www.supplychainbrain.com/articles/22895-fifty-european-airports-scheduled-to-be-carbon-neutral-by-2030

Fifty European Airports Scheduled to Be Carbon-Neutral By 2030
December 8, 2015
To attain carbon neutrality, a facility must emit no net carbon, often by offsetting its emissions with some other clean energy source – for example, replacing fossil fuels with solar panels.
The intergovernmental panel on climate change reported that aviation's total CO2 emissions amount to 2 percent of global emissions. Airport operations account for up to 5 percent of that total, the panel said.
There are 20 carbon-neutral airports in Europe at present.