Youssef Khalil / Nature

Innovation Feature

Monitoring Greenhouse Gases

KACST researchers are developing an innovative system to monitor nationwide greenhouse gas levels and inform reduction strategies.

5 January 2019

Almost 200 countries, including Saudi Arabia, have shown their commitment to minimize further rises in global temperatures by signing the Paris Agreement, which largely aims to reduce greenhouse gas emissions. To achieve this, KACST researchers are developing a smart system for monitoring greenhouse gas levels across the country.

There is a need to reduce greenhouse gases in the Arabian Gulf region, as recent evidence suggests that the temperature and humidity in this area are likely to rise to a level that could threaten its habitability. KACST’s smart monitoring system will contribute to the Saudi Arabian government’s Vision 2030. “One strategic objective of Vision 2030 is to offer a fulfilling and healthy life,” says Badr Alharbi, the project’s technical leader and the director of the National Center for Environmental Technology at KACST. Alharbi is also a member of the Saudi delegation to the United Nations Framework Convention on Climate Change. “Our project contributes to this [goal] through monitoring greenhouse gases and facilitating decision making and mitigation strategies. We strive to protect our environment by deploying advanced, yet cost-effective technologies to help the Saudi government have more control over greenhouse gas emissions.”

The development of the smart system involves the fabrication of sensors that detect atmospheric levels of carbon dioxide and methane, and their integration into a wireless sensor network (WSN) to enable data gathering from across the country.

Advanced sensors that offer highly accurate gas analyses are being developed by the Japanese company Horiba. KACST is also developing smaller, cheaper, but less accurate sensors. “The high-accuracy sensors are expensive, so a limited quantity will be deployed in well-selected areas to maximize their benefit,” explains Yasser Seddiq, from the National Center for Communication Systems and Command and Control Technology. “The small nodes are much cheaper, providing incentive to use them in most WSN terminals. Our approach aims to create a compromise between cost and accuracy by using both types of equipment in the WSN.”

The system setup

The placement and distribution of sensors within the network will ensure comprehensive and representative coverage of the country. Ten cities have been selected for the high-accuracy sensors on the basis of their geographical locations and the nearby industrial activities that might contribute to greenhouse gas emissions; namely Riyadh, Jeddah, Dammam, Yanbu, Abha, Khafji, Qassim, Najran, Arar and Tabuk.

The low-cost sensors will be installed in areas affected by emissions from these cities. To identify appropriate sites for them, the researchers investigated the dispersion of gases around each of the 10 cities using a model of atmospheric transport and dispersion to simulate air movements. “Wider plume dispersion and larger coverage area were observed for plumes released from Jeddah, Yanbu and Qassim, which suggests that these three cities contribute to greenhouse gas concentrations in neighboring cities,” says Alharbi. “Neighboring cities should therefore be considered potential locations for additional low-cost gas monitoring devices.”

The system also determined that high levels of greenhouse gases are carried to Riyadh at certain times of the year by winds that travel over the Arabian Gulf, where industrial emissions from oil refineries and gas flares are high. The same approach indicated a source of greenhouse gases in Iraq.

To make use of the information gathered by the gas sensors, the data needs to be centralized and integrated for analysis. The geographical spread of the sensor locations makes this challenging, as an extensive IT infrastructure is costly, and energy consumption needs to be minimized. To address these difficulties, Alharbi and his colleagues are planning to use Internet-of-things technology. Remote sensors will be connected to the data center via the internet, and will send the information they collect from an in-built communication module. “This kind of communication technology features a lower cost, more efficient use of bandwidth, and more efficient energy consumption compared to ordinary cellular communication devices, which are usually used in similar contexts,” says Alharbi.

The project was launched in February 2017, more than 18 months later, Alharbi says it is 30 percent  complete. “The main achievements so far are the identification of cities and locations of monitoring devices that are representative of the levels of greenhouse gases in the kingdom; the design and development of the initial experimental communication model for the transfer and review of measurement data; and the development of low-cost, small-sized carbon dioxide analysers,” he says.

The next step in the project is installing the high-accuracy sensors. This will involve installing and calibrating sensors in Riyadh, Khafji, and Qassim first, and then in the remaining seven cities. That’s when the Internet-of-things technology will be deployed to set up connections between the installed devices and the data centre. Low-cost methane sensors will then be developed and optimized, installed in appropriate sites and integrated into the network. The system will then be ready for monitoring greenhouse gas levels.

The researchers hope to complete setting up their system by the end of 2019, when the information will start being collected and put to use. “The sensing system developed in our project will provide detailed information about greenhouse gas concentrations, their hotspots and their spatial and temporal distribution in Saudi Arabia,” says Alharbi. The data will enable the researchers to assess the warming effect of the greenhouse gases and determine the contribution of these gases to climate change in the country. This combined information will help the government develop strategies for reducing emissions; which is the primary purpose of the smart system. Alharbi adds, however, that the system could also be used to monitor progress against greenhouse gas reduction targets, such as those set out by the Paris Agreement.

If the technology is successful, its use could extend beyond Saudi Arabia. “Due to the expected technological efficiency, accuracy and cost of the system, it is highly possible for other countries to employ the system we are developing for similar purposes,” says Alharbi.