Introduction: Green Energy and Technology

To reduce greenhouse gas (GHG) emissions and meet Paris Agreement targets, nationally determined contributions have been made by every country in the world. Many countries are aiming for a net zero emission target, however, net zero has been defined differently country to country making unified emission reductions more difficult. Transport and energy generation remain the two largest global emitting sectors and substantial transformation will be required to meet emission reductions. Internal combustion engine vehicles for personal use remain the highest emitting transport type, which has led to governments and policymakers introducing legislation to ban and phase out their sale over the coming decades in favour of low carbon alternatives, including electric and hydrogen fuelled vehicles. Although electric and hydrogen transport are considered ‘zero emission’ at their point of use, their true environmental impact is determined by the source of the electricity used to ‘fuel’ these vehicles. Therefore, an integrated and interdisciplinary approach to meet net zero will be required as there will need to be trade-offs between GHG emission reductions, climate regulation and the potential impact upon ecosystem services. By integrating alternative fuels and encouraging travel behaviour to support public transport, which has a lower level of emission per person per kilometre travelled, there is the potential to have a significant impact on emission level reduction. Taking into consideration experience from different countries that have successfully implemented pathways towards low carbon transport, lessons can be learnt from the best policies and decarbonise both the transport and energy sectors.