Comprehensive Test Ban Treaty Organization (CTBTO)

HQ: Vienna, Austria

Focal Point: D.N.Wijewardane

Email: dharmakirthi.wijewardane [at]

Key Figures: Greenhouse gas emissions

Key figures: Waste

Key Figures: Water

Executive Secretary's message


"By banning all nuclear testing, the CTBT makes an important contribution to the environment. The combined yield of the nuclear tests conducted between 1945 and 1996, when the Treaty was opened for signature,  equals one 13 kiloton Hiroshima-sized bomb exploding every 53 hours for 51 years, exacting a terrible cost on human health and the environment. In the process of watching, listening and “sniffing” the globe for signs of nuclear explosions, our monitoring network also generates large amounts of data that help scientists better understand our planet, and are applied in a wide range of fields, from atmospheric and climate science, to recording earthquakes and tracking marine mammals."

Dr. Lassina Zerbo, Executive Secretary, CTBTO




CTBTO is the international organization established to ensure the build-up of a global verification regime capable of detecting nuclear explosions underground, underwater and in the atmosphere. The regime must be operational by the time the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which bans all nuclear explosions, enters into force. The verification regime consists of 337 monitoring facilities supported by an International Data Centre and on-site inspection measures in the event of a suspected nuclear test.


Experience so far


CTBTO conducts the majority of its job interviews since 2007 via video conference, drastically reducing the need for air travel.

By participating in the common energy saving and waste management measures with other Vienna Based Organisations at the Vienna International Centre, a carbon neutral UN hub, CTBTO plays an important part in reducing emissions.


EMS and Reduction efforts


CTBTO extended Business Class Travel eligibility to 9+ hours in May 2010, contributing to reduced carbon footprints.

Hotel accommodation and events bookings for CTBTO’s many conferences and workshops, including the leading biannual Science and Technology 2019 international symposium, are partnered mostly with select eco-friendly institutions near headquarters to minimise travel.

CTBTO promotes car pooling wherever possible between headquarters and its newly built TeST (Technology Support and Training) training and warehouse complex at Seibersdorf (Austria) to reduce emissions. Investments are being made to purchase electric passenger vehicles to service the TeST Centre in keeping with greening efforts

The organisation encourages an environmentally friendly approach to building and sustaining its leading network of International Monitoring System stations across the world that monitor for nuclear explosions; for example over half of the 51 certified Infrasound stations use solar power. Many stations are located inside national natural parks where construction and installation required specific approval from national park authorities and followed strict rules and regulations to preserve fauna and flora.  

Several stations feature other proactive measures :

IS20 (Galapagos) uses flexible hoses of wind noise reduction systems to preserve the natural landscape and minimise disturbance to endemic wildlife and fauna;  IS41 (Paraguay) uses rainwater collection systems to avoid transporting water overland for service needs.

CTBTO has constructed a new state of art facility in 2019 – the Equipment Storage and Maintenance Facility (ESMF) at Seibersdorf (Austria) with design features aimed at enhancing sustainability and reduction of energy consumption from non-renewable energy sources. A large solar array can power upto 80% of its needs. A subterranean heat exchange underneath the ESMF will reduce the need for electrical heating and air conditioning. Additionally electrical charging points for vehicles have been provided.

In pursuit of CTBTO’s heavy dependency on data and applications processing from its global stations, the organisation has invested in computer hardware conforming to green credentials with lower power consumption, more virtual servers to displace raw hardware, reduced heat emissions and automated controls to cut down on cooling leakages. Obsolete hardware is also being decommissioned according to Austrian environmental rules. 




CTBTO is considering carbon offsetting for 2019.


Waste Management


CTBTO consolidates waste management on every floor with the communal organisational efforts made at the Vienna International Centre.  All electronic waste is disposed of at Austrian environmental standards. 


Next Steps


CTBTO is considering carbon offsetting in 2019. With a major symposium called Science and Technology being hosted in Vienna in June 2019, we are taking steps to ensure an eco-friendly attitude and action for this large international gathering, minimising waste and printed matter, maximising use of recyclable materials, minimising the offsetting needs by using eco-friendly hotel partners and wherever possible environment friendly transportation modalities.  


CTBTO case studies