Sergei Petrovskii is a Russian-born British mathematician whose research mostly focuses on modeling of complex ecological systems.
In 2015, he led a study that found that if the ocean temperature were to increase by about six degrees Celsius due to global warming, phytoplankton might stop producing oxygen.
Petrovskii said, "About two thirds of the planet's total atmospheric oxygen is produced by ocean phytoplankton - and therefore cessation would result in the depletion of atmospheric oxygen on a global scale.
Petrovskii's study appeared in the Bulletin of Mathematical Biology.
[5][6] Contrary to a commonly used paradigm of alien species spread by a travelling population front, in the patchy invasion the invasive species spreads into new areas by creating individual patches not preceded by a front propagation.