‘We need to manage the risks of warming with the knowledge we have.’
FRISCO — Australian scientists say that, even though they’ve managed to narrow the range of projected global warming, some uncertainties will always remain. The findings underscore the need to cut greenhouse gas emissions, said University of Melbourne professor David Karoly.
“Our results reconfirm the need for urgent and substantial reductions in greenhouse gas emissions if the world is to avoid exceeding the global warming target of 2 degrees needed to minimize dangerous climate change,” Karoly said.
Concentration will wane from seasonal high point, but long-term trend is up
By Summit Voice
FRISCO — Climate scientists have been closely tracking atmospheric carbon dioxide levels for a long time, but this week, the colorless, odorless gas made big headlines.
An atmospheric observatory on Mauna Loa for the first time measured daily concentrations of CO2 at slightly above 400 parts per million, a dubious milestone which, better than any other number, captures the extent to which we are changing the world. Continue reading “Climate: Atmospheric CO2 reaches 400 ppm”→
SUMMIT COUNTY — Large parts of the northern hemisphere could see a 20 to 30 percent increase in extreme precipitation events by the end of the century. Extra moisture due to a warmer atmosphere dominates all other factors, leading to notable increases in the most intense precipitation rates, according to a new NOAA-led study.
The study shows a 20-30 percent expected increase in the maximum precipitation possible over large portions of the Northern Hemisphere by the end of the 21st century if greenhouse gases continue to rise at a high emissions rate.
SUMMIT COUNTY — Climate scientists have long been warning that a meltdown of Arctic permafrost will trigger a spike in greenhouse gas emissions as long-frozen organic soils give up their carbon to the atmosphere. What’s not yet clear is how fast and how much of the permafrost will melt, but a new study helps identify a temperature threshold that could lead to widespread melting.
A team led by Oxford University scientists studied stalactites and stalagmites in caves along Siberia’s permafrost frontier, where the ground begins to be permanently frozen in a layer tens to hundreds of meters thick.
The stalactites and stalagmites only grow when liquid rainwater and snow melt drips into the caves. The formations record 500,000 years of changing permafrost conditions, including warmer climate periods. After studying the paleoclimate clues in the caves, the researchers concluded that another 1.5 degrees of warming would be enough to cause substantial thawing of permafrost far north from its present-day southern limit. Continue reading “What’s the climate tipping point for permafrost?”→
Activists say deep greenhouse gas cuts needed to avoid climate disaster
By Summit Voice
FRISCO — A recent federal draft report on climate change has spurred renewed calls for deep cuts in greenhouse gas emissions to avert the most serious impacts from rising global temperatures.
The report, which is in a public comment phase, concludes that global warming is already affecting the U.S. Warmer temperatures will endanger food supplies, increase the risk of flooding and powerful hurricanes, and warm the country by as much as 10 degrees by 2100.
SUMMIT COUNTY — Delaying meaningful action on climate change is tempting, but will likely prove to be very costly in the long run, an international group of researchers warned this week in an article in Nature Climate Change.
The easiest path is to reaching the targeted 2-degree cap in global temperatire increases would be to significantly cut greenhouse gas emissions. If that doesn’t happen by 2020, the goal is still attainable, but at a much greater cost, with much higher climate risks and and under exceedingly optimistic assumptions about future technologies.
The researchers say this is what needs to happen sooner, rather than later:
Nuclear power would need to remain on the table as a mitigation option, or people would need to quickly adopt advanced technology strategies, including electric vehicles and highly efficient energy end-use technologies such as appliances, buildings, and transportation. Meanwhile, coal-fired power plants would need to be rapidly shut down and replaced with other energy sources.