The increasing levels of anthropogenic greenhouse gas emissions in the atmosphere may reduce the total number of satellites that can be in a safe orbit around the earth up to 66% of today’s bearing capacity. This is found in a study published in the journal Nature Sustainability.

Previous studies have found that the increasing amount of carbon dioxide and other greenhouse gases in the atmosphere can cause a shrinkage of the upper atmosphere of the Earth, consisting of the Mesosphere and thermosphere. The Thermosphere is of particular interest, as the International Space Station and most satellites are on track. When the heat shrinks, the reduced density reduces the atmospheric resistance, which pulls old satellites and other debris downwards, at high heights. Therefore, less resistance means longer life for space garbage and therefore increasing the probability of orbit conflicts.

The researchers, led by MIT, attempted to appreciate through simulations the number of satellites that can be sustainable on an earthly orbit of up to 2100 under different broadcast scenarios. The team compared different scenarios: one in which greenhouse gas concentrations remain at 2000 levels and others in which emissions change in accordance with the intergovernmental committee for climate change. In the highest emission scenario, they found that the maximum number of satellites that can be sustained in a low-ended-legged way would be 50-66% smaller to 2100, depending on solar activity.

Researchers note that the mitigation of greenhouse gas emissions is not only important for the climate of the Earth, but also for maintaining our access to space.