Greenhouse Gases Shrinking Earth’s Orbital Space for Satellites
Why in the news
A study found that human-caused greenhouse gas emissions will contract the upper atmosphere, reducing how many satellites low Earth orbit can safely hold.
Key facts
- Layers shrinking: the mesosphere and thermosphere.
- Safe satellite carrying capacity falls by 50% to 66% by 2100.
- Under SSP5 8.5, safe capacity in low Earth orbit (LEO) may fall to about 25-40 million satellites.
- Lower atmospheric drag lets debris linger, increasing collision chances.
- Team from MIT led by Dr. William Parker built atmospheric models for different emission scenarios, with the year 2000 as the baseline.
- Satellite re-entry rates drop markedly as CO2 emissions move from moderate to high.
About greenhouse gases
| Gas | Main sources |
|---|---|
| Carbon dioxide (CO2) | Burning coal, oil and natural gas; most abundant GHG |
| Methane (CH4) | Livestock, landfills, natural gas production |
| Nitrous oxide (N2O) | Agriculture, industry, fossil fuels |
| Fluorinated gases | Synthetic; refrigeration and industry |
- GHGs trap heat; this natural greenhouse effect keeps Earth habitable but intensifies with human emissions.
- Other emission sources: industrial processes such as cement, deforestation and waste management.
Way forward
- Cut greenhouse gas emissions, which matters for long-term use of orbital space too.
- Improve debris management and set international rules on satellite end-of-life decommissioning.
Exam angle
- Scenario name: SSP5 8.5 (high emission).
- Layers: mesosphere, thermosphere; orbit: LEO.