Children born today will see the world committed to dangerous and irreversible levels of climate change by their young adulthood at current rates, as the world poured a record amount of greenhouse gases into the atmosphere this year.

Annual carbon dioxide emissions showed a strong rise of 2.5% on 2013 levels, putting the total emitted this year on track for 40bn tonnes. That means the global ‘carbon budget’, calculated as the total governments can afford to emit without pushing temperatures higher than 2C above pre-industrial levels, is likely to be used up within just one generation, or in thirty years from now.

Scientists think climate change is likely to have catastrophic and irreversible effects, including rising sea levels, polar melting, droughts, floods and increasingly extreme weather, if temperatures rise more than 2C. They have calculated that this threshold is likely to be breached if global emissions top 1,200 billion tonnes, giving a “carbon budget” to stick to in order to avoid dangerous warming.

Dave Reay, professor of carbon management at the University of Edinburgh, said: “If this were a bank statement it would say our credit is running out. We’ve already burned through two-thirds of our global carbon allowance and avoiding dangerous climate change now requires some very difficult choices. Not least of these is how a shrinking global carbon allowance can be shared equitably between more than 7bn people and where the differences between rich and poor are so immense.”

The study, by the Global Carbon Project, also found that China’s per capita emissions had surpassed those of Europe for the first time, between 2013 and 2014.

It comes ahead of a climate summit on Tuesday in New York, at which the UN secretary-general Ban Ki-moon will bring together heads of state and government from more than 120 countries to discuss climate change, and encourage them to make commitments on emissions reductions in the run-up to a crunch meeting in Paris late next year, at which a new global agreement on emissions is expected to be signed.

Emissions for 2014, according to the research, are set to rise to 40bn tonnes. That compares with emissions of 32bn tonnes in 2010, showing how fast the output is rising.

The rising trend has continued despite increasingly alarming warnings from scientists over the future of the climate, and commitments by developed countries to cut their carbon and from major developing economies to curb their emissions growth. There was a brief blip in global emissions growth at the time of the banking crisis, but this “breathing space” was quickly overtaken by an expansion in fossil fuel demand.

The growth in emissions also comes despite the much-vaunted contribution of shale gas to the world’s energy mix. Some supporters of the technology claim it will bring down emissions, because gas produces less carbon than coal when burned. But studies have shown that although this may dent the rate at which emissions rise, it is unlikely by itself to produce an absolute fall in carbon output levels. US emissions rose by nearly 3% in 2013, after falling in the previous five years, despite its shale gas boom.

As much as half of the world’s proven reserves of all fossil fuels will need to be left in the ground if we are to avoid the worst effects of climate change, the research suggested.

The study, published as a paper in the peer-review journal Nature Geoscience, called “Persistent growth of CO2 emissions and implications for reaching climate targets”, is a collaboration of research groups around the world.

The overtaking of Europe by China in terms of emissions per person - about 7.2 tonnes of carbon dioxide per person per year, the study found, compared with Europe’s 6.8 tonnes per person - is politically significant.

China has long argued that it should take on far less of the burden of emissions cuts than developed nations, because it bore less responsibility for the stock of carbon poured into the atmosphere since the industrial revolution, and because its emissions per person were lower. China’s president, Xi Jinping, has indicated he will not attend Ban Ki-moon’s meeting next week, as has Narendra Modi, India’s prime minister.

The change in the make-up of emissions contributions will be a difficult topic at next year’s Paris conference on the climate.

China and India were the only two nations to hold out almost to the last minute in the talks in 2011 at which governments set the deadline of the Paris talks for the sign-off of a new pact on the climate, to replace current national emissions targets that expire in 2020. India’s per capita emissions are still low, at 1.9 tonnes, but the country’s total emissions are likely to overtake those of the EU by 2019.