According to this year's Greening the Blue report, over 50% of the United Nations‚2016 greenhouse gas emissions came from travel. In total, travel was the source of 1.03 million tonnes of carbon dioxide equivalent (tCO2eq) last year. Air travel comprised 42% of the UN‚Äôs total emissions, with 12% coming from other forms of transport (e.g. trains, official vehicles, etc.). The remaining 46% came from UN facilities, such as Headquarters, field offices, workshops, etc Travel and transport includes the travel of staff, meeting participants and experts, as well as the transport of supplies and different forms of aid around the world. With such high levels of emissions coming from one activity, there are clearly opportunities to improve efficiency. This can be done in a number of ways, such as avoiding unnecessary trips, making better use of technology or by using more efficient modes of transport.

With UN staff members relying on air travel for crucial work missions it's not always easy to find alternative options. That said, where lower-carbon forms of transport exist ‚such a trains ‚the emissions reductions can be significant. A great example of walking the talk‚can been seen in WHO's Assistant Director-General's journey to COP23‚In her first official function as Assistant Director-General for Climate and other Determinants of Health, Dr. Joy St John traveled by train from Geneva to the UN Climate Change Conference (COP23) in Bonn, Germany. WHO Assistant Director-General, Dr. St. John travels to COP23 by train from Geneva ‚Our personal decisions about transport can make a difference to reducing our impact on the environment. I was determined to take the train to COP23 because the climate change team told me it produced the lowest carbon footprint,said Dr. St John.The journey took around 8 hours, twice as long as it would have by airplane (with three changes), but it was a pleasant way to travel and I managed to do some work and get some rest on the way.

Travelling by train is significantly more environmentally friendly than by plane or car for the same distance. For the journey of more than 600km from Geneva to Bonn, a train emits 16.7kgs of carbon dioxide, a car 66.3kg and an airplane 184.4kg. Train travel also consumes 1/7 of the energy, and emits less than 1/5 the volume of particulate matter compared to air travel. ‚This was my first COP and I was eager for the opportunity to meet key stakeholders and potential partners. I really want to advance the work required for WHO to demonstrate impact in the programme designed to protect people's health from the impact of climate change. The Paris Agreement is an enormous opportunity for countries to improve the health of their people while cutting carbon emissions, she says.WHO used Eco Passenger to calculate the carbon footprint of Dr. St John's travel.

For more information about the World Health Organization's work on climate change visit www.who.int/globalchange/en/.