Context: The US administration has asked the National Aeronautics and Space Administration (NASA) to prepare to shut down Orbiting Carbon Observatories (two major satellites) that monitor atmospheric Carbon dioxide (CO2) and crop health.
The missions, still working perfectly, are being terminated to align with the US budget priorities.
Relevance of the Topic: Prelims: Key facts about Orbiting Carbon Observatories; Carbon dioxide.
Orbiting Carbon Observatories
- OCOs are a series of dedicated Earth remote sensing satellites designed specifically to observe atmospheric CO2 from space to better understand the characteristics of climate change. The two OCOs include: OCO-2 (launched in 2014) and OCO-3 (2019).
- Function: The satellites:
- measure atmospheric CO2 and can also locate its sources and sinks.
- track crops and crop-growing seasons by measuring the glow that plants emit when they photosynthesise.
- OCO-3 and OCO-2 do the same function, but they provide different perspectives to scientists.
- OCO-2 flies around Earth in a sun-synchronous polar orbit which allows it to see any given location at the same time of day.
- OCO-3 flies aboard the International Space Station (ISS) which orbits Earth every 90 minutes. It can observe a location at many different times of day, and add to the dataset of its predecessor mission.
The US government now plans to shut down both OCO-2 and OCO-3 satellites. The satellites are more sensitive and accurate than any other mission operating or planned, in the world.
Significance of the OCO Missions
Before the launch of the OCOs, scientists measured atmospheric CO2 mainly through instruments placed at various locations on the Earth’s surface. However, this did not provide them information about the whole planet.
- Provide a range of Data: OCOs have the ability to monitor crop health. NASA and other agencies have used the data to create high-resolution maps of plant growth around the world. The data generated by OCOs is used:
- For CO2 measurement
- To forecast and track crop yields and drought conditions
- For drought monitoring
- Forest mapping
- To assess emission reduction efforts, and to develop effective strategies to tackle climate change.
- Advance scientific knowledge: OCOs have advanced scientific knowledge by paving the way for some surprising discoveries. For instance:
- For decades, it was believed that tropical rainforests functioned as the lungs of the planet by clearing out vast quantities of CO2 from the atmosphere. However, data from OCO-2 revealed that boreal forests (also known as taiga), the coniferous forests in the higher latitudes of the northern hemisphere, play a significant role in the absorption of CO2.
- The data showed how natural carbon sinks such as forests could become carbon emitters due to drought or deforestation.
About Carbon dioxide
- Carbon dioxide, a colourless gas, is one of the most important greenhouse gases linked to global warming. It is a minor component of Earth’s atmosphere (about 3 volumes in 10,000).
- Sources of Emission:
- Natural: Respiration, decomposition of living animals, fermentation, emitted from oceans and other natural bodies of water, volcanoes, forest fires, and carbonate rocks.
- Anthropogenic: Transportation, power and heat generation, chemical and petrochemical production, manufacturing, agriculture, food production.
Global Warming Potential:
- GWP describes how much impact a gas will have on atmospheric warming over a period of time compared to carbon dioxide. Each greenhouse gas has a different atmospheric warming impact, and some gases remain in the atmosphere for longer than others.
- Carbon dioxide (CO2) has the lowest global warming potential, is the most abundant and lasts for thousands of years, so it is used as the baseline.