What space can teach us about the environment

Before satellites were first launched into space in the mid-20th century, we knew very little about the dynamics of our climate. Today, numerous satellites collect information which helps us piece together the story of our changing planet. In 1985, they helped discover the hole in the ozone layer, and data from space remains key to tackling global warming.

Some satellites monitor signs of climate change, such as melting ice caps, rising sea levels and amounts of CO2 in the atmosphere. The Jason-3 satellite (pictured), launched in 2016, can make precise measurements of global sea levels, a key indicator of climate change. The data will give us a stronger understanding of just how our oceans are being affected by increased temperatures.

Space technology has paved the way for the development of increasingly sophisticated surveying and monitoring tools which can track everything from deforestation to illegal fishing ships and even oil spills. This way, researchers know exactly when and where environmental — and legal — action needs to be taken.

Satellites play a vital role in tracking natural disasters such as hurricanes, wildfires and floods. As well as providing an early warning for those on the ground, they also help authorities track the intensity of the event and understand the scale of the devastation. Monitoring storm systems helps generate better climate models to predict future disasters.

Growing plants in space has already taught us valuable lessons which can be applied to sustainable agriculture on Earth. Astronauts on the International Space Station have discovered they can use less water to grow vegetables, and China recently made history by germinating a cotton seed on the far side of the moon. As our planet warms, this knowledge could be vital for farmers.

Unfortunately, space technology has also had a negative impact on the environment. Every time a rocket is launched it produces a plume of exhaust smoke filled with bits of soot and a chemical called alumina, which can build up in the stratosphere and deplete the ozone. Space agencies are looking to lessen their use of "ozone-depleting substances" and are researching more eco-friendly fuels.

There are currently more than 20,000 trackable pieces of space junk in orbit around Earth, including everything from old rockets to bolts and screws. They're not technically part of Earth's ecosphere, but if we're not careful the junk may become so dense that satellites won't be able to function properly and provide us with the data we so desperately need.