Global warming is the long-term rise in the average temperature of the Earth’s climate system. It is a major aspect of current climate change, and has been demonstrated by direct temperature measurement and by measurements of various effects of the warming.The term commonly refers to the mainly human-caused increase in global surface temperature and its projected continuation.Human influence has been the dominant cause of the observed warming since the mid-20th century. The largest human influence has been the discharge of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. (more…)
Tag Archives: rising sea level
Millions of people across the world live or depend on deltas for their livelihoods.
Formed at the lowest part of a river where its water flow slows and spreads into the sea, deltas are sediment-rich, biodiverse areas, a valuable source of seafood, fertile ground for agriculture, and host to ports important for transportation.
At least half of the deltas around the world are so-called “wave dominated deltas” – open to the sea and under the impact of wave erosion. And many more deltas will come under wave dominance as dammed rivers carry less and less sediment. In a warming climate, sea levels are rising and storms are increasing in frequency and severity, posing threats to these deltas and the people and habitats dependent on them. (more…)
Oceanography graduate student lands scholarship supporting wetland research
Growing up along Lake Pontchartrain in New Orleans, Brandon Boyd spent a lot of time hunting for waterfowl and fishing for speckled trout in marshes and swamps. There, wetlands are a way of life.
“Ever since I was in high school, I knew I really wanted to do something to help protect wetlands,” said Boyd, a graduate student in oceanography in the School of Marine Science and Policy within the University of Delaware’s College of Earth, Ocean, and Environment. (more…)
Changes in the speed that ice travels in more than 200 outlet glaciers indicates that Greenland’s contribution to rising sea level in the 21st century might be significantly less than the upper limits some scientists thought possible, a new study shows.
“So far, on average we’re seeing about a 30 percent speedup in 10 years,” said Twila Moon, a University of Washington doctoral student in Earth and space sciences and lead author of a paper documenting the observations published May 4 in Science. (more…)
USGS scientists and academic colleagues investigated how California’s interconnected San Francisco Bay and Sacramento-San Joaquin Delta (the Bay-Delta system) is expected to change from 2010 to 2099 in response to both fast and moderate climate warming scenarios. Results indicate that this area will feel impacts of global climate change in the next century with shifts in its biological communities, rising sea level, and modified water supplies.
“The protection of California’s Bay-Delta system will continue to be a top priority for maintaining the state’s agricultural economy, water security to tens of millions of users, and essential habitat to a valuable ecosystem,” said USGS Director Marcia McNutt. “This new USGS research complements ongoing initiatives to conserve the Bay-Delta by providing sound scientific understanding for managing this valuable system such that it continues to provide the services we need in the face of climate uncertainty.” (more…)
WASHINGTON — The West Coast of North America has caught a break that has left sea level in the eastern North Pacific Ocean steady during the last few decades, but there is evidence that a change in wind patterns may be occurring that could cause coastal sea-level rise to accelerate beginning this decade.
That is the conclusion of a new study that says that conditions dominated by cold surface waters along the West Coast could soon flip to an opposite state.
“There are indications that this is what might be happening right now,” says Peter Bromirski, a researcher at Scripps Institution of Oceanography, UC San Diego, and lead author of a study now in press in the Journal of Geophysical Research–Oceans, a journal of the American Geophysical Union. (more…)