Universiteit Leiden

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A large proportion of the University’s total carbon footprint under normal circumstances is caused by home-to-work commuting, home-to-study commuting, visitor traffic, business travel and goods transport to and between University locations.

Leiden University has over 60 locations, more than 7,600 staff and over 33,000 students. We also receive a large number of visitors each year. This means that thousands of transport movements take place every day.

Business travel

For international business trips, Leiden University has decided that travelling by train is the standard mode within a radius of 500 kilometres or a travelling time of six hours or less.

The number of business trips has fallen sharply since 2020, when the coronavirus pandemic began. Of necessity, the use of sustainable communication alternatives, such as teleconferencing and MS Teams, has greatly intensified.

The business trips made by staff in 2021 accounted for just 6.5 percent of the University’s total (gross) carbon footprint. Very few of these trips took place by air in 2021, but under normal circumstances air travel would account for a large share of our carbon footprint. In the years ahead, we will therefore focus mainly on reducing or compensating for the carbon footprint due to air travel.

Since 2016 we have kept a record of the CO2 emissions of all business trips by air. In 2020 the CO2 emissions of 2018, 2019 and 2020 were compensated with green certificates. Research by students of the University’s Institute of Environmental Sciences (CML) partly formed the basis of awarding contracts for the carbon compensation of air travel.


In 2021 the Terms of Employment Individual Choices Model gave staff the additional option of a battery for their own electric bicycle. Once every three years at most, the University provides an allowance for purchasing a bicycle for home-to-work commuting up to a maximum of 1,500 euros or a battery for an electric bicycle up to a maximum of 750 euros. A bicycle battery wears out more quickly than the bicycle itself, so a new bicycle is not always necessary. We thus offer a more sustainable solution for staff who use their bicycle for commuting.

Looking ahead

In 2022 we have investigated ways in which business trips, both national and international, can be further avoided, reduced or made greener. Our aim is to eliminate carbon compensation as far as possible, so that we actually achieve more sustainability.

Sustainable Development Goals

Our mobility policy contributes to these Sustainable Development Goals of the United Nations:

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Icon for the SDG
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