Piecing Together Australia's Climate Change Picture

Article excerpt

CSIRO researchers have been playing a leading role in tracking the emerging signals of climate change, advancing understanding about how the phenomenon will impact the Asia-Pacific region.

CSIRO Marine and Atmospheric Research scientists contributed to recent studies identifying an acceleration of carbon dioxide emissions beyond current estimates; a weakening of the Southern Ocean's capacity to absorb carbon dioxide; temperature changes in the Indian Ocean affecting ocean currents and mainland rainfall; and the crucial role played by tropical forests in reducing greenhouse gases.

A team led by Dr Mike Raupach from CSIRO Marine and Atmospheric Research has reported that the average growth rate of carbon dioxide emissions globally has accelerated at a greater rate than previously thought, increasing from 1.1 per cent per year in the 1990s to a 3 per cent annual increase in the 2000s.

Dr Raupach's team of carbon-cycle experts, emissions experts and economists was brought together through the Global Carbon Project-an international framework for climate change research.

The team reported recently that, over the last 25 years, the average growth rate of Australian emissions was roughly twice the growth rate for the world, twice the growth rate for the USA and Japan, and five times the growth rate for Europe.

Dr Raupach also found that Australia's carbon intensity of energy (amount of carbon burned as fossil fuel per unit of energy) is 20 per cent higher than the world average, and 25-30 per cent higher than the USA, Europe and Japan.

'In the last few years, the global usage of fossil fuels has actually become less efficient,' says Dr Raupach.

'Our results add to previous findings that carbon dioxide concentrations, global temperatures and sea-level rise are all near the high end of IPCC (Intergovernmental Panel on Climate Change) projections.'

CSIRO participated in an international research team that has presented evidence of a progressive weakening of the Southern Ocean's capacity to act as a carbon dioxide sink.

According to Dr Paul Fraser from CSIRO Marine and Atmospheric Research, the work has shown that the Southern Ocean is becoming less efficient at absorbing carbon dioxide due to an increase in wind strength over the ocean. …