Global CO2 emissions are scaling unprecedented highs despite some let up in growth as a result of slowing economies.

The latest annual report from the Global Carbon Project indicates that carbon dioxide emissions produced by the combustion of fossil fuels around the world hit a record high of 36 million tonnes last year as growth rates in emissions continue to remain robust.

The CSIRO’s Dr Pep Canadell, an executive director of the GCP as well as co-author of the 2014 report, said fossil fuel carbon dioxide emissions are expected to rise by 2.5 per cent this year, bringing the total volume of carbon dioxide emissions generated by all sources to 40 billion tonnes.

According to Canadell these carbon dioxide levels are “unprecedented in human history.”

While the increase in fossil fuel emissions has slowed since the start of the new decade as a result of easing growth in major economies, it still exceeds the rate of increase witnessed during the final decade of the 20th century.

“Fossil fuel emissions in the past 10 years on average grew at 2.5 per cent per year, lower than the growth rate in the 2000s (which was 3.3 per cent per year) but higher than the growth rate in the 1990s (one per cent),” said Canadell. “The declining growth rate in recent years is associated with lower GDP growth compared to the 2000s, particularly in China.”

Current emission levels are now veering towards the upper end of the scenarios used by climate scientists in their global circulation models to predict climate change outcomes.

The biggest fossil fuel emitters last year included China (responsible for 28 per cent emissions), the USA (14 per cent), the European Union (10 per cent) and India (7 per cent). China accounted for 58 per cent of the 2013 change in fossil fuel emissions, followed by the USA at 20 per cent, and India at 17 per cent.

Over the past two and a half decades, emerging economies have surpassed industrialised economies as the chief source of global fossil fuel emissions. While in 1990, 62 per cent of global emissions were produced by developed countries and 35 per cent in developing countries, last year this configuration had almost completely reversed, with developed countries accounting for 35 per cent of emissions, and developing countries 58 per cent.

Australia is making its own modest contribution to ameliorating the problem of global climate change, with the nation’s emissions level continuing to decline in 2013.

Australia’s CO2 emission levels have been on a downward trajectory  since 2009, primarily on the back of reductions in the usage of coal-fuelled power plants for energy generation purposes.

The latest round of emissions data arrives just following worldwide demonstrations for more concerted action on the part of governments to deal with the issue of climate change.

The Australia’s People Climate March was part of roughly 2,500 rallies staged around the world in the lead up to a United Nations summit on climate change in New York.

The rally saw 30,000 demonstrators march through the Melbourne CBD before converging upon the Treasury Gardens over the weekend, where they were addressed by environment advocate Professor Tim Flannery, who said urgent action on the issue was needed before it became too late.