Human activities are releasing carbon dioxide faster than ever, while the natural processes that normally slow its build up in the atmosphere appear to be weakening, according to a new report. The report states that “together, these effects characterize a carbon cycle that is generating stronger-than-expected climate forcing sooner than expected.”

Between 2000 to 2006, human activities such as burning fossil fuels, manufacturing cement, and tropical deforestation contributed an average of 4.1 billion metric tons of carbon to the atmosphere each year, yielding an annual growth rate for atmospheric carbon dioxide of 1.93 parts per million (ppm). “This is the highest since the beginning of continuous monitoring in 1959,” states the report.

A study published by Nutrition Journal says they can demonstrate substantial advances in long term weight management and blood glucose levels as a result of personalizing patients' diets based on their genetic information (nutrigenetics).  They found significant improvement in long term (more than 300 days) weight management for individuals whose nutrient requirements were tailored to individual variations in the genes known to affect nutrient metabolism and transport.

The Autism Consortium has completed the first genome scan for Autism Spectrum Disorders (ASD) through its Autism Gene Discovery Project and has released the reference data set to a database that autism researchers around the world can use. The scan was conducted using new, high resolution technology developed by Affymetrix on genetic data from more than 3,000 children with ASD and their families.

People with medium levels of HIV in their blood are likely to contribute most to the spread of the virus, according to new research published today in the journal Proceedings of the National Academy of Sciences.

The study, by researchers from Imperial College London, looked at several groups of HIV-positive people in Europe, the USA and sub-Saharan Africa. It found that those with a high viral load are the most infectious group, but have only limited time to infect others, because they generally progress to AIDS quite quickly.

Viral load - a count of how many viral particles are in a person’s blood – varies hugely between individuals. The higher the viral load, the more infectious a person is but the shorter their life expectancy.

There has been a decline in the efficiency of natural land and ocean sinks which soak up carbon dioxide (CO2) emitted to the atmosphere by human activities, according to findings published this week in the Proceedings of the National Academy of Sciences of the US (PNAS).

The swift increase in atmospheric CO2 is due to faster economic growth coupled with a halt in carbon intensity reductions, in addition to natural sinks removing a smaller proportion of emissions from the air. Carbon intensity is the amount of carbon emitted to produce one dollar of global wealth.

The study’s lead author, Dr Pep Canadell, executive director of the Global Carbon Project, explained “Fifty years ago, for every tonne of CO2 emitted, 600kg were removed by natural sinks.

“Being a coral reef scientist these days can be depressing. So many reefs around the world have collapsed before our eyes in the past few years,” says Professor Terry Hughes, Director of the ARC’s Centre of Excellence for Coral Reef Studies. “But we’ve got to get past the gloom-and-doom, and use the best science to find practical ways to protect reefs from global warming.”

The world has a narrow window of opportunity to save coral reefs from the destruction caused by extreme climate change, according to a unanimous statement issued today by leading Australian scientists (see communiqué, above). The call for action is the outcome of a National Forum on Coral Reef Futures, held at the Australian Academy of Science, in Canberra.