A new satellite has a mission to map the world's oceans, lakes and rivers. It is called SWOT – Surface Water and Ocean Topography. Data from the satellite will help scientists monitor how climate change is affecting water levels. A journalist said: "SWOT is needed more than ever, as climate change worsens droughts, flooding and coastal erosion." NASA said SWOT was of "pivotal" importance. It said it would change how we see Earths water.

The car-sized satellite took 20 years to make and cost $1.2 billion. High-precision radar will measure the water on 90 per cent of Earth's surface. It will survey 2.1 million kilometres of rivers. It will find areas of water loss that could threaten populations and coastlines. NASA said: "SWOT will give us a ten-fold improvement in the [accuracy] of our measurements of water height." Scientists will understand more about the role oceans play in climate change.