Tag Archives: climate

Airborne Technology Helps Manage Elephants

By Guest PostAugust 26, 2012Environment, Nature3 d mapping, africa, airborne technology, atmosphere, cao, carbon, carnegie, climate, danie pienaar, ecology letters, ecosystem, elephant, elephant conservation, elephant trap, Environment, greg asner, habitat, herbivore, kruger national park, lidar, management practice, savanna, sequester, shaun levick, South Africa, terrain condition, toppling tree, treefall, vegetation

Washington, D.C. – For years, scientists have debated how big a role elephants play in toppling trees in South African savannas. Tree loss is a natural process, but it is increasing in some regions, with cascading effects on the habitat for many other species. Using high resolution 3-D mapping, Carnegie scientists have for the first time quantitatively determined tree losses across savannas of Kruger National Park. They found that elephants are the primary agents—their browsing habits knock trees over at a rate averaging 6 times higher than in areas inaccessible to them. The research also found that elephants prefer toppling trees in the 16-to-30 foot (5-8 m) range, with annual losses of up to 20% in these height classes. The findings, published in Ecology Letters, bolster our understanding of elephant conservation needs and their impacts, and the results could help to improve savanna management practices.

“Previous field studies gave us important clues that elephants are a key driver of tree losses, but our airborne 3-D mapping approach was the only way to fully understand the impacts of elephants across a wide range of environmental conditions found in savannas,” commented lead author Greg Asner of Carnegie’s Department of Global Ecology. “Our maps show that elephants clearly toppled medium-sized trees, creating an “elephant trap” for the vegetation. These elephant-driven tree losses have a ripple effect across the ecosystem, including how much carbon is sequestered from the atmosphere.” (more…)

Climate and Drought Lessons from Ancient Egypt

By Guest PostAugust 16, 2012Culture, Environment, Scienceachilles heel, ancient egypt, babylonian, benjamin horton, charcoal, christopher bernhardt, climate, climate change, drought, egypt, egyptian history, evolution of societies, geological record, giza, great pyramid, human history, jean daniel stanley, marcia mcnutt, microscopic charcoal, middle east, modern iraq, nile basin vegetation, nile delta, nile delta sediment, old kingdom, pollen, pyramid building time, spinx, syrian kingdom, ugarit kingdom, university of pennsylvania, uruk kingdom

Using Fossil Pollen to Augment Historical Records

Ancient pollen and charcoal preserved in deeply buried sediments in Egypt’s Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200 years ago associated with the demise of Egypt’s Old Kingdom, the era known as the pyramid-building time.

“Humans have a long history of having to deal with climate change,” said Christopher Bernhardt, a researcher with the U.S. Geological Survey. “Along with other research, this study geologically reveals that the evolution of societies is sometimes tied to climate variability at all scales – whether decadal or millennial.” (more…)

Impulsive Micromanagers Help Plants to Adapt, Survive

By Guest PostAugust 16, 2012Scienceatmospheric co2, climate, concentration, drought, environmental change, environmental factor, global change, jay lennon, jen lau, plant, precipitation pattern, soil microbe, warmer temperature

EAST LANSING, Mich. — Soil microbes are impulsive. So much so that they help plants face the challenges of a rapidly changing climate.

Jen Lau and Jay Lennon, Michigan State University biologists, studied how plants and microbes work together to help plants survive the effects of global changes, such as increased atmospheric CO2 concentrations, warmer temperatures and altered precipitation patterns. The results, appearing in the current issue of the Proceedings of the National Academy of Sciences, showed that microbes in the ground not only interact with plants, but they also prompt them to respond to environmental changes.

“We found that these changes in the plants happen primarily because of what global changes do to the belowground microbes rather than the plant itself,” said Lau, who works at MSU’s Kellogg Biological Station. “Drought stress affects microbes, and they, in turn, drive plants to flower earlier and help plants grow and reproduce when faced with drought.” (more…)

Scientists Discover New Trigger for Immense North Atlantic Ocean Spring Plankton Bloom

By Guest PostJuly 7, 2012Environmentadam huxtable, amala mahadevan, atlantic ocean, biological pump, bjarni saemundsson, carbon dioxide, climate, climate on earth, CO2, craig lee, diatoms, don rice, eddies, emily kallin, eric d asaro, fossil fuel, global carbon cycle, holiday fireworks, mary jane perry, michael ohmart, microscopic plants, modulate, north atlantic bloom, not sunlight, nsf, ocean physics, oceanic cycling, oxygen, photosynthesis, physical biological model, phytoplankton, research vessel, silica, sun, surface warming, university of maine, university of washington, us beachgoers, whirlpools, whoi, zooplankton

Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles

On this July 4^th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.

