Why in NEWS
The US has directed NASA to prepare for the early termination of two critical satellites—OCO-2 and OCO-3—that track atmospheric carbon dioxide (CO2) and monitor crop health.
Key Terms/Concepts
| Term | Explanation |
|---|---|
| OCO (Orbiting Carbon Observatories) | NASA’s satellites designed to track CO2 levels and plant health. |
| CO2 (Carbon Dioxide) | A major greenhouse gas responsible for global warming and essential for life. |
| Carbon Sinks | Natural systems like forests and oceans that absorb CO2. |
| Carbon Sources | Systems or processes like fossil fuel use and deforestation that emit CO2. |
Key Points
| Aspect | Details |
|---|---|
| OCO-2 (2014) | Measures atmospheric CO2, identifies sources and sinks, tracks photosynthesis through plant glow; sun-synchronous polar orbit. |
| OCO-3 (2019) | Installed on ISS, provides observations of same locations at different times of the day; complements OCO-2 data. |
| Significance | Offers high-resolution global CO2 data, reveals role of boreal forests, shows sinks can turn into sources during droughts/deforestation, aids emission policy formulation. |
| Discovery | OCO-2 revealed boreal forests absorb more CO2 than tropical rainforests, shifting understanding of global carbon sinks. |
About CO2 & Global Carbon Cycle
| Aspect | Details |
|---|---|
| Nature | CO2 traps heat, maintaining Earth’s atmospheric balance. |
| Sources | Fossil fuels, respiration, deforestation, organic decay. |
| Sinks | Vegetation, forests, oceans (absorb ~50% of human CO2 emissions). |
| Global Carbon Cycle | Exchange of carbon among atmosphere, oceans, land, and fossil fuels—from photosynthesis (seconds) to fossil fuel formation (millennia). |
In a nutshell
OCO satellites transformed climate science by revealing the critical role of boreal forests and providing unprecedented CO2 insights—ending them may leave a data gap in global climate monitoring.
Mnemonic: “OCO = Observing CO2 Origins”
Prelims Practice Questions
- Which of the following statements about OCO satellites is correct?
a) OCO-2 was launched in 2009 but failed due to a fairing issue.
b) OCO-3 orbits Earth in a sun-synchronous polar orbit.
c) OCO-2 tracks photosynthesis using plant fluorescence.
d) Both (a) and (c). - Boreal forests play a crucial role in carbon absorption, as revealed by:
a) IPCC Report 2014
b) NASA’s OCO-2 data
c) Paris Agreement findings
d) FAO reports - Consider the following regarding the Global Carbon Cycle:
1. It includes exchanges between atmosphere, oceans, land, and fossil fuels.
2. It occurs only over short time scales like photosynthesis and respiration.
3. Fossil fuel formation is part of the cycle.
Which of the above are correct?
a) 1 only
b) 1 and 3
c) 2 and 3
d) 1, 2, and 3
Answer Key for Prelims
| Qn | Answer | Explanation |
|---|---|---|
| 1 | d | OCO-2 was successfully launched in 2014 after the 2009 failure; it measures photosynthesis glow. |
| 2 | b | OCO-2 revealed boreal forests’ significant role in carbon absorption. |
| 3 | b | Carbon cycle includes long-term (fossil fuel formation) and short-term (photosynthesis), hence 1 and 3 correct. |
