The growth of wildfires in the West could double the amount of sediment moving through the region’s rivers, U.S. Geological researchers found in a new study. Increased sediments can affect both water quality and the amount of water available for communities.
The USGS scientists analyzed a collection of climate, fire and erosion models for 471 large watersheds throughout the western U.S. They found that by 2050, the amount of sediment in more than one-third of watersheds could at least double. In nearly nine-tenths of the watersheds, sedimentation is projected to increase by more than 10 percent.
Without expensive measures, some strands will vanish by 2100
Scientists are warily watching the impacts of rising sea levels along the world’s coastlines, where a high percentage of the global population lives and works. In some areas — especially narrow strands are pinned between the open ocean and coastal mountains, beaches may vanish by 2100 as higher waves and bigger storm surges wash away the precious sand.
Some of the biggest waves on record took a toll on beaches
The 2015-16 El Niño may have been a bust as far as precipitation in California, but it still ended up as one of the strongest episodes of the last 145 years, according to U.S. Geological Survey scientists who studied erosion along the West Coast.
They found that, on average, erosion was 76 percent above normal, with most beaches in California eroded beyond historical extremes. If, as some research suggests, El Niños become stronger in a warming climate, then the West Coast, with its 25 million inhabitants, will become increasingly vulnerable to coastal hazards.
The study covered seasonal changes at 29 beaches from Washington to Southern California. They used 3-D maps and aerial lidar imaging, GPS topographic surveys, and direct measurements of sand levels, combined with wave and water level data to measure the changes.
Winter beach erosion or the removal and loss of sand from the beach is a normal seasonal process, but the extent of erosion can be more severe during El Niño events than in other years.
FRISCO — airborne dust, blown off dry ground, is a significant source of atmospheric carbon, according to Australian researchers, who recently set out to try and calculate how that source figures into the global carbon cycle.
Subject to intensifying droughts in some parts of the world, top soil is increasingly being blown away as dust in the wind, changing the amount and location of soil carbon. Some carbon falls back to the ground while some leaves Australia or ends up in the ocean.
Dust also plays a more direct role in regional climate. One recent study led by scientists from the University of Wisconsin-Madison and NOAA suggested that a warming in the tropical North Atlantic was largely due to reductions in airborne dust and volcanic emissions during the past 30 years.