Top investors in Royal Dutch Shell (RDSa.L) on Tuesday put pressure on the oil and gas giant to commit to hard targets to reduce greenhouse gas emissions to battle climate change.  Shell has set out “ambitions” to halve carbon emissions by 2050 and expand in renewables, goals Chief Executive Officer Ben van Beurden said were ground breaking for the oil industry.  But he clashed with shareholders who had pushed climate to the forefront of the annual general meeting (AGM) and demanded Shell give specifics on how it would turn promises into action.  However, a motion that proposed setting targets was defeated...But a growing number of major shareholders... urged the Anglo-Dutch company to commit to firm targets to reduce carbon emissions from its oil and gas production, as well as from fuels it sells around the world.  “We call for this ambition to be translated into firm medium and short term targets, aligned with the Paris Agreement,” a group of 27 investors managing $7.9 trillion in assets said in a statement read at the AGM.  The group includes HSBC, BMO Capital Markets, AXA and UBS.  Shell’s board has urged shareholders to vote against a resolution brought forward for a vote at the AGM by activist group Follow This that called on Shell to set targets to reduce emissions and meet the 2015 Paris Climate Agreement goal that aims to limit global warming to “well below” 2 degrees Celsius.  The resolution was rejected by a majority of 95 percent...Although the Follow This motion was defeated, van Baal said companies were under more pressure to set clear goals...