Energy firm's analysis finds switch to other fuels like shale gas will do little to cut carbon emissions

Global greenhouse gas emissions are set to rise by nearly a third in the next two decades, putting hopes of curtailing dangerous climate change beyond reach, a new report by BP has found.

The drastic rise in emissions, despite international efforts to cut carbon, will come despite the predicted enormous growth in the use of shale gas, according to the oil and gas giant.

Shale gas – previously inaccessible because the exploitation of these resources requires technology only recently perfected – will account for a rising proportion of the growth in energy in the years to 2035, but its use will not cause a decline in greenhouse gases.

The finding deals a blow to proponents of shale gas, who have argued that its use will cut emissions. Burning gas produces much less CO2 than burning coal, but the effect of a huge rise in shale gas exploration will not ameliorate the increases in emissions that scientists say will take the world to dangerous climate change.

Proponents of the fuel have argued that shale gas can counteract dependence on coal. But while shale gas use has increased dramatically, particularly in the US, where it brought down gas prices from $12 (£7) to below $3 (£1.80) at one stage, global emissions have continued to rise as the coal that would otherwise have been used has been exported elsewhere.

Christof Ruehl, BP chief economist, said that fuel switching had little impact on overall emissions. Coal use globally had risen to record levels, even as shale gas had risen.

In the UK, shale gas has received a boost from David Cameron, who vowed to go all out for shale by offering taxpayer-funded giveaways to companies. But the news that such a move will not cut overall emissions takes away a key plank in the arguments put forward by shale companies.

BP in its global energy outlook said gas would take a 27% share of global energy consumption by 2035, with a similar share for coal, oil, and an amalgamated low-carbon sector including nuclear, hydro, wind and sun.

BP predicts that global emissions will rise 29% by 2035. The Intergovernmental Panel on Climate Change says that emissions must peak by 2020 to give the world a chance to avoid a further two degrees of warming, beyond which the effects of climate change become catastrophic and irreversible.

Tony Bosworth, Friends of the Earth energy campaigner, said: "The case for shale gas is crumbling. Experts say it won't lead to cheaper fuel bills, and now BP says it won't cut carbon emissions either.

"Follow the PM's logic and we'd be punching thousands of holes in our countryside only to further add to climate change and continue with sky-high bills.

"Instead of going all out for shale, the prime minister should focus on the real answers to the energy challenges we face: energy efficiency and renewable power."

Meanwhile, analysts at the City firm Brewin Dolphin also poured scorn on Cameron and George Osborne for over-hyping the potential impact of shale in Britain. "We believe the shale industry is unlikely to produce commercial volumes of gas until the end of this decade and that it is unlikely to have a meaningful impact on gas prices," said a report drawn up by Elaine Coverley, head of equity research, and Iain Armstrong, oil and gas equity analyst at the investment house.

"This is due to two reasons; first, commercially available volumes are likely to be significantly lower in the UK than in the US, and second, if UK shale is successful, exploration companies could export the gas to achieve higher prices," they argue.

Their comments came as a new opinion poll for the Institution of Mechanical Engineers (IME) found that 47% of people would be unhappy for a gas well site using fracking to open within 10 miles of their home, compared with just 14% who said they would be happy.

The findings come just days after the prime minister announced that councils that back fracking will get to keep more money from the business tax revenues once production at a well is under way.

The biggest concerns for the people polled included fears of damage to the local environment, the associated noise and disruption, fears over the chemicals used and health risks, as well as fears that drinking water might be contaminated.

Tim Fox, head of energy and environment at the IME, said: "These poll results suggest that simply offering money to local councils and communities is not enough to convince the public about the benefits of fracking for gas and that much more work needs to be done to engage with citizens on this potential activity.

"Building trust between government, industry and communities is essential if we wish to make use of this technique in shale rocks under the UK."

The Guardian carried out the first UK nationwide poll on shale last summer and found people split down the middle, 40% in favour of shale drilling in their area, 40% against, with 20% unsure. The IME poll suggests attitudes to shale are hardening rather than softening.