Airliner with contrails, above the Pyrenees, France.
Aviation is one of the fastest growing sources of greenhouse gas (GHG) emissions and the most climate-intensive form of transport. Aviation emissions have more than doubled in the last 20 years and the sector is responsible for an estimated 4.9% of man-made global warming - and growing 21% in EU in last three years). While other sectors are working to decarbonise, there's no sign of any viable alternative to fossil fuelled flight anytime soon - electric engines are a long way off. Flying seems, cheap, and it seems easy, but it's actually expensive - and we've yet to pay the cost. In the EU, many tickets are VAT-exempt, costing governments €17 billion annually. If applied, tickets would cost, around 20% or so extra, depending on where you live. Plus, Fuels used in commercial aviation are exempt from excise duties in the EU. (Facts from Transport & Environment website).