Gerry McGovern, author and developer of the Top Tasks method, has begun calculating the true ecological costs of online meetings. Called by The Irish Times as one of five visionaries who have had a major impact on the Web’s development, McGovern is quick to say that his calculations are works-in-progress. There’s so much that we rarely calculate in analyzing a product’s ecological impact—including, for example, the energy and toxins embedded in manufacturing concrete for a nuclear power plant or silicon for solar PV systems.

McGovern assumed that online meetings are better for the environment than physical meetings. He’s learned that this is not always the case. And even if online meetings are better, they can still harm the environment.

• A one-hour audio call consumes about 36 MB of data per person.
• A one-hour standard-definition video call consumes about 270 MB per person.
• A one-hour high-definition video call consumes about 540 MB per person.
• A one-hour ultra-high-definition video call consumes about 1.3 GB per person.

Assuming an average of one one-hour meeting per day involving two people, then, in the course of a year, simply transfer the data:

• Each audio-only call would emit 0.06 kg (2.1 ounces) of CO2.
• Each standard-definition video call would emit 0.5 kg (11 pounds) of CO2.
• Each high-definition video call would emit .9 kg (almost two pounds) of CO2.
• Each ultra-high-definition call would emit 2.3 kg (five pounds) of CO2.

But, this is just the tip of the iceberg when it comes to digital pollution. By far the greatest CO2 is generated by manufacturing, operating and discarding the devices. If we include emissions from a device’s full lifecycle, then:

• A smartphone is responsible for 27 g (0.9 ounces) of CO2 per hour of use.
• A laptop is responsible for 114 g (four ounces) of CO2 per hour of use.

If two people are on a call 250 days per year, that’s 500 hours of use per year. If the audio-only call is held on smartphones, and the video calls are held on laptops, then, per year:

• Audio-only calls would be responsible for a total of 13.6 kg (30 pounds) of CO2.
• Standard-definition video calls would emit a total of 57.5 kg (127 pounds) of CO2.
• High-definition video calls would emit a total of 57.9 kg (127.6 pounds) of CO2.
• Ultra-high-definition calls would emit a total of 59.3 kg (131 pounds) of CO2.

On average, a tree can absorb about 10 kg (22 pounds) of CO2 per year. For one tree to absorb the CO2 emissions of 250 hours of two-person audio calls, you’d need to plant 1.4 trees per year. To absorb the CO2 emissions of 250 hours of two-person video calls, you’d need to plant almost six trees per year.

The average CO2 emissions from operating (not manufacturing) new passenger, gas-powered cars registered in the European Union in 2018 was 0.1204 kg (4.2 ounces) of CO2 per kilometer. Thus, on a yearly basis:

• One audio-only call involving two people lasting one hour per day, 250 days per year, emits the same amount of CO2 as driving a gas-powered car 113 km (70 miles).
• One standard definition video call lasting one hour per day involving two people, 250 days per year, emits the same CO2 as driving 478 km (297 miles).
• One high-definition video call lasting one hour per day involving two people, 250 days per year, emits the equivalent of driving 481 km (299 miles).
• One ultra-high-definition call lasting one hour per day involving two people, 250 days per year, emits the equivalent of driving 493 km (306 miles).

The above estimates relate to the costs of using devices to stream online meetings. In many organizations, meetings are stored and watched later by others. This adds to the costs.

When Gerry McGovern assumed that an online meeting has less ecological impact than driving to it, he neglected several key factors. Now, he asks: How much goes into manufacturing and operating the access networks and data centers necessary to attend a meeting? What if people drive to the office and speak online with other people in that very office? How do online meetings increase the energy and rare earth consumed by manufacturing and operating data centers and access networks? What happens if far more people attend online meetings?

Based on his limited calculations, a meeting attended by 10 people using high-definition video could emit the equivalent of driving 2,400 km (1491 miles) per year. This is still a quite reasonable figure, but it does not consider manufacturing the access networks or data centers.

Then, if two or three or even four billion humans attend one online call for one hour, 250 days per year, well, that adds up to a lot of energy, extractions, greenhouse gases, water and electronic waste.

McGovern has often participated in online meetings with 20 to 100 people. Far more would have attended those gatherings if they had been held in a physical space. He believes that, if used wisely, digital can be better for the environment. However, time and time again, he has found that digital meetings accelerate, duplicate and encourage wasteful behavior. Digital is not green.

What’s better? No meetings, fewer meetings, short meetings, audio-only meetings or useful meetings.