It said pollution "continued to track the average of the most carbon-intensive family of scenarios" put forward by the UN's Intergovernmental Panel on Climate Change (IPCC).
Professor Corinne Le Quéré, the lead author of the study from the British Antarctic Survey, said: "The projections of climate that have been made before are always based on scenarios of climate change, so they tell that if the emissions are such and such you get 2C, if they are such and such you get six or seven.
"What our study is doing is identifying that the trend in the CO2 emissions, particularly from fossil fuels in the past decades, is so large it is at the higher end of the emissions scenario and this is why I am saying that we are on the scenario for a 6C warming," she told Al Jazeera.
Under the IPCC's most extreme scenario, the Earth's surface will warm by around four degrees Celsius by 2100 compared with 2000 - a rise consistent with a wipeout of species, widespread hunger, flooding, drought and homelessness.
The new report highlighted the situation in emerging economies, such as China and India, where emissions have more than doubled since 1990 and now emit more greenhouse gases than developed countries.
"The emerging economies in developing countries are getting out of poverty and that is associated with more CO2 emissions," Le Quéré said.
"We have also analysed why that is the case and of their growth one quarter of it is due to the production and international trade of goods that are consumed in the West.
"There is an issue of equity. The actual emissions that have been put in the atmosphere, 80 per cent of them are from rich countries, but if other countries are allowed to emit as much CO2 as the rich countries have in the past we are going to go to this six degrees warming.
Sarah Clifton of Friends of the Earth told Al Jazeera: "This is yet more evidence, if any more was needed, of a strong and fair deal at Copenhagen in December in order to help us reduce emissions and avoid catastrophic climate change.
"Politicians are hiding behind each other, no one wants to step up and take the action, and what we actually need to see is political leadership by the rich countries. We need emission reductions, commitments from the the rich countries of at least 40 per cent by 2020.
"We also need to see the rich countries committing the finance to developing countries so they can grow cleanly, tackle emissions and adapt to the challenges of climate change."
Le Quéré's team of researchers also warned that the world's natural carbon absorbing "sinks" - the oceans and forests - were failing to keep up with the amount of emissions being pumped into the atmosphere.
In the last 50 years, the proportion of CO2 pumped into the atmosphere that remains there has risen from about 40 to 45 per cent, fuelling the greenhouse effect.
"This is of concern, as it indicates the vulnerability of the sinks to increasing emissions and climate change, making natural sinks less efficient 'cleaners' of human carbon pollution," Pep Canadell, GCP Executive Director, said.
C02 emissions from the burning of fossil fuels increased by 29 per cent from 2000 to 2008, and 41 per cent between 1990 and 2008, the GCP said.
It added that despite the global economic downturn, emissions increased by two per cent during 2008.