New Calculation Finds we are close to the Kessler Syndrome [video]

My understanding was always that LEO is much less of a Kessler risk due to atmospheric friction - ie: in the absence of active control and regular correction, LEO objects will gradually de-orbit themselves. It's the the higher geostationary orbits that pose the problem.

Depends on where in LEO. Explorer I had a perigree of about 350km and lasted for 12 years, though the orbit was highly elliptical. 900km and above is stable for thousands of years and well within the (circular orbit) LEO ceiling of 2000km.