A new study finds that human activity globally has caused ecosystems to lose about 15 percent of their species abundance on average—crossing what the researchers say is a safe boundary. Other ecologists, however, take issue with what they call an "arbitrary" threshold. Washington Post
The world's third-largest emitter has pledged to cut carbon 35 percent and boost clean energy 40 percent by 2030. But Prakash Javadekar, the outgoing climate minister, says India could try harder and achieve those goals even sooner. He encouraged other countries to follow suit. The Guardian
Temperatures in many Alaskan cities this week rocketed into the high 80s. Deadhorse, near the Arctic Ocean, hit 85, the highest temperature ever recorded in the area. Meteorologists are expecting a massive heat wave to hit much of the Lower 48 next week, too. ThinkProgress
Unless people do more they will end up wearing the pollution on their faces in 10 years’ time.
—Dr. Mervyn Patterson, a cosmetic doctor in the United Kingdom, discusses how air pollution accelerates wrinkles and other types of skin aging in urban areas.
Following a summit in the Solomon Islands this week, the leaders of 14 countries are now considering a Pacific climate treaty that would ban expansion of coal mines and embrace the 1.5-degree target laid out in Paris in December. The Guardian
The extraordinary years have become the normal years.
—NASA scientist Walt Meier discusses the extreme changes seen in the Arctic thus far in 2016.
On her first full day in office, the United Kingdom's new prime minister made the "deeply worrying" decision to abolish the Department for Energy and Climate Change and transfer its responsibilities to the Department for Business, Energy & Industrial Strategy. Not cool, Britannia! The Independent
Save the Arctic
Urge Congress to give Alaska's spectacular Arctic National Wildlife Refuge the protection it deserves.
The cubs were discovered in the Santa Susana Mountains, just north of the city. The birth announcement is great news for the area's cougar population, which—penned in by freeways and development— has extremely low genetic diversity. National Geographic
And the changing patterns could boost warming.
This story originally appeared on Climate Central.
The warming of the planet over the past few decades has shifted a key band of clouds poleward and increased the heights of clouds tops, exacerbating the earth’s rising temperature, a new study released Monday suggests.
The reaction of clouds to a warming atmosphere has been one of the major sources of uncertainty in estimating exactly how much the world will heat up from the accumulation of greenhouse gases, as some changes would enhance warming, while others would counteract it.
The study, detailed Monday in the journal Nature, overcomes problems with the satellite record and shows that observations support projections from climate models. But the work is only a first step in understanding the relationship between climate change and clouds, with many uncertainties still to untangle, scientists not involved with the research said.
Cloud Changes
While clouds are a key component of the climate system, helping to regulate the planet’s temperature, their small scale makes them difficult to accurately represent in climate models.
Using satellite observations to look for trends is also problematic because they come solely from weather satellites, which aren’t geared to producing consistent, long-term records. In addition, some satellites have been replaced over time, have changed orbit, or seen degradation of their sensors, introducing false trends.
Joel Norris of the Scripps Institution of Oceanography and his colleagues had previously figured out a way to remove those artifacts in the satellite data to reveal actual trends since the early 1980s. They focused on looking for those patterns that showed up in different climate models and that our physical understanding of the atmosphere supports.
Namely, the observations showed that the main area of storm tracks in the middle latitudes of both hemispheres shifted poleward, expanding the area of dryness in the subtropics, and that the height of the highest cloud tops had increased.
Such changes reinforce global warming: There is less solar radiation at the high latitudes near the poles, so as clouds shift that way, they have less radiation to reflect back to space. High cloud tops mean that more of the radiation that is absorbed and re-emitted by the earth’s surface is trapped by the clouds (akin to the greenhouse effect).
More Work to Do
To investigate whether these changes in cloud patterns could be chalked up to the natural variation of the climate system, Norris and his team compared climate models that included external influences like rising greenhouse gases and volcanic eruptions with those that did not. The former showed the same trends as the observations, while the latter didn’t. “The pattern of cloud change we see is the pattern associated with global warming,” Norris said.
Kate Marvel, a climate researcher with NASA’s Goddard Institute for Space Studies, agreed but cautioned that the cloud shifts are also consistent with what would be expected during recovery from major volcano eruptions, of which there were two at the beginning of the study period.
“More work is needed to tease out the relative roles of greenhouse gas emissions and volcanic eruptions,” she said in an e-mail.
Norris plans to tackle this question in future work, as well estimate exactly how much clouds have changed.
The study also doesn’t deal with some of the cloud changes that are expected to be most important, namely those to low clouds in the subtropics, Bjorn Stevens, of the Max-Planck-Institute for Meteorology—and the lead author of the chapter on clouds and aerosols in the most recent Intergovernmental Panel on Climate Change report—said in an e-mail.
Monday’s study is a step toward better understanding how clouds will change along with the climate and lays bare the limitations of the satellite record and the need for better long-term observations, said Stevens, who was not involved with the research. “This study reminds us how poorly prepared we are for detecting signals that might portend more extreme (both large and small) climate changes than are presently anticipated,” he said.
Reporting was contributed by John Upton.
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