Flowing Martian Water was Protected by Sheets of Carbon Dioxide

An artistic interpretation of an ice-covered river sourced from meltwater beneath Mars’ south polar cap. Image Credit: Peter Buhler/PSI.

Mars’ ancient climate is one of our Solar System’s most perplexing mysteries. The planet was once wet and warm; now it’s dry and cold. Whatever befell the planet, it didn’t happen all at once.

New research shows that on ancient cold Mars, sheets of frozen carbon dioxide allowed rivers to flow and a sea the size of the Mediterranean to exist.

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Satellites are Tracking the Ongoing Sea Level Rise Swamping Pacific Island Nations

Low-lying Pacific Ocean nations such as Kiribati are preparing for a future where sea level rise could swamp their coastlines. Credit: NASA Earth Observatory.
Low-lying Pacific Ocean nations such as Kiribati are preparing for a future where sea level rise could swamp their coastlines. Credit: NASA Earth Observatory.

The small island nations of the South Pacific are facing the harsh reality of sea level rise. Within 50 years they will be swamped by rising seas linked to climate change. That’s part of a stark forecast from a sea level change science team at NASA and leading universities.

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From Frozen to Sweltering: Earth’s Climate Over the Last 485 Million Years

New research shows the global mean surface temperature across the last 485 million years. The gray shading corresponds to different confidence levels, and the black line shows the average. The colored bands along the top reflect the climate state, with cooler colors indicating icehouse (coolhouse and coldhouse) climates, warmer colors indicating greenhouse (warmhouse and hothouse) climates, and the gray representing a transitional state. Image Credit: Judd et al. 2024.

Earth’s last half-billion years were action-packed. During that time, the climate underwent many changes. There have been changes in ocean levels and ice sheets, changes in the atmosphere’s composition, changes in ocean chemistry, and ongoing biological evolution punctuated with extinction events.

A record of Earth’s temperature over the last 485 million years is helping scientists understand how it all played out and illustrating what could happen if we continue to enrich the atmosphere with carbon.

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Advanced Civilizations Will Overheat Their Planets Within 1,000 Years

Global temperature increases over the past thirty years, visualized. Credit: NOAA/NCEI

Earth’s average global temperatures have been steadily increasing since the Industrial Revolution. According to the National Oceanic and Atmospheric Agency (NOAA), Earth has been heating up at a rate of 0.06 °C (0.11 °F) per decade since 1850 – or about 1.11 °C (2 °F) in total. Since 1982, the average annual increase has been 0.20 °C (0.36 °F) per decade, more than three times as fast. What’s more, this trend is projected to increase by between 1.5 and 2 °C (2.7 to 3.6 °F) by mid-century, possibly more! This is a direct consequence of burning fossil fuels, which has increased exponentially since the mid-19th century.

Depending on the extent of temperature increases, the impact on Earth’s habitability could be catastrophic. In a recent study, a team of scientists examined how temperature increases are a long-term issue facing advanced civilizations and not just a matter of fossil fuel consumption. As they argue, rising planetary temperatures could be an inevitable result of the exponential growth of energy consumption. Their findings could have serious implications for astrobiology and the Search for Extraterrestrial Intelligence (SETI).

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Can Geoengineering Protect Earth’s Icesheets?

This image shows the change in Greenland ice thickness in just one year, 2015. Almost ten years have passed, Greenland is still melting, and our GHG emissions are still rising. Is it time to use geoengineering to stall the melting? Image Credit: ESA/Planetary Visions.

It’s time to take a thorough, more serious look at using geoengineering to protect the planet’s icesheets, according to a group of scientists who have released a new report examining the issue. Glacial geoengineering is an emerging field of study that holds some hope for Earth’s diminishing glaciers and ice sheets.

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Was Earth’s Climate Affected by Interstellar Clouds?

