As the number of air passengers booms, carbon emissions by the civil aviation sector are contributing significantly to the increase in greenhouse gases that exacerbate climate change.

By 2050, carbon emissions by the international aviation sector are likely to grow seven-fold, according to the International Civil Aviation Organisation. Acknowledging the sector’s responsibility to help protect the planet, the International Air Transport Association has committed to improving fuel efficiency by 1.5% per year from 2009 to 2020, and stabilising carbon dioxide emissions in preparation for a 50% reduction by 2050.

With air passenger traffic in India growing between 16% and 18% between 2015-2018, it’s clear that the country’s aviation sector must do its bit to cut emissions. What exactly can it do to become greener? Here are four suggestions.

1. Improved air traffic management

To begin with operations could be significantly improved – and emissions cut – by reducing the time an aircraft spends in the air. This could be achieved by optimising the use of runways and terminals, improving air traffic management and deploying efficient navigation systems. A reduction in aircraft taxiing time on the runway by just 120 seconds could result in savings of 5, 000 kg of fuel burn and 15 tonnes of carbon emissions per day.

In Singapore’s Changi Airport, an Airport Collaborative Decision Making platform allows Air Traffic Controllers to sequence the departure of flights in advance based on expected readiness of flights. This helps to reduce the waiting time for departures and to cut taxiing time.

The Civil Aviation Authority of Singapore has used air traffic management procedures to shorten flight routes, which have resulted in significant fuel savings. The procedures have also helped reduce air traffic congestion over the South China Sea and Bay of Bengal, cutting down at least 50,000 tonnes of CO2 emissions each year.

Similar measures are already being adopted in some Indian airports. In Mumbai, for instance, the Chatrapati Shivaji Maharaj International Airport on December 8, 2018, recorded 1,007 aircraft movements, a world record for the largest number of flight movements on a single runway in 24 hours. This was achieved by ensuring the optimal utilisation of the runway and air space capacity, deploying advanced communication systems and improving air traffic management.

2. Sustainable alternative fuels for aircraft

The development of sustainable alternative aviation fuel – advanced biofuels used in jets – is a major breakthrough. Completely substituting conventional aviation fuel with sustainable alternative fuel could reduce CO2 emissions from international flights by 63% by 2050, says the International Civil Aviation Organisation.

Since 2008, when the first flight using sustainable aviation fuel took off, a great deal of progress has been made in this regard. At present, five airports – Oslo, Stockholm, Bergen, Los Angeles and Brisbane – are regularly supplied with sustainable aviation fuel. Others like France’s Caen airport offer occasional supply. As per an IATA fact sheet in May, “several airlines have signed significant off-take agreements” to purchase sustainable aviation fuel.

Since 2011, it said, 180,000 commercial flights have been operated using sustainable aviation fuel. In August 2018, Spice Jet operated India’s first flight using biofuel made from the jatropha plant. The flight ran between Dehradun and Delhi.

3. More fuel-efficient technology

Innovative technological arrangements could improve the fuel efficiency of aircraft engines. Today’s aircraft use roughly 80% less fuel per passenger-mile than the first jets of the 1950s. Such developments such as lightweight materials, winglets and aircraft design change could improve fuel efficiency.

In January 2017, the American Institute of Aeronautics and Astronautics demonstrated its efforts to optimise the design of aircraft wings built with new composite materials and emerging construction methods. NASA is also working with prototypes, such as a “blended wing body” aircraft that would reduce weight and increase fuel efficiency.

4. Greener airports

Building green airports with environmentally friendly infrastructure and renewable sources of energy is also essential. Some airports are investing in offsetting schemes to become carbon neutral, carbon accreditation programmes and building green-certified terminals .

Among the features that have proved effective in reducing the energy consumption are LED lights. Queen Alia International Airport in Jordan, for instance, operates an LED-lit runway that reduces carbon emissions by 495 tonnes annually, electricity consumption by 779,454 KWH and has resulted in annual savings of around $136,130.

In 2015, Cochin international airport became the first airport in the world to be fully powered by solar panels. This helped it reduce its carbon footprint by over 3 lakh metric tonnes – equivalent to planting 3 million trees.

London’s Heathrow airport has been operating on 100% renewable electricity since April 2017.

Just don’t do it

Besides these changes for the aviation industry, awareness among passengers about protecting the environment is vital. Some have already begun to push the idea that the less people fly, the better it is for the environment. For instance, two Swedish mothers have started an initiative to attempt to persuade 10,000 individuals, not to take flights in 2019. Trips could be eliminated by option to travel by train, for instance or using video calls instead of making business trips.

Measures like these may help in minimising the carbon footprint, which is vital to reducing greenhouse gasses.

Mukesh Yadav is an urban planner and a member of the practice team at the Indian Institute for Human Settlements. He works in the fields of urban planning, governance and policy advisory using remote sensing and GIS as a tool.