The world is heading for an average temperature rise of nearly 4C (7F), according to analysis of national pledges from around the globe. Such a rise would bring a high risk of major extinctions, threats to food supplies and the near-total collapse of the huge Greenland ice sheet.

More than 100 heads of state agreed in Copenhagen last December to limit the rise in global temperatures to 1.5C-2C (2.7-3.6F) above the long-term average before the industrial revolution, which kickstarted a massive global increase in the greenhouse gases blamed for warming the planet and triggering climate change.

But six months on, a major international effort to monitor the emissions reductions targets of more than 60 countries, including all the major economies, the Climate Interactive Scoreboard, calculates that the world is on course for a rise of nearly double the stated goal by 2100.

Another study by Climate Analytics, at the Potsdam Institute in Germany, suggests there is “virtually no chance” world governments will keep the temperature rise to below 2C, and the rise is likely to be 3.5C (6.3F) by the end of the century.

In both analyses the current commitments suggest a much better outcome than the estimated business-as-usual temperature rise of 4.8C (8.6F), but are well above the 2C maximum the UN hoped would be agreed at the next major meeting this December in Cancún, Mexico – and even further from the 1.5C target many developing nations argue is needed to stop the worst impacts of climate change in their countries.

In its last assessment of the problem in 2007, the Intergovernmental Panel on Climate Change (IPCC) forecasts that a rise of more than 2C would lead to potential increases in food production, but an increasingly high risk of extinction for 20-30% of species, more severe droughts and floods, and a unstoppable “widespread to near total” loss of the Greenland ice sheet over very long time periods. However, at 4C it predicted global food production was “very likely” to decrease, “major extinctions around the globe”, and near-total loss of Greenland’s ice, precipitating 2-7m of sea-level rise in the long term. As temperatures rose, the severity of floods, erosion, water pollution, heatwaves, droughts and health problems such as malnutrition and diarrhoea diseases would also increase, said the IPCC.

Australia’s new prime minister, Julia Gillard. Photograph: Mick Tsikas/Reuters

 

Australia’s new prime minister, Julia Gillard, today moved to revive a stalled carbon trading scheme, pledging more consultation with industry and voters to win support for an issue that has divided the nation.

Gillard, in her first comments to the media after former prime minister Kevin Rudd stepped down earlier on Thursday, said she believed in climate change, backed renewable energy and that the nation needed a price on carbon emissions.

But she also said emissions trading laws would lead to a significant structural shift in the resources-rich nation and they needed to be explained properly to the community.

“It is as disappointing to me as it is to millions of Australians that we do not have a price on carbon,” Gillard told reporters.

“And in the future we will need one. But first we need to establish a community consensus for action.”

Australia is the world’s top coal exporter and among the highest per-capita emitters of carbon dioxide, with coal used to generate about 80% of electricity.

Gillard faces a national election within months and climate change will be a major election issue. Her comments are expected to appease disgruntled Greens voters who swept Rudd to power in 2007 on the promise of action on climate change.

“If elected as prime minister, I will re-prosecute the case for a carbon price at home and abroad,” Gillard said, although any steps to revive emissions trading laws are likely to be in 2011 after the elections expected towards the end of this year.

A Filipino boy is carried to safety through floodwaters in Manila in 2009. Extreme weather, including increased floods and droughts, could continue long after global temperatures are stabilised, UK scientists say. Photograph: Jay Directo/AFP

Global warming will continue to bring havoc to the world’s weather systems for decades after reductions are made in greenhouse gas emissions, a new study shows.

Scientists at the Met Office Hadley Centre in Exeter say climate change could bring greater disruption to the planet’s water cycle than previously thought.