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The Hudson River estuary in the United States experiences a tide from New York Harbor (river kilometer 0/river mile 0) to Troy, New York (river kilometer 244/river mile 152). In the lower 60 kilometers (37 miles) of the Hudson River, the water is…

Atmospheric ozone plays a critical role in the biosphere by absorbing harmful ultraviolet radiation in the stratosphere—the layer of the atmosphere about 10 to 50 km (6 to 30 mi) above Earth’s surface. Since the adoption of the Montreal Protocol in…

The Paris Agreement is a treaty signed by 196 member nations of the United Nations Framework Convention on Climate Change (UNFCCC) in an effort to reduce greenhouse-gas (GHG) emissions, primarily of carbon dioxide and methane, thereby limiting the…

Scientists predict that Earth’s climate will continue changing, depending in large part on the additional amount of greenhouse gases that humans emit into the atmosphere, leading to negative consequences for life on Earth. To avoid the most harmful…

Wildfires are a natural phenomenon in many ecosystems, including forests along the U.S. Pacific West Coast, as natural fires serve to rejuvenate ecological communities. However, from mid-August through mid-September 2020, forests in California,…

Microplastics are raining down on national parks and other protected areas in the western United States at the rate of about 132 pieces of microplastic per square meter every day, according to a report in the journal Science (June 2020).…

Many questions concerning the sustainable production of biofuels have emerged over recent years in terms of land and water use, pollution from fertilizer and pest-control chemicals, greenhouse-gas production, net energy production, and whether…

Obscured by a hazy atmosphere 100 times thicker than Earth's, Venus is a notoriously difficult world to study. Ground temperatures on Venus exceed 450°C (842°F)—enough to melt lead and to have quickly degraded the Soviet robotic landers last placed…

The novel coronavirus SARS-CoV-2 that emerged in central China in late 2019 and subsequently spread across the world in 2020 led to the COVID-19 pandemic. The emergence of a previously unknown pathogen—such as the novel coronavirus—that could affect…

The world’s oceans and coasts provide a natural sink for excess carbon in the atmosphere. Scientists refer to carbon that is captured and stored this way as blue carbon. Well-known blue-carbon examples include mangroves and salt marshes—wetland…

Using an artificial intelligence technique known as deep learning and high-resolution remote sensing, scientists have counted and mapped the location of trees in 11,000 satellite images covering more than 1.3 million square kilometers (500,000…

During the past decade, the automotive industry has converted more than 50 percent of its internal combustion engines from a traditional technology called port fuel injection (PFI) to a new technology called gasoline direct injection (GDI). The…

Ground-level, or tropospheric ozone (O3), is a strong oxidizing agent that reacts with living tissue. Consequently, tropospheric ozone is considered an air pollutant and a respiratory irritant at low concentrations. At higher concentrations,…

A rare and very large area of severely depleted ozone (03) opened up in the stratosphere above the Arctic Circle in March 2020. Scientists attribute this ozone hole to the persistence of a very strong polar vortex (a jet stream that circles the…

Concrete is the most widely used construction material worldwide because of its versatility, strength, and durability. Applications range from roadways and dams to furniture and tiles. With proper manufacturing, reinforcement, and engineering…

Many trees in forests worldwide rely on natural fires to create growing conditions necessary to perpetuate the ecosystem, or to stimulate germination. However, for more than 100 years, humans have been suppressing frequent natural low-intensity…

Persistent changes in the Earth's climate that have been occurring primarily as a result of human-caused greenhouse-gas emissions since the mid-twentieth century have led to significant increases in infectious diseases in wildlife, both in terms of…

Sea-level rise is caused by adding mass (water) and heat to the ocean. The Antarctic ice sheet represents a potentially large source of water. Knowing the speed and direction (velocity) at which the Antarctic ice sheet is flowing to the ocean is…

It has been a long-held belief that, as a result of hunting habits, early humans were partly or even primarily responsible for the decline and eventual extinction of most of the largest mammalian species that inhabited ancient Africa. These large…

Researchers from Rice University in Houston, Texas, United States, have found that climate change could potentially increase the size of stalled high-pressure weather systems (ridges) known as “blocking events,” according to global climate modelling…

Trees provide substantial benefits to the environment. In addition to improving air quality, reducing stormwater runoff, serving as a wildlife habitat, and sequestering carbon by absorbing carbon dioxide, trees also cool the atmosphere through shade…

Sand is mined for many applications, but the largest use by far is for fine aggregate in concrete. Smaller quantities of sand are used for fracking, water treatment (filtration), metal casting, and making glass, silicon chips, and ceramics. Concrete…

A study published in the journal Atmospheric Environment (April 2019), comparing the differences in air pollution caused by automobiles powered by internal combustion (conventional) engines versus electric vehicles (EVs) powered by batteries,…

Researchers have reached a key new milestone in the continuing search for worlds like Earth that could support life elsewhere in the universe. For the first time, water vapor has been detected in the atmosphere of an exoplanet that resides within…

Researchers surveying ice loss from 650 glaciers across a 2000-kilometer (1240-mile) west-to-east expanse of the Himalayan Mountains reported in the journal Science Advances (June 2019) significant melting caused by global climate change over the…

All freshwater comes from precipitation over land, which is distributed on Earth as blue and green water. Blue water—that is, surface and groundwater—is stored as freshwater in lakes, streams, ice, and snow, as well as below ground. Green water is…

