## 4 What Will the Energy Be Used For?
### Transport  
Globally, transport, both passenger and freight, is only second to industry for energy use, and in 2020 accounted for 37% of final total energy demand [22], and 15% of total global GHG emissions, as noted above. Since 1900, there has been an extraordinary rise in both transport energy and activity, far exceeding the rise in global GDP [56], suggesting that significant energy reductions in transport could be achieved by reducing both. There is another important reason for cutting both transport energy and the transport task. At present, global transport is still heavily reliant on oil, with its share only falling from 94.3% in 1973 to 91.7% in 2018 [22]. Electric vehicle (EV) advocates argue that with a switch to EVs as a replacement for petroleum-fuelled transport, the CC damages from transport can be negated, and vehicular air pollution greatly cut. However, vehicular transport produces a variety of other serious environmental externalities which will still occur even if all road-based transport was replaced by EVs powered by RE [57; 58]. These externalities include: traffic collision fatalities, which now number about 1.3 million deaths annually; light pollution; road penetration into wilderness areas, including formerly pristine forest areas; air pollution from tires and brake linings; the urban heat island (UHI) effect, partly caused by reduced evapotranspiration as sealed roads and car parking areas replace vegetation; and community disruption in heavily trafficked urban areas. Although vehicle exhaust emissions are zero for EVs, the pollution from EV battery disposal and recycling is already serious [59], and far greater for EVs than for conventional vehicles, because of their much greater battery capacity. In summary, reducing vehicular travel will have multiple benefits for the environment, compared with, say, lowering the thermostat for domestic gas heating. How could transport energy and activity be greatly reduced, particularly in the high-mobility OECD countries? Many energy researchers (see, e.g., [60; 61]) have seen large improvements in energy efficiency of transport vehicles (as well as in other sectors such as buildings, and industry) as having a key role in both reducing energy use and mitigating climate change. Although there has been some improvement in the energy efficiency of the various transport modes, it has not translated into transport energy (or CO\({}_{2}\)) reductions. Various factors, such as the shift to more energy-intensive modes and models (cars replacing public transport, sports utility vehicles replacing ordinary sedans), energy rebound, and greatly increased car ownership in non-OECD countries, have led to final energy use in transport--both passenger and freight--rising from 45.2 EJ in 1973 to 105.1 EJ in 2020 [22; 28]. A different approach is to change the priority we presently accord to the three surface passenger transport modes--private car, public transport, and non-motorised travel. At present, public transport modes account for an estimated 30% of all surface vehicular travel [58], although its share in cities is usually higher. Priority could be reversed by reducing the travel convenience of the car, through measures including speed limit reductions, reduced parking availability, and traffic-free zones in the inner areas of cities [57]. At the same time, the convenience of competing modes, especially non-motorised modes, could be improved. The changes could be readily justified by the need to cut traffic casualties and other environmental damages already discussed. One promising development in motorised transport is the growth in use of e-bikes, especially in China, which dominates global sales [62], and where e-bikes significantly outnumber EVs [63]. E-bikes, which typically operate at much lower speeds than other motorised modes, not only have significantly lower energy use per km than other motorised modes, but also have significantly lower life cycle GHG emissions [62].