Carbon dioxide emissions, the greenhouse gas that has been most strongly implicated in global warming, will reach a record high of 40 billion tons.

The new report has been released by the Global Carbon Project just prior to the New York Climate Summit, where advocates will seek new action on climate change. Unfortunately, the protesters in New York City are complaining in the wrong place; American greenhouse gas emissions have plummeted back to early 1990s levels and coal emissions are are at early 1980s levels. The 2.5 percent emissions increases have instead been due to countries that are exempt from climate treaties, such as world leader China and India and Mexico. 

The latest update predicts that total future CO2 emissions cannot exceed 1,200 billion tons if we are to keep the average global warming under 2°C. At the current rate of CO2 emissions, this 1,200 billion ton CO2 'quota' would be used up in around 30 years. This means that there is just one generation before the safeguards to a 2 degree limit would be exceeded.

The international team says that in order to avoid this scenario, more than half of all remaining fossil fuel reserves can't be used.

Prof Corinne Le Quéré, Director of the Tyndall Centre at University of East Anglia, said, "The human influence on climate change is clear. We need substantial and sustained reductions in CO2 emissions from burning fossil fuels if we are to limit global climate change. We are nowhere near the commitments necessary to stay below 2°C of climate change, a level that will be already challenging to manage for most countries around the world, even for rich nations.

"Politicians meeting in New York need to think very carefully about their diminishing choices exposed by climate science."

The annual Global Carbon Budget, published today, includes a projection for 2014, as well as figures for 2013 by country and per capita. 

Lead author of the Nature Geoscience paper, Prof Pierre Friedlingstein, from the University of Exeter said, "The time for a quiet evolution in our attitudes towards climate change is now over. Delaying action is not an option - we need to act together, and act quickly, if we are to stand a chance of avoiding climate change not long into the future, but within many of our own lifetimes.

"We have already used two-thirds of the total amount of carbon we can burn, in order to keep warming below the crucial 2°C level. If we carry on at the current rate we will reach our limit in as little as 30 years' time - and that is without any continued growth in emission levels. The implication of no immediate action is worryingly clear – either we take a collective responsibility to make a difference, and soon, or it will be too late."

Key facts and figures:

• CO2 emissions from burning fossil fuel are projected to rise by 2.5 per cent in 2014 - 65 per cent above 1990 levels, the reference year for the Kyoto Protocol

• China, the USA, the EU and India are the largest emitters – together accounting for 58 per cent of emissions.

• China's CO2 emissions grew by 4.2 per cent in 2013, the USA's grew by 2.9 per cent, and India's emissions grew by 5.1 per cent.

• The EU has decreased its emissions by 1.8 per cent, though it continues to export a third of its emissions to China and other producers through imported goods and services.

• China's CO2 emissions per person overtook emissions in the EU for the first time in 2013. China's emissions are now larger than the US and EU combined. 16 per cent of China's emissions are for goods and services which are exported elsewhere.

• Emissions in the UK decreased by 2.6 per cent in 2013 caused by a decline in the use of coal and gas. However the UK exports a third of its emissions by consuming goods and services which are produced elsewhere.

• CO2 emissions are caused primarily by burning fossil fuels, as well as by cement production and deforestation. Deforestation accounts for 8 per cent of CO2 emissions.

• Historical and future CO2 emissions must remain below a total 3,200 billion tonnes to be in with a 66 per cent chance of keeping climate change below 2°C. But two thirds (2,000 billion tonnes) of this quota have already been used.

• If global emissions continue at their current rate, the remaining 1,200 billion tonnes will be used up in around 30 years – one generation.

• Global emissions must reduce by more than 5 per cent each year over several decades to keep climate change below 2°C.

• This emission quota implies that over half of proven fossil reserves might have to remain unused in the ground, unless new technologies to store carbon in the ground are developed and deployed in large quantities.