What is Earth observation?

Earth observation is the gathering of information about planet Earth’s physical, chemical and biological systems. It involves monitoring and assessing the status of, and changes in, the natural and man-made environments.

In recent years, Earth observation has become more and more sophisticated with the development of remote-sensing satellites and increasingly high-tech in-situ instruments. Today’s Earth observation instruments include floating buoys for monitoring ocean currents, temperature and salinity; land stations that record air quality and rainwater trends; sonar and radar for estimating fish and bird populations; seismic and Global Positioning System (GPS) stations; and over 60 high-tech environmental satellites that scan the Earth from space.

Earth observation is now more important than ever due to the dramatic impact that modern human civilisation is having on the global environment.

What are Earth observations?

There are many different kinds of Earth observations. A few examples:

  • a birdwatcher’s notes on bird sightings
  • numerical measurements taken by a thermometer, wind gauge, ocean buoy, altimeter or seismograph
  • photographs
  • radar and sonar images
  • analyses of water or soil samples
  • processed information such as maps or forecasts

Why are Earth observations important?

Human civilisation is having an increasingly powerful influence on the Earth system. Earth observations are invaluable for assessing and mitigating the negative impacts. They can also be used for exploiting new opportunities, such as the sustainable management of natural resources. Some specific applications of Earth observations include:

  • forecasting weather
  • tracking biodiversity and wildlife trends
  • measuring land-use change (such as deforestation)
  • monitoring and responding to disasters, including fires, floods, earthquakes and tsunamis
  • managing energy sources, freshwater supplies and agriculture
  • addressing emerging diseases and other health risks
  • predicting, adapting to and mitigating climate change