China's National Space Administration (NSA) warned that there is an increasing danger of collisions between spacecraft and countless debris lying around space.
The NSA estimates that if the situation does not change, a large space collision will happen every four to nine years.
Liu Jing, vice director of the Space Debris Monitoring and Application Center under the NSA, said that China's satellites face the risk of coming close to debris every month.
He added that lack of effective measures will cause a chain reaction between space debris that will bring intensification of space to a critical point.
The NSA estimates that over 23,000 pieces of debris larger than 10 cm and over 500,000 pieces larger than 1 cm are in space.
In addition, there are more than 100 million debris larger than 1 mm.
These were shown by NSA as countless dots in a simulation diagram on a computer.
Liu revealed that mankind has launched more than 6,000 spacecraft, with some 1,300 still in operation, while others are now trash in space.
There are more than 17,000 pieces of space debris that have been recorded.
CNSA said that most debris came form satellites, rockets, spacecraft, tools and miscellaneous items discarded by astronauts.
Scientists estimate that there have been more than 200 spacecraft destroyed in the space era, with an increasing number of collisions in recent years.
As of Sept. 1, 2015, over 1,300 satellites were in orbit, with more than 500 launched by the USA, over 140 by China and over 130 by Russia.
Many countries are expected to send small satellites into space that would raise the risks of collision.
Scientists are looking for solutions such as the development of space robots to clean up debris.