Study says disastrous tipping points could be reached by 2050
Forests of the future may not be able to remove heat-trapping CO2 from the atmosphere as effectively as previously thought, scientists said in a new study that’s based on an extensive analysis of tree ring data from the past.
“We utilized a network of more than two million tree-ring observations spanning North America. Tree-rings provide a record into how trees that grow in different climates respond to changes in temperature and rainfall,” said Brian Enquist, a professor in the UA’s Department of Ecology and Evolutionary Biology and a fellow of the Aspen Center for Environmental Studies in Aspen, Colorado.
The research challenges assumptions about how forests will respond to warmer average temperatures, increased greenhouse gas emissions, and shifting rainfall patterns. It also suggests that the warming climate already is rapidly pushing many forests towards an ecological tipping point, which may be reached as early as 2050, Exposure to unprecedented temperatures hampers tree growth and makes them susceptible to other stress factors. Continue reading “Forests may not benefit from rising CO2 levels”→
New study shows soil moisture is a big factor in global warming equation
Methane won’t be the only problem as Arctic permafrost thaws in the coming decades. A new study shows that, as frozen permafrost areas warm and dry out, they will also release more CO2. The study was led by Northern Arizona University assistant research professor Christina Schädel and published in the journal Nature Climate Change.
The goal of limiting atmospheric carbon dioxide to 350 parts per million — considered the environmentally “safe” level, just moved a little farther away. Scientists tracking concentrations of the heat-trapping pollutant at a mountaintop lab in Hawaii said last week that CO2 concentrations jumped by the largest annual amount recorded since measurements began 56 years ago.
The reading comes from NOAA’s Mauna Loa Observatory, and researchers said the latest increase was the fourth year in a row that CO2 concentrations grew by more than 2 parts per million, according to a press release from NOAA.
‘If we don’t take action … coral reefs will not survive into the next century’
The most dangerous effects of global warming may still be decades away, but ocean scientists say that the buildup of carbon dioxide is already slowing down the growth of coral reefs. By simulating ocean acidification on a section of the Great Barrier Reef, the researchers showed that excess C02 in the atmosphere is affecting coral reefs.
“Our work provides the first strong evidence from experiments on a natural ecosystem that ocean acidification is already causing reefs to grow more slowly than they did 100 years ago,” said study lead author Rebecca Albright, a marine biologist in Carnegie’s Department of Global Ecology in Stanford, Calif. “Ocean acidification is already taking its toll on coral reef communities. This is no longer a fear for the future; it is the reality of today.” Continue reading “Study says ocean acidification has already slowed coral growth”→
New ice core study helps pinpoint global warming impacts
After studying a new ice core sample from McMurdo Sound, researchers say they’re a bit closer to one of the holy grails of climate science — understanding how Antarctic ice sheets will respond to increasing concentrations of atmospheric carbon dioxide.
The scientists looked at a 3,735-foot sediment core to reconstruct the Antarctic ice sheets’ history in an effort to create a climate model that mirrors conditions during the Miocene Era, when atmospheric CO2 levels were slightly higher, at 500 parts per million, than the 400 ppm level reached just last year, and global average temperatures were about 3 to 4 degrees Celsius higher than today. Continue reading “Antarctic ice sheets may be more sensitive to CO2 than we thought”→