Researchers Chi Ma of Caltech and Alan Rubin of the University of California at Los Angeles reported in the journal American Mineralogist (September 2019) the discovery in a meteorite of the first natural occurrence of the iron-carbide mineral…

Earth’s surface temperature is warming, and the Arctic region is warming even faster. Yet winters in the mid-latitudes of Asia, Europe, and the United States have been colder than average, thanks to blasts of record-breaking frigid air caused by…

After reports that June 2019 was the warmest June on record, July 2019 followed with the dubious distinction that it was the warmest month since atmospheric temperature record-keeping began in 1880, according to the U.S. National Oceanic and…

Researchers at Duke University in North Carolina (United States) have developed a test for distinguishing lead isotopes found in coal fly ash from lead isotopes found in other lead-containing sources, such as paint. Fly ash is a fine particulate…

In 1987, the Montreal Protocol, the international treaty banning chemicals that deplete the ozone layer, was adopted. Thirty years later, NASA scientists reported in the journal Geophysical Research Letters (January 2018) satellite measurements…

On August 5, 2018 at 6:46 p.m. local time, a magnitude 6.9 earthquake struck in Pulau Lombok, Indonesia. The earthquake occurred as the result of thrust faulting at a depth of 10.5 km (6.5 mi) in northern Lombok, according to the United States…

Crown-of-thorns starfish or sea stars (Acanthaster planci; order Valvatida) are predatory marine invertebrates that feed on phytoplankton found on coral. They are native inhabitants of coral reefs in both the Indian Ocean and Pacific Ocean and are…

The Mississippi River has undergone extensive river engineering for flood control, with its 3500-mile Mississippi River and Tributaries levee (artificial-embankment) system. However, researchers reported in Nature (April 2018) that disconnecting the…

The warming temperatures attributed to global climate change are making it more difficult for sea turtle populations to survive. As a result of the unusual developmental processes found in many reptiles, including some species of turtles, the sex of…

Sunscreens are polluting the ocean, and increasing evidence points toward some ultraviolet-light–absorbing chemicals found in sunscreens as being harmful to marine life—particularly corals at popular tourist destinations. While working toward…

In the fall of 2014 and early winter of 2015, an estimated 250,000 to 500,000 seabirds known as Cassin's auklets (Ptychoramphus aleuticus) died along the Pacific Coast from California to British Columbia, Canada. Researchers have now reported the…

Humans' contributions to global warming through burning fossil fuels and other actions (for example, detrimental land-use practices) have resulted in sharp increases in the levels of atmospheric carbon dioxide (CO2). These rising levels of CO2 also…

Limiting the effects of climate change to the greatest extent possible will require reducing greenhouse-gas (GHG) emissions and removing GHGs from the atmosphere. In addition, the shared goal of the countries that have entered into the Paris Climate…

By July 6, 2018, beaches on the eastern coast of St. Vincent—an island located in the southeastern Caribbean Sea (Lesser Antilles)—were covered nearly one-meter deep with rotting brown algae (seaweed), known as Sargassum, posing multiple problems…

For more than 10 years, natural-gas-fired power plants have been touted as “cleaner” electrical power generators, producing half the carbon dioxide (CO2), one-third of the nitrogen oxides (NOX), and negligible sulfur oxides (SOX) compared to…

As the global climate becomes hotter and drier, heat mitigation in urban areas through the use of cool roofs is becoming increasingly important. Cool roofs reflect more sunlight and absorb less heat than conventional roofs, according to the U.S.…

There are 27 ways a heat wave can kill you, according to a report in the American Heart Association journal Circulation: Cardiovascular Quality and Outcomes (November 2017). By 2100, at the current rate of greenhouse-gas emissions, three-quarters of…

Roman marine concrete, having lasted for nearly 2000 years, is a highly durable material. In contrast, modern marine concrete, which is made using Portland cement, may start to degrade in as few as 50 years. Researchers have now discovered why. As…

Recent excavations in Asia unearthed a pristine, three-dimensional fossil of a tiny dinosaur tail with preserved feathers and soft tissues (presumably skin). In 2016, investigators in northern Myanmar (Burma) recovered a piece of Cretaceous-era…

Global climate change affects all areas of the Earth, with some regions experiencing greater impacts than others. In particular, the Arctic treeline—that is, the southern limit of the Arctic Bioclimate Zone—is being affected to various degrees by…

Hurricane Harvey made landfall near the middle of the Texas Gulf Coast on August 25, 2017 as a Category 4 storm on the Saffir-Simpson Hurricane Wind Scale and essentially hovered over the region for seven days, unleashing heavy rain and causing…

On August 30, 2017, just as Hurricane Harvey was winding down in Texas, tropical storm Irma formed near the Cape Verde Islands located off the northwest coast of Africa and began moving west-northwest. According to the U.S. National Hurricane…

If three occurrences constitute a trend, then catastrophic storms—that is, Category 4 or 5 storms on the Saffir-Simpson Hurricane Wind Scale—are the trend for Atlantic hurricanes in 2017. One day after forming as a tropical depression, Potential…

Forests absorb and store carbon. If this ability is hampered, then levels of atmospheric carbon will increase and global temperatures will rise, leading to potentially drastic climatic changes. In particular, deforestation (the permanent elimination…