In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.

What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)

NASA Scientist: Climate Just One Factor in Wildfires

By Guest PostJuly 4, 2012Environment2002 hayman fire, ash creek fire, bill patzert, climate, climate change, colorado, factor, fiery summer, forests, grasslands, horse creek fire, jpl climatologist, la niña, los angeles county, misr, nasa scientist, new mexico, southeastern montana, southern california, united states, us wildfire season, wildfire

It’s shaping up to be a fiery summer across the United States. According to the National Interagency Fire Center, as of July 3, 45 large active wildfires are currently burning in 15 states. Combined, these fires have scorched nearly three-quarters of a million acres. Since January 1, wildfires have burned nearly 2.2 million acres across the country, including devastating blazes in Colorado and New Mexico. We asked JPL Climatologist Bill Patzert to discuss the recent wildfire outbreak and whether climate change is playing a role.

Q: The U.S. wildfire season is off to an active start. What factors have contributed to the recent rash of blazes?

Patzert: Across the West, out-of-control wildfires this summer have left a heartbreaking path of destruction. The primary condition that triggered these fires was an unusually dry and warm La Nina winter and spring. These conditions primed the Western U.S. for an incendiary summer. The arrival of a persistent, scorching high-pressure system over the Western and Central U.S. just exacerbated already dangerous conditions, which reached a tipping point when strong, gusty winds sent these fires rampaging across the landscape. From New Mexico to Colorado and many other states, out-of-control wildfires are still burning through forests, grasslands and destroying neighborhoods. (more…)

Hacking Code of Leaf Vein Architecture Solves Mysteries, Allows Predictions of Past Climate

By Guest PostMay 27, 2012Environment, Natureancient greeks, carbon dioxide, christine scoffoni, climate, conifers, cycads, Environment, ferns, flowering plants, fossil record, global ecology, hacking code, images of leaves, lawren sack, leaf fossils, leaf sizes, leaf vein architecture, leaf vein systems, mathematical equation, mathematical linkages, michael rawls, past climate, photosynthesis, photosynthetic rate, plants, prediction, respiration, scaling patterns, superhighways, theophrastus of lesbos, tropical forest tree, ucla life scientists, vein network, water transport, xylem pipes

UCLA life scientists have discovered new laws that determine the construction of leaf vein systems as leaves grow and evolve. These easy-to-apply mathematical rules can now be used to better predict the climates of the past using the fossil record.

The research, published May 15 in the journal Nature Communications, has a range of fundamental implications for global ecology and allows researchers to estimate original leaf sizes from just a fragment of a leaf. This will improve scientists’ prediction and interpretation of climate in the deep past from leaf fossils.

Leaf veins are of tremendous importance in a plant’s life, providing the nutrients and water that leaves need to conduct photosynthesis and supporting them in capturing sunlight. Leaf size is also of great importance for plants’ adaptation to their environment, with smaller leaves being found in drier, sunnier places. (more…)

Study Finds Surprising Arctic Methane Emission Source

By Guest PostApril 22, 2012Environmentarctic methane, arctic ocean, arctic region, Arctic sea ice, arctic tundra soil, beaufort seas, carbon monoxide, chukchi, climate, concentration, earth system, eric kort, geologic reservoir, global warming, greenhouse gas, harvard university, hippo, jet propulsion laboratory, marine sediment, methane, NASA, ozone, reservoir, water vapor

The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth’s climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming. Now a multi-institutional study by Eric Kort of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself. (more…)

Thawing Permafrost 50 Million Years Ago Led To Warm Global Events, Says New Study

By Guest PostApril 7, 2012EnvironmentAntarctica, arctic permafrost, carbon, climate, climatic threshold, CO2, earth, eccentric orbits, ecosystem, Environment, floor sediment, fossil fuel, frozen-soil, greenhouse gas levels, italy, kevin schaefer, methane gas, ocean, orbit, organic matter, paleocene eocene, permafrost, permafrost thaw, petm, rob deconto, soil, source, thermal maximum, university of urbino

A new study led by the University of Massachusetts Amherst and involving the University of Colorado Boulder proposes a simple new mechanism to explain the source of carbon that fed a series of extreme warming events on Earth about 50 million years ago called the Paleocene-Eocene Thermal Maximum, or PETM, as well as a sequence of similar, smaller warming events afterward.

“The standard hypothesis has been that the source of carbon was in the ocean in the form of frozen methane gas in ocean-floor sediments,” said lead study author Rob DeConto of the University of Massachusetts Amherst. “We are instead ascribing the carbon source to the continents in polar latitudes where permafrost can store massive amounts of carbon that can be released as CO2 when the permafrost thaws.” (more…)