GAINESVILLE, Fla. — Florida has the world’s worst invasive amphibian and reptile problem, and a new 20-year study led by a University of Florida researcher verifies the pet trade as the No. 1 cause of the species’ introductions.
From 1863 through 2010, 137 non-native amphibian and reptile species were introduced to Florida, with about 25 percent of those traced to one animal importer. The findings appear online today in Zootaxa. (more…)
Geophysical Sciences Professor David Archer polled the 200 students in one of his Global Warming classes about whether they believed that humans have had an impact on climate. Approximately 90 percent of the students responded “yes,” reflecting the lessons of climate simulations that Archer had shared earlier with the students.
Those computer simulations are able to reproduce the trend toward rising temperatures, but only when they include data on rising carbon dioxide concentrations in the atmosphere. Simulations that omit the CO2 data do not accurately reproduce the changes. Archer says the link helps reveal carbon dioxide emissions as “the smoking gun” behind global warming and climate change. (more…)
“Less than we thought,” researchers say in a new study providing insights into the distribution of biodiversity across the globe.
The temperate forests of Canada or Northern Europe may have much more in common with the tropical rainforests of Southeast Asia or South America than previously believed, according to a research group including a University of Arizona ecologist.
The assertion, published as the cover article in the journal Science, is focused on the concept of “beta-diversity” – a measure of the change in species composition between two sites, such as neighboring patches of forest. High beta-diversity means that two given sites have few species in common. (more…)
*Computer simulations of global climate lead to new conclusions*
Earth’s deep oceans may absorb enough heat at times to flatten the rate of global warming for periods of as long as a decade–even in the midst of longer-term warming. This according to a new analysis led by scientists at the National Center for Atmospheric Research (NCAR).
The study, based on computer simulations of global climate, points to ocean layers deeper than 1,000 feet as the main location of the “missing heat” during periods such as the past decade when global air temperatures showed little trend. (more…)
The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder’s National Snow and Ice Data Center.
The Arctic sea ice extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year’s minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September — an area larger than Texas and California combined. (more…)
*A new framework for evaluating human influences on wildfires is developed*
Fires have continuously occurred on Earth for at least the last 400 million years. But since the 1970s, the frequency of wildfires has increased at least four-fold, and the total size of burn areas has increased at least six-fold in the western United States alone. Steadily rising, the U.S.’s bill for fighting wildfires now totals $1.5 billion per year.
How much of the increases in the frequency and size of fires are due to human activities? No one knows for sure. But a paper in this week’s issue of the Journal of Biogeography puts the role of fire in natural ecosystems into context and provides support for efforts to plan for future risks from wildfires. (more…)
Washington, DC — Scientists have long debated about the impact on global climate of water evaporated from vegetation. New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere. These findings, published September 14 in Environmental Research Letters, have major implications for land-use decision making.
Evaporative cooling is the process by which a local area is cooled by the energy used in the evaporation process, energy that would have otherwise heated the area’s surface. It is well known that the paving over of urban areas and the clearing of forests can contribute to local warming by decreasing local evaporative cooling, but it was not understood whether this decreased evaporation would also contribute to global warming (more…)
EAST LANSING, Mich. — When countries try to work together to limit the effects of climate change, the fear of being the only nation reducing greenhouse gas emissions – while the others enjoy the benefits with no sacrifice – can bring cooperation to a grinding halt.(more…)
