Tiempo Climate Newswatch

The Northern Hemisphere warmth of the most recent ten years is greater than at any time over the past 1300 years according to the latest estimate of long-term temperature trends derived from indirect climate data. The evidence used includes information from marine and lake sediment cores, ice cores, coral cores and tree rings. "We looked at a much expanded database and our methods are more sophisticated than those used previously," said Michael Mann of Penn State University in the United States.

The researchers assessed the use of tree-ring data in the analysis, an aspect of earlier studies that had drawn criticism. "Ten years ago, we could not simply eliminate all the tree-ring data from our network because we did not have enough other proxy climate records to piece together a reliable global record," said Mann. "With the considerably expanded networks of data now available, we can indeed obtain a reliable long-term record without using tree rings." Tree-ring data can be used, with care, to extend the record back a further 400 years. The recent warmth is without precedent even over this longer period.

Ross Garnaut, government adviser, has called for a focus on biosequestration to reduce the impact of the new Australian emissions trading regime. "We are, of the OECD countries, probably the country in the world with the largest area of woodlands and forest per capita and this vast area is going to provide very large potential for biosequestration of many kinds," he said. He considers that Northern Australia's savannahs have great potential to store carbon.

The drought that, for many years, has been affecting Australia's main food-growing region, the Murray-Darling river system, has intensified. Eighty per cent of the region's eucalyptus trees are dead or stressed. "It seems to me from what we've seen to date, there's no indication that it's going to end in the immediate future," said Wendy Craik of the Murray-Darling Basin Commission. Over the past two years, water inflows have been at an all-time low. "What we really need to make some inroads in the situation is a big wet, and what our weather models aren't showing is a strong likelihood of a big wet over the next few months," said Neil Plummer of the National Climate Centre.

The price of carbon may rise as a result of the downward adjustment of the number of certified emissions reductions (CERs) likely to be issued over coming years. The revised estimate is the result of bottlenecks in the approval process for Clean Development Mechanism (CDM) projects. The Carbon Market and Investors Association recently said that delays were resulting in "losses with regard to both opportunity costs and real costs to CDM developers."

Henrik Hasselknippe at Point Carbon commented that the United Nations Environment Programme had been trying to reduce the bottlenecks through the appointment of more staff, but an increase in the number of applications and tightening of the approval process has meant continuing delays. He is confident, though, that the situation will improve. "There are always areas that can be improved," he said, "but we shouldn't forget that this market is still very young and it is getting better all the time."