheets on planets outside of their habitable zones. Image Credit: NASA

Hundreds of millions of years ago, Earth went through two episodes of severe glaciation. These two episodes—the Sturtian and the Marinoan glaciations—occured during the Earth’s Cryogenian Period. The Cryogenian lasted from about 720 million to 635 million years ago.

The phenomenon is called “Snowball Earth” and both instances of it happened in pretty quick succession. And while a planet encased in ice and snow sounds devastating, these episodes may have paved the way for the development of complex life.

The question is, what caused the Earth to freeze over like that?

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Martian Features Were Carved by Glaciers, not Flowing Rivers

Orbiters are giving us a chance to study the surface of Mars closely, and some of the features that pop to prominence are dry river channels. There are over 10,000 of them. But a new study suggests that glaciers on ancient Mars are responsible for many of them.

According to the study, those glaciers and the water flowing under them are resonsible for carving out some of those riverbeds, rather than free-flowing rivers.

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This Giant Iceberg Has Been Sailing the Southern Seas for Three Years Now

The iceberg A-68A floating in open waters about 1050 km from its birthplace. It's been floating for three years. Image Credit: contains modified Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO

An iceberg that calved off of from a larger ice formation has spent three years floating on the ocean near Antarctica. The iceberg broke off of the Larsen Ice Shelf in mid-July 2017. It’s been battered and split up into three pieces, but it’s still going.

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Even If We Cut Greenhouse Gas Emissions Tomorrow, it Would Take Decades for the Earth to Start Cooling Again

Our beautiful, precious, life-supporting Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA
Our beautiful, precious, life-supporting Earth as seen on July 6, 2015 from a distance of one million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. Credits: NASA

If—or hopefully when—we cut our Greenhouse Gas (GHG) emissions, we won’t notice much difference in the climate. The Earth’s natural systems take time to absorb carbon from the atmosphere. We may have to wait decades for the temperatures to drop.

Of course, that doesn’t mean we shouldn’t do it. It’s just that we have to temper our expectations a little.

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