Brussels wants to tighten rules to prevent some forms of wood-burning energy from counting towards the EU’s green energy targets after rising pressure from environmental groups and scientists.  The European Commission will propose strengthening its “sustainability criteria” to measure whether forms of biomass — which involves combustible pellets made from wood or organic waste — should be considered as renewable, according to a leaked document seen by the Financial Times.  Biomass makes up nearly two-thirds of the renewable energy in the EU, dwarfing output from sources such as wind and solar power.  ...