About two million years ago, the Solar System may have passed through a dense cloud of hydrogen and radioactive material. It compressed the heliosphere, the protective cocoon the Sun provides for Earth and the other planets. It's shown here as the dark gray bubble over the backdrop of interstellar space. This could have exposed Earth to high levels of radiation and influenced the climate, and possible human evolution. Photo courtesy of Opher, et al., Nature Astronomy

Scientists scour the Earth and the sky for clues to our planet’s climate history. Powerful and sustained volcanic eruptions can alter the climate for long periods of time, and the Sun’s output can shift Earth’s climate over millions of years.

But what about interstellar hydrogen clouds? Can these regions of gas and dust change Earth’s climate when the planet encounters them?

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Another Giant Antarctic Iceberg Breaks Free

Modified data obtained by the ESA's Copernicus Sentinel-1 satellite. Credit: ESA/USGS

On May 20th, 2024, an iceberg measuring 380 square kilometers (~147 mi2) broke off the Brunt Ice Shelf in Antarctica. This event (A-83) is this region’s third significant iceberg calving in the past four years. The first came In 2021, when A-74 broke off the ice sheet, while an even larger berg named A-81 followed in 2023. The separation of this iceberg was captured by two Earth Observation satellites – the ESA’s Copernicus Sentinel-1 and NASA’s Landsat 8 satellites – which provided radar imaging and thermal data, respectively.

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How Animal Movements Help Us Study the Planet

This map shows how elephants moved across Kruger National Park in South Africa over one year. Image Credit: Thaker, M., et al. (2019)

Scientists have been underutilizing a key resource we can use to help us understand Earth: animals. Our fellow Earthlings have a much different, and usually much more direct, relationship with the Earth. They move around the planet in ways and to places we don’t.

What can their movements tell us?

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NASA and Boeing Release New Rendering of their X-66 Sustainable Experimental Airliner

Artist’s concept of the X-66 aircraft that Boeing will produce through NASA’s Sustainable Flight Demonstrator project. Credit: NASA

Climate change is arguably the single greatest threat facing the world today. According to the Sixth Assessment Report (AR6) by the UN Intergovernmental Panel on Climate Change (IPCC), average global temperatures are set to increase between 1.5 and 2 °C (2.7 to 3.6 °F) by mid-century. To restrict global temperatures to an increase of 1.5 C and avoid the worst-case scenarios, the nations of the world need to achieve net zero emissions by then. Otherwise, things will get a lot worse before they get better, assuming they ever do.

This means transitioning to cleaner methods in terms of energy, transportation, and aviation. To meet our climate commitments, the aviation industry is developing technology to significantly reduce air travel’s carbon footprint. To help meet this goal, NASA and Boeing have come together to create the X-66 Sustainable Experimental Airliner, the first experimental plane specifically focused on helping the U.S. achieve net-zero aviation. Last week, NASA released a new rendering of the concept, giving the public an updated look at the future of air travel.

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Satellite Measurements Show That Global Carbon Emissions are Still Rising

Tracking carbon emissions and sinks to determine Earth's annual Global Carbon Budget. Credit: NASA GEOS

According to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), human activities have significantly impacted the planet. As global greenhouse gas emissions (mainly carbon dioxide) have continued to increase, so too have global temperatures – with severe ecological consequences. Between 2011 and 2020, global surface temperatures rose by an estimated 1.07 °C (2.01 °F) above the average in 1850–1900. At this rate, temperatures could further increase by 1.5 to 2 °C (2.7 to 3.6 °F) in the coming decades, depending on whether we can achieve net zero by 2050.

Unfortunately, the data for the past year is not encouraging. According to the 2023 Global Carbon Budget (GCB), an annual assessment of Earth’s carbon cycle, emissions in 2023 continued to rise by 1.1 percent compared to the previous year. This placed the total fossil fuel emissions from anthropogenic sources at 36.8 billion metric tons (over 40 US tons) of carbon dioxide, with an additional 4.1 billion metric tons (4.5 US tons) added by deforestation, extreme wildfires, and other sources. This trend indicates we are moving away from our goals and that things will get worse before they get better!

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