VERONA- Europe's gas crisis has demonstrated the risks of moving away too fast from traditional energy sources, the head of Russian oil giant Rosneft ROSN.MM said on Thursday, adding that underinvestment could threaten the ability to meet demand.

The remarks by Igor Sechin, a close ally of Russian President Vladimir Putin, reflected the degree of resistance in Russia's powerful energy sector to embracing rapid transition to renewables - the issue at the heart of U.N.-sponsored climate talks starting in Scotland on Sunday.

Sechin told an energy conference in Verona, Italy, that global investment in oil and gas this year would be only half the level of 2014.

Renewables would not be able fully to replace traditional sources of energy even in the long term, he said, and targets on carbon neutrality could be reached without completely abandoning oil, gas and coal.

Russia is the world's fourth-biggest emitter of greenhouse gases but has said it aims to be carbon-neutral by 2060 - a target that Britain, as host of the COP26 climate summit, has urged it to bring forward by 10 years. It faces a huge challenge in reducing the dependence of its economy on hydrocarbons.

Putin's decision not to attend the talks in person has been viewed as a blow to hopes of a breakthrough agreement on action to curb climate change. 

Sechin said the gas crisis in Europe, which is facing soaring natural gas prices amid low stockpiles and higher energy demand in other parts of the world, had highighted the importance of commodity inventories.

"The current gas crisis confirms a message ... about the fragility of energy market balances and risks related to the acceleration of the energy transition and discouragement of traditional energy," he told the Eurasian Economic Forum in Verona.

Sechin also said the spike in gas prices could lead to overheating crude oil markets. Citing analysts from Citi and Goldman Sachs, he said it could trigger additional oil demand of up to 1 million barrels per day.

(Reporting by Oksana Kobzeva Writing by Vladimir Soldatkin Editing by Mark Trevelyan and David Goodman ) ((vladimir.soldatkin@reuters.com;