A group of current and former employees of Shell is publicly challenging the oil giant’s climate strategy at its shareholder meeting in London on Tuesday, warning that the company’s continued focus on oil and liquefied natural gas could expose both the business and investors to major long-term risks.The group, made up of five current and 19 former employees with an average of 20 years of experience at Shell, submitted a resolution questioning how the company plans to remain profitable if climate policies reduce global demand for oil and gas.