Atmospheric



By Agus Santoso, Senior Research Associate at UNSW Australia.

It looks like it’s all over bar the shouting for the chance of this year bringing on a “super” El Niño. Or is it?

Carbon tetrachloride (CCl4) was once used in dry cleaning and as a fire-extinguishing agent but once it was found to be a cause of ozone depleted, it was regulated in 1987 under the Montreal Protocol along with other chlorofluorocarbons. Parties to the Montreal Protocol have reported zero new CCl4 emissions since, though worldwide emissions of CCl4 still average 39 kilotons per year, about 30 percent of emissions prior to the treaty going into effect.


Changes in the Asian monsoon have affected emissions of methane from the Tibetan Plateau over the last 6,000 years, finds a new paper.

The concentration of methane in the atmosphere has more than doubled over the past century, though it is very short lived compared to carbon dioxide and hasn't been considered much of a factor in climate change. Factors in methane levels include leaks from gas wells, increased rice cultivation and ruminant animals in the dairy and meat industry. It could also be caused partly by climate change feedbacks on natural processes, but that remains the subject of intense investigation. 

A recent study analyzed concentrations of African dust transported to South America and finds large seasonal peaks in winter and spring, which provides new insight into the overall human health and air quality impacts of African dust, including climate change-induced human health effects.

Researchers analyzed the dust concentrations in aerosol samples from two locations, French Guiana's capital city Cayenne and the Caribbean islands of Guadeloupe, to understand the amount, source regions, and seasonal patterns of airborne dust that travels across the North Atlantic Ocean.


Global warming is currently taking a break. Global temperatures seemed to have risen drastically into the late 1990s but the global average temperature has risen only slightly since 1998 – surprising, considering scientific climate models predicted considerable warming due to rising greenhouse gas emissions. In 2006, former U.S. Vice-President Al Gore said by 2016 it would be too late if we did not stop CO2 immediately.

Climate skeptics use this contradiction to question climate change as well as the validity of climate models. Meanwhile, the majority of climate researchers continued to emphasize that a short-term 'warming hiatus' can largely be explained on the basis of current scientific understanding and did not contradict longer term warming.


American CO2 emissions have plummeted thanks to natural gas and energy emissions from coal have not been this low since the early 1980s, but a decades long war against energy science meant nuclear power - a truly viable emissions-free source - was scuttled and that meant more coal plants starting in the early 1990s, which meant more CO2.


Transport accounts for an up to 30% of CO2 emissions in the EU, with estimates claiming that emissions from that sector rose 36% between 1990 and 2007. 

A new analysis conducted by Lund University and the University of Surrey takes on the widely-held view that new technologies, such as biofuel and improved aircraft design, will result in carbon reduction targets being met. 


Dusty air blowing across the Pacific from Asia and Africa is playing a critical role in precipitation patterns throughout the drought-stricken western U.S.

The exact chemical make-up of that dust, including microbes found in it, is the key to how much rain and snow falls from clouds throughout the region and knowing this could help better predict rain events, as well as explain how air pollution from a variety of sources influences regional climate in general.


Weather extremes have been linked to a recently discovered mechanism: the trapping of giant waves in the atmosphere.

A new data analysis now shows that such wave-trapping events are indeed on the rise.  One reason could be changes in circulation patterns in the atmosphere. By analyzing large sets of global weather data, the researchers found an intriguing connection.  


Rossby Waves: meandering airstreams


The Intergovernmental Panel on Climate Change (IPCC), a United Nations geographically-chosen group of climate researchers, is the most high-profile science body in the world. Publicly they state that short-term weather events not be linked to climate change, since if every heat wave is called proof of global warming, every snowstorm will be called proof against it.

Despite UN cautions, numerous papers still link short-term weather events to climate change. In Climate Dynamics,
Florida State University geography professor