Greenhouse gases trap heat and make the planet warmer.
Several of the major greenhouse gases occur naturally but increases in their atmospheric concentrations over the last 250 years are due largely to human activities. Other greenhouse gases are entirely the result of human activities. [IPCC’s Fourth Assessment Report]
Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities.
In 2017, CO2 accounted for about 81.6 percent of all U.S. greenhouse gas emissions from human activities.
Emissions of CO2 from fossil fuel use and from the effects of land use change on plant and soil carbon are the primary sources of increased atmospheric CO2.
For total U.S. CO2 emissions, which mainly come from the combustion of fossil fuels (coal, natural gas, and oil), by economic activity types, transportation accounts for about 34.2 percent, electricity accounts for about 32.9 percent, industrial processes accounted for about 15.4 percent.
1. Passenger Vehicles Going Electric
An analysis by the International Council for Clean Transportation (ICCT), shows an estimate of lifecycle emissions for a typical European conventional (internal combustion engine) car, the hybrid conventional car with the best available fuel economy (a 2019 Toyota Prius Eco), and a Nissan Leaf electric vehicle (best-selling EV overall in Europe for 2018) for various countries, as well as the EU average.
An electric car using average European electricity is almost 30% cleaner over its life cycle compared to even the most efficient internal combustion engine vehicle on the market today
In most countries, the majority of emissions over the lifetime of both electric and conventional vehicles come from vehicle operation – tailpipe and fuel cycle – rather than vehicle manufacture. The exception is in countries – Norway or France, for example – where nearly all electricity comes from near-zero carbon sources, such as hydroelectric or nuclear power. Lifecycle emissions for electric vehicles are much smaller in countries such as France (which gets most of its electricity from nuclear) or Norway (from renewables). [carbonbrief]
There is an important variable here – how the batteries of EVs are produced, as the largest part of the emissions, around 50%, is currently from battery (including cell) manufacturing.
Producing batteries in a plant powered by renewable energy – as will be the case for the Tesla factory – substantially reduces lifetime emissions. The IVL researchers estimate that battery manufacturing emissions are between 61 and 106 kg CO2-equivalent per kWh.
With the technology advancements and cleaner energy sources for plants, the marginal and average cost of producing batteries will continue to go down.