While there are differences in energy yield per unit of greenhouse gas emitted between the main types of fossil fuels – with high efficiency natural gas being more than twice as efficient as the lowest grade coal, all fossil fuels still contribute actively to atmospheric GHG concentrations and so should not be considered as part of “green technology”. Some people view natural gas as an important “transition” fuel and it certainly has taken that role in recent years. But labels do have some significance – burning natural gas still makes the problem worse and takes society further away from the path we need to be on – just at a slower rate than coal.
I’ve also titled this page “greener” energy rather than green energy or renewable energy, because many of the technologies discussed still do have a GHG footprint (albeit smaller than fossil fuels) and may not be 100% renewable.
Of the world’s energy consumption, in recent years, about 76% has come from fossil fuels and another 6% has come from traditional biomass (which is often harmful to human health and also acts as a greenhouse gas – but not with quite the same level of carbon emissions). Of the 18% from renewables, about 6% has been from hydropower, 4% from nuclear, about 3.5% from wind, about 2% from solar and the remaining few percent from biofuels and other renewables.
source: Global Energy Mix
With regard to electricity production, oil plays a smaller role than with total energy production and renewable energy plays a proportionally larger role – constituting about 40% of the total. Hydropower constitutes about 15% of the total electricity production, nuclear about 9%, wind about 7%, solar about 4.5%.
source: Global Electricity Mix
Below are links to explanations of different greener energy technologies, some carbon negative technologies and engineering ideas and developments in electric vehicles and green building design.
asclimateservices.org 