Global shares plunge and oil surges to almost $140 a barrel, as US and Europe consider a ban on Russian energy exports

• Global shares fell Monday, with heavy losses in Europe in light of a possible Western ban on Russian oil.
• Crude surged to almost $140 a barrel overnight, as other key Russian exports like nickel and palladium also jumped.

Global shares tumbled on Monday, after Western leaders said they might consider a ban on Russia's energy exports, which sent oil surging to its highest in almost 14 years and ignited fears of widespread economic turmoil.

Brent crude roared towards $140 a barrel for the first time since July 2008 when Asian markets opened overnight. Russia is the world's third-largest exporter of crude, and one of the largest exporters of refined fuels and natural gas.

Secretary of State Antony Blinken told NBC's "Meet the Press" on Sunday that the US was in discussion with European allies about a ban of Russian oil exports.

US stock futures sagged, with those on the S&P 500 falling 1.4%, those on the Dow Jones shedding 1.2%, and those on the Nasdaq 100 falling 1.7% in early European trading.

"It's hard to see much in the way of significant upside for stock markets now against a backdrop of continued escalation, and raise the question of how much further Putin is prepared to go to achieve his goals," CMC Markets chief strategist Michael Hewson said.

"It is these concerns over slowing growth across the world, as well as surging commodity price inflation that is also acting as a headwind for stock markets more broadly and is the biggest challenge facing central banks all over the world, starting with the European Central Bank later this week," he said.

Brent crude was last up 7.7% at $127.25 a barrel, having surged overnight by as much as 10% to $139.13 a barrel, the highest since July 2008. Meanwhile, WTI futures were up 6.8% at $124.33 a barrel.

In Europe, the Stoxx 600 fell 2.8% in early trade, while Frankfurt's DAX plunged by 4%. Germany is more exposed to any fallout from Russia than many other European countries. It relies on Russia for 70% of its natural gas, for example.

The MSCI All-World index was last down almost 1% on the day.

As the conflict in Ukraine has intensified, so has the global backlash for Russia. Major corporations have fled the country and commodity traders have already shunned the country's key exports for fear of being stuck with cargoes of sanctioned or unmovable material.

It's not just the price of oil that has surged. Nickel, palladium, aluminum, coal, wheat and others have ripped to multi-year or record highs, while its ruble currency has hit record lows.

"Commodity prices continue to rise generally, and talk of cutting off Russian oil supplies would likely mean further rises, boosting global inflation yet further while also putting pressure on consumer spending," strategists at broker IG said in a note.

Nickel, used in steel, rose almost 25% on the day on the London Metal Exchange to $37,540 a ton, while palladium, which is used in autocatalysts, rose almost 9% to trade around $3,258 an ounce. Wheat futures rallied 7% to $1,294 a bushel.

NATO foreign ministers meet later on Monday to discuss what further measures the organization can take given Russia's escalation of violence.

Read more: UBS upgrades its outlook for silver, which it believes will offer value to investors in the face of the current volatility — and lays out whether the surge in the broader commodities sector has room to run as war in Ukraine moves into